Substrate processing apparatus and substrate processing method

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

Technical Field

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. The substrate is, for example, a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (Electroluminescence), a substrate for an FPD (Flat Panel Display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, or a substrate for a solar cell.

Background Art

[0002] Conventionally, as this type of apparatus, there is an apparatus for processing a substrate (see, for example, Patent Document 1). This apparatus includes a chuck table, a water-sealed vacuum pump, a drain tank, a circulation path, and a heat exchanger. [

[0003] The chuck table has a substrate to be processed placed thereon and machining water supplied thereto. Part of the machining water and air supplied to the chuck table are stored in the drain tank through a suction path by suction of the water-sealed vacuum pump. One end of the circulation path is connected to the drain tank in a communicating manner, and the other end is connected to the water-sealing water supply port of the water-sealed vacuum pump through a heat exchanger in a communicating manner. The machining water stored in the drain tank is cooled by the heat exchanger through the circulation path. Thereby, it is not necessary to replenish the water-sealed vacuum pump with newly cooled water-sealing water, and it can be configured in a complete circulation type. The drain tank separates the machining water, the water-sealing water, and air, and discharges the air to the atmosphere. The drain tank is connected at the lower part to a discharge pipe provided with an on-off valve, and is configured to be able to drain water by operating the on-off valve.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, conventional examples with such a configuration have the following problems. In other words, in conventional equipment, a mixture of processing water, water seal water, and air is stored in a wastewater tank. However, depending on the semiconductor processing process, solvents may become mixed into the water seal water. If solvents continue to be mixed into the water seal water, the solvent concentration in the water seal water will increase, and the solvent will volatilize in the wastewater tank, which poses an explosion-proof problem.

[0006] The present invention has been made in view of these circumstances, and aims to provide a substrate processing apparatus and a substrate processing method that do not cause explosion-proof problems even when a solvent is mixed with the water seal. [Means for solving the problem]

[0007] To achieve this objective, the present invention has the following configuration. In other words, the invention described in claim 1 is a substrate processing apparatus for performing predetermined processing on a substrate, comprising: a chamber for housing a substrate and performing processing on the substrate; a solvent gas supply means for supplying a solvent insoluble in pure water as a solvent gas into the chamber; a water-seal vacuum pump for sucking up the gas in the chamber, having a suction port for sucking up the gas, a discharge port for discharging the gas, and a water seal water supply port for supplying water seal water; a pressure reducing pipe, one end of which is connected to the chamber and the other end of which is connected to the suction port; a drain tank, connected to the discharge port, for storing the gas in the chamber containing the solvent and water seal water; a circulation pipe connecting the drain tank and the water seal water supply port of the water-seal vacuum pump; a heat exchanger provided in the circulation pipe for cooling the liquid flowing through the circulation pipe; an exhaust pipe connected to the upper part of the drain tank; and a drain pipe connected to the lower part of the drain tank. A water seal water supply pipe, one end of which is connected to a pure water supply source and the other end of which is connected to the drain tank, and a water seal water on / off valve provided in the water seal water supply pipe for replenishing the drain tank with water seal water, A valve is provided in the drain pipe and controls the flow of liquid in the drain pipe, The system includes a control unit that controls the on / off valve, and the control unit controls the water seal on / off valve based on the liquid level of the drain tank to replenish the water seal water in the drain tank.After operating the water-sealed vacuum pump to reduce the pressure inside the chamber and supplying solvent gas from the solvent gas supply means to process the substrate, once the pressure reduction inside the chamber by the water-sealed vacuum pump is complete, the on / off valve is opened to discharge a portion of the liquid in the drain tank. Ruko It is characterized by the following.

[0008] [Function and Effect] According to the invention described in claim 1, the control unit operates a water-sealed vacuum pump to reduce the pressure inside the chamber and supplies solvent gas from the solvent gas supply means to process the substrate. After the pressure reduction inside the chamber by the water-sealed vacuum pump is completed, the on / off valve is opened to discharge a portion of the liquid in the drain tank. Therefore, it is possible to prevent the concentration of solvent in the liquid in the drain tank from becoming higher than a certain level. As a result, even if the solvent mixes with the water seal water, no explosion-proof problems occur.

[0009] Furthermore, in the present invention, it is preferable that the control unit operates the water-sealed vacuum pump to circulate the liquid in the drain tank through the circulation piping and immediately afterwards open the on-off valve (Claim 2).

[0010] Since the solvent is insoluble in pure water, it separates from the liquid stored in the wastewater tank. Therefore, by circulating the liquid in the wastewater tank through circulation piping, the solvent and pure water are stirred and mixed. Immediately afterward, the shut-off valve is opened, ensuring that the solvent components are reliably discharged from the wastewater tank.

[0011] Furthermore, in the present invention, the invention further comprises a first inert gas supply means for supplying an inert gas into the chamber, and the control unit preferably supplies the inert gas from the first inert gas supply means when performing the circulation (Claim 3).

[0012] When discharging the gas from the chamber and circulating it through the circulation piping, an 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.

[0013] Furthermore, in the present invention, the present invention further comprises a pressure reducing valve provided in the pressure reducing pipe for controlling the flow of gas in the pressure reducing pipe; a processing tank disposed in the chamber for housing a substrate and immersing the substrate in a processing liquid for processing; a chamber drain pipe, one end of which is connected to the bottom of the chamber for discharging the processing liquid stored at the bottom of the chamber; a lower tank, the other end of which is connected to the chamber drain pipe and located below the chamber; a second inert gas supply means for supplying inert gas to the lower tank; a sub-pressure reducing pipe connected to the lower tank and the pressure reducing pipe; and a sub-pressure reducing valve provided in the sub-pressure reducing pipe for controlling the flow of gas in the sub-pressure reducing pipe, wherein the control unit preferably supplies inert gas from the second inert gas supply means with the pressure reducing valve closed and the sub-pressure reducing valve open when the circulation is performed (Claim 4).

[0014] When circulating the fluid, the control unit closes the pressure reducing valve and opens the secondary pressure reducing valve, while supplying inert gas from the second inert gas supply means. Therefore, the water-sealed vacuum pump can be operated to circulate the liquid in the drain tank without affecting the chamber. As a result, the timing for introducing the next substrate into the chamber can be accelerated, thereby improving throughput.

[0015] Furthermore, in the present invention, it is preferable that the drain tank is positioned higher than the water seal water supply port (Claim 5).

[0016] The liquid in the drainage tank moves to the water seal water supply port by gravity. Therefore, no power source such as a pump is required for the circulation piping. As a result, the configuration can be simplified, costs can be reduced, and power consumption can be saved.

[0017] In addition, in the present invention, it is further preferable to include a liquid level sensor that detects a predetermined height position of the liquid level in the drainage tank, and the control unit closes the on-off valve when the liquid level sensor operates after opening the on-off valve (Claim 6).

[0018] It is possible to prevent the liquid in the drainage tank from falling below the predetermined height position. Therefore, it is possible to prevent the operation of the water-sealed vacuum pump from being adversely affected due to insufficient water-sealing water in the water-sealed vacuum pump. The predetermined height position referred to here is the height position corresponding to the capacity of the water-sealing water required for the operation of the water-sealed vacuum pump.

[0019] In addition, 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 inside of the chamber is depressurized (Claim 7).

[0020] When the next substrate is carried into the chamber, the inside of the chamber can immediately start to be depressurized. Therefore, the next process can be smoothly performed.

[0021] In addition, in the present invention, it further includes a water-sealing water supply pipe that supplies water-sealing water to the drainage tank, and a water-sealing water on-off valve provided in the water-sealing water supply pipe for controlling the flow of water-sealing water. The control unit preferably controls the water-sealing water on-off valve based on the liquid level in the drainage tank to replenish the drainage tank with water-sealing water stomach.

[0022] The control unit controls the water-sealing water on-off valve based on the liquid level in the drainage tank to replenish the drainage tank with water-sealing water. Therefore, since the water-sealing water is not insufficient, the depressurization operation by the water-sealed vacuum pump can be stably performed over a long period of time.

[0023] Also, Claim 8The invention described in [reference] is a substrate processing method for performing a predetermined process on a substrate. After accommodating the substrate in a chamber, a decompression step of decompressing the inside of the chamber by a water-sealed vacuum pump, a supply step of supplying a solvent insoluble in pure water as a solvent gas into the chamber while maintaining the decompression, and after the decompression of the chamber by the water-sealed vacuum pump is completed, a discharge step of discharging a part of the liquid in a drainage tank that is connected in communication to the discharge port of the water-sealed vacuum pump and stores the gas in the chamber containing the solvent and the water-sealing water. The steps include replenishing the water seal in the drain tank, It is characterized by implementing the following.

[0024] [Function and Effect] According to the invention described in claim 8 After the decompression step and the supply step, in the discharge step, after the decompression of the chamber by the water-sealed vacuum pump is completed, a part of the liquid in the drainage tank is discharged. Therefore, it is possible to suppress the concentration of the solvent in the liquid in the drainage tank from becoming higher than a certain level. As a result, even when the solvent mixes into the water-sealing water, no explosion-related problems occur.

Effect of the Invention

[0025] According to the substrate processing apparatus according to the present invention, the control unit operates the water-sealed vacuum pump to decompress the inside of the chamber, supplies the solvent gas from the solvent gas supply means, and performs a process on the substrate. After that, when the decompression of the inside of the chamber by the water-sealed vacuum pump is completed, the on-off valve is opened to discharge a part of the liquid in the drainage tank. Therefore, it is possible to suppress the concentration of the solvent in the liquid in the drainage tank from becoming higher than a certain level. As a result, even when the solvent mixes into the water-sealing water, no explosion-related problems occur.

Brief Explanation of Drawings

[0026] [Figure 1] It is a diagram showing the overall configuration of the substrate processing apparatus according to Example 1. [Figure 2] It is a time chart showing an example of the process according to Example 1. [Figure 3] It is a schematic diagram showing the circulation step according to Example 1. [Figure 4] This is a time chart showing an example of the process according to Example 2. [Figure 5] This is a schematic diagram illustrating the circulation steps according to Example 2. [Modes for carrying out the invention]

[0027] Examples of the present invention will be described below. [Examples]

[0028] Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. Figure 1 shows the overall configuration of the substrate processing apparatus according to Example 1.

[0029] <1.Device configuration>

[0030] The substrate processing apparatus 1 performs a predetermined process on a substrate W. The substrate W is, for example, approximately circular in shape. The substrate processing apparatus 1 can perform the same process on multiple substrates W simultaneously. The substrate processing apparatus 1 can also process a single substrate W. The substrate processing apparatus 1 is a so-called batch-type apparatus.

[0031] The substrate processing apparatus 1 includes a chamber 3. The chamber 3 has an input / output port 5 at its top for loading and unloading substrates W. The input / output port 5 is opened and closed by a shutter (not shown). The chamber 3 can be sealed to the outside.

[0032] Chamber 3 contains a treatment tank 7 inside. The treatment tank 7 is located at the bottom of Chamber 3. The treatment tank 7 is spaced apart from the bottom surface of Chamber 3. The bottom surface of the treatment tank 7 is spaced apart from the top surface of the bottom of Chamber 3. The treatment tank 7 has discharge pipes 9 on both sides of its bottom. The discharge pipes 9 supply treatment liquid to the treatment tank 7. The treatment liquid is, for example, pure water or an organic solvent. The treatment tank 7 has a rapid drain valve 11 on its bottom. The rapid drain valve 11 discharges the treatment liquid stored in the treatment tank 7 to the bottom of Chamber 3 in a short time.

[0033] The substrate processing apparatus 1 is equipped with a lifter 13. The lifter 13 can support multiple substrates W on its lower surface. The lifter 13 can support multiple substrates W aligned in the front-to-back direction of the paper. The lifter 13 can also support a single substrate W. The lifter 13 is movable up and down to a first height H1, a second height H2, and a third height H3. The first height H1 is outside the chamber 3 and is the position where the substrates W are transferred to and from a transport mechanism (not shown). The second height H2 is inside the chamber 3 and is above the processing tank 7. The second height H2 is the position where the substrates W are dried. The third height H3 is inside the chamber 3 and is inside the processing tank 7. The third height H3 is the position where the substrates W are treated with a processing liquid in the processing tank 7.

[0034] Chamber 3 comprises 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 composed of a pair of nozzles in the left-right direction. The first nozzle 15, the second nozzle 17, and the third nozzle 19 have their long axes in the direction in which the multiple substrates W are aligned. The first nozzle 15 is located at the highest position in Chamber 3. The second nozzle 17 is located below the first nozzle 15 and above the third nozzle 19. The third nozzle 19 is located below the second nozzle 17 and above the upper edge of the processing tank 7.

[0035] The first nozzle 15 is connected to one end of the supply pipe 21. The other end of the supply pipe 21 is connected to a nitrogen gas supply source 23. The supply pipe 21 is equipped with an on-off valve 25. The nitrogen gas supply source 23 supplies nitrogen gas (dry N2 gas). The on-off valve 25 controls the flow of nitrogen gas in the supply pipe 21.

[0036] The first nozzle 15 described above corresponds to the "first inert gas supply means" in the present invention.

[0037] The second nozzle 17 is connected to one end of the supply pipe 27. The other end of the supply pipe 27 is connected to a water-soluble solvent supply source 29. 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 as vapor. 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 achieve high-concentration supply, it is preferable that the supply of water-soluble solvent vapor from the second nozzle 17 does not use a so-called carrier gas. However, if there is no problem with processing even at a low concentration, a carrier gas may be used for supply.

[0038] A third nozzle 19 is connected to one end of a supply pipe 33. A water-repellent agent 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 agent supply source 35 supplies water-repellent agent vapor. The water-repellent agent is also called a silylation agent. The water-repellent agent contains a solvent that is insoluble in pure water. An example of the insoluble solvent is propylene glycol monomethyl ether acetate (also called PGMEA). The water-repellent agent supply source 35 supplies a treatment liquid containing the insoluble solvent as water-repellent agent vapor. The water-repellent agent removes the treatment liquid adhering to the surface of the substrate W through its water-repellent action, thereby promoting the drying of the substrate W.

[0039] Chamber 3 is equipped with 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 located at the bottom of Chamber 3. The first liquid level sensor 39 and the second liquid level sensor 41 detect a predetermined height position for the liquid level of the processed liquid discharged from the processing tank 7 into Chamber 3. The first liquid level sensor 39 detects the upper limit of the liquid level of the processed liquid that can be stored. The second liquid level sensor 41 detects the lower limit of the liquid level of the processed liquid.

[0040] Chamber 3 is connected to one end of a pressure reducing pipe 43. Chamber 3 is connected to the inside of the chamber through its side wall. A water-sealed vacuum pump 45 is connected to the other end of the pressure reducing pipe 43. The water-sealed vacuum pump 45 is a pump that creates a vacuum inside by filling it with water called sealing water and generating a ring of water using 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 discharges gas from inside the chamber 3, thereby reducing the pressure inside the chamber 3. The pressure reducing valve 47 can adjust the flow rate of the fluid flowing through the pressure reducing pipe 43. The pressure reducing valve 47 can allow or shut off the flow of fluid at the adjusted flow rate.

[0041] The water-sealed vacuum pump 45 is equipped with a suction port 49, a discharge port 51, and a water seal water supply port 53. The water-sealed vacuum pump 45 discharges the gas inside the chamber 3, including vapors of water-soluble solvents and insoluble solvents, through the pressure reducing pipe 43, thereby reducing the pressure inside the chamber 3. The suction port 49 draws in gas. The discharge port 51 discharges the gas drawn in from the suction port 49 together with the water seal water. The water seal water supply port 53 is supplied with water seal water.

[0042] One end of the discharge pipe 55 is connected to the discharge port 51. The other end of the discharge pipe 55 is connected to the drain tank 57. The discharge pipe 55 is always open. In other words, the discharge pipe 55 does not have any on / off valves or other devices to control the flow of fluid inside. The drain tank 57 is positioned higher 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. Consequently, the circulation piping 75, which will be described later, does not require power such as a pump. As a result, the configuration can be simplified and costs can be reduced, as can power consumption.

[0043] The drainage tank 57 stores the gas and liquid discharged from the chamber 3 by the water-sealed vacuum pump 45. The gas in the chamber 3 includes gases such as air and nitrogen gas, as well as vapors of water-soluble and insoluble solvents supplied to the chamber 3. The liquid includes liquefied water-soluble and insoluble solvents (water repellents) supplied to the chamber 3, as well as the water seal water of the water-sealed vacuum pump 45.

[0044] The drain tank 57 is connected to one end of a water seal water supply pipe 59. A pure water supply source 61 is connected to the other end of the water seal water supply pipe 59. The water seal water supply pipe 59 is equipped with a water seal 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 of the liquid level in the drain tank 57. The upper limit position defines, for example, a suitable timing for discharging the liquid from the drain tank 57. The lower limit position defines, for example, a suitable timing for stopping the discharge when the liquid from the drain tank 57 has been discharged. The lower limit position is the height corresponding to the minimum volume of water sealing water required for the operation of the water-sealed vacuum pump 45.

[0045] The wastewater tank 57 is equipped with an exhaust pipe 65. Specifically, one end of the exhaust pipe 65 is connected to the top of the wastewater tank 57. The other end of the exhaust pipe 65 is connected to an exhaust system 67. The exhaust system 67 processes the solvent contained in the gas discharged from the exhaust pipe 65.

[0046] The drainage tank 57 is equipped with a drain pipe 69. Specifically, one end of the drain pipe 69 is connected to the bottom of the drainage tank 57. The other end of the drain pipe 69 is connected to a drainage facility 71. The drainage facility 71 processes the pure water and solvents 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.

[0047] The drain tank 57 is connected to one end of the circulation pipe 75. The drain tank 57 has the circulation pipe 75 at its lower part. The other end of the circulation pipe 75 is connected to the water seal water supply port 53 of the water seal vacuum pump 45. The circulation pipe 75 connects the drain tank 57 and the water seal water supply port 53 of the water seal 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 the water seal water, which consists of pure water containing solvents, etc., flowing through the circulation pipe 75.

[0048] A lower tank 79 is located 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 lower tank 79 is used to discharge the processing liquid stored at the bottom of the chamber 3. One end of the chamber drain pipe 81 is connected to the bottom of the chamber 3. 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.

[0049] One end of a branch pressure reducing pipe 85 is connected to the pressure reducing pipe 43. More specifically, one end of the branch pressure reducing pipe 85 is connected to the chamber 3 side of the pressure reducing valve 47 of the pressure reducing pipe 43. 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 a valve 87. The valve 87 controls the flow of gas in the branch pressure reducing pipe 85. The branch pressure reducing pipe 85 is used when reducing the pressure in the lower tank 79 along with reducing the pressure in the chamber 3.

[0050] The lower tank 79 is equipped with a pressure sensor 89, an upper limit sensor 91, and a lower limit sensor 93. The pressure sensor 89 detects the pressure inside the lower tank 79. The pressure sensor 89 is used to detect when the pressure in the lower tank 79 becomes lower than the pressure inside the chamber 3. The upper limit sensor 91 and the lower limit sensor 93 detect predetermined height positions for the liquid level of the processing liquid inside the lower tank 79. Specifically, the upper limit sensor 91 detects when the liquid level of the processing liquid reaches a predetermined upper height position. The lower limit sensor 93 detects when the liquid level of the processing liquid reaches a predetermined lower height position.

[0051] One end of the auxiliary pressure reducing pipe 95 is connected to the pressure reducing pipe 43. More specifically, one end 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-sealed vacuum pump 45. The other end of the auxiliary pressure reducing pipe 95 is connected to the lower tank 79. The auxiliary pressure reducing pipe 95 is equipped with an auxiliary pressure reducing 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 reducing valve 97 can allow or shut off the flow of gas at the adjusted flow rate.

[0052] The lower tank 79 has one end of a drain pipe 99 connected to its lower section. The other end of the drain pipe 99 is connected to a drainage 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 agent.

[0053] The lower tank 79 has one end of the supply pipe 105 connected to its upper section. The other end of the supply pipe 105 is connected to a nitrogen gas supply source 107. The nitrogen gas supply source 107 supplies nitrogen gas. The supply pipe 105 is equipped with a flow control valve 109. The flow control valve 109 can adjust the flow rate of nitrogen gas in the supply pipe 105. The flow control valve 109 can allow or shut off the flow of nitrogen gas at the adjusted flow rate.

[0054] The supply pipe 105 described above corresponds to the "second inert gas supply means" in the present invention.

[0055] The control unit 111 is equipped with a CPU and memory. The control unit 111 operates each part based on a recipe corresponding to the processing procedure for processing the substrate W (or lot). Based on the liquid level of the drain tank 57, as measured by the liquid level sensor 63, the control unit 111 controls the water seal valve 61 to replenish the drain tank 57 with water seal water. Therefore, since there is no shortage of water seal water, the depressurization operation by the water-sealed vacuum pump 45 can be performed stably over a long period of time.

[0056] The rapid drain valve 11, lifter 13, on-off valve 25, on-off valve 31, on-off valve 37, water-sealed vacuum pump 45, pressure reducing valve 47, water-sealed water on-off valve 61, on-off valve 73, on-off valve 83, on-off valve 87, auxiliary pressure reducing valve 97, on-off valve 103, and flow rate adjustment valve 109 are all operated by the control unit 111. The control unit 111 receives the outputs of 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. For the sake of simplicity in the illustration, in Figure 1, only some of the above-mentioned components are shown with dotted lines as signal lines between them and the control unit 111.

[0057] <2. Specific Examples of Processing>

[0058] Here, the processing of substrate W will be specifically explained with reference to Figures 2 and 3. Figure 2 is a time chart showing an example of the processing according to Example 1. Figure 3 is a schematic diagram showing the circulation steps according to Example 1. In the following explanation, we will describe the processing of substrate W, but the same applies whether it is a single substrate W, multiple substrates W, or a lot. In addition, in the following explanation, everything except the drainage control in the drainage tank 57 is described in a simplified manner. In Figure 2, the symbol O means open and represents an open state, and the symbol C means closed and represents a closed state.

[0059] Initially, it is assumed that pure water is stored in the treatment tank 7. Pure water is supplied to the treatment tank 7 upwards from the ejection pipe 7. At time points 0 to t1, the lifter 13 on which the substrate W is placed is located at a first height H1, which corresponds to the outside of the chamber 3. Also, the on / off valve 25 is open, and nitrogen gas is supplied into the chamber 3 from the first nozzle 15.

[0060] The control unit 111 lowers the lifter 13 to a third height position H3 at time t1. As a result, the substrate W placed on the lifter 13 is washed with pure water. This state is maintained until time t6, during which the pure water washing process is performed. The pure water washing process removes particles and processing liquid that were adhering to the substrate W.

[0061] At time t2, the control unit 111 closes the shut-off valve 25 to stop the supply of nitrogen gas. Furthermore, at time t2, the control unit 111 opens the pressure reducing shut-off valve 47 at a first flow rate. Simultaneously, the control unit 111 operates the water-sealed 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 into the drain tank 57 from the discharge pipe 55. The water seal water in the drain tank 57 is cooled by the heat exchanger 77 through the circulation pipe 75 and supplied again to the water-sealed vacuum pump 45 as water seal water.

[0062] The control unit 111 opens the on-off valve 31 at time t3, when the pressure inside the chamber 3 has been reduced to a certain extent. When the on-off valve 31 is opened, IPA vapor is supplied into the chamber 3 from the second nozzle 17. This state is continued until time t7.

[0063] The control unit 111, for example, opens the auxiliary pressure reducing valve 97 at a second flow rate at time t4. This state is maintained until time t5. In other words, the control unit 111 closes the auxiliary pressure reducing valve 97 at time t5. The second flow rate is greater 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. Because the second flow rate is greater than the first flow rate, the pressure in the lower tank 79 is reduced to a level lower than that of the chamber 3.

[0064] At time t6, the control unit 111 raises the lifter 13 to a second height H2. This causes the substrate W held by the lifter 13 to rise above the level of pure water 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. This performs a replacement treatment on the substrate W. Specifically, the pure water adhering to the substrate W is replaced with IPA, a water-soluble solvent, by IPA vapor. During the replacement treatment, the water-sealed vacuum pump 45 continues to reduce pressure. Therefore, water-sealed water containing dissolved IPA is discharged into the drain tank 57 from the discharge pipe 55.

[0065] At time t6, the control unit 111 raises the lifter 13 to the second height H2 and opens the rapid drain valve 11. As a result, the pure water in the treatment tank 7 is discharged to the bottom of the chamber 3 in a short time.

[0066] At time t6, the control unit 111 opens the on-off valve 37. As a result, water-repellent vapor is supplied into the chamber 3 from the third nozzle 19, and a water-repellent treatment is performed. This makes the front, back, and end faces of the substrate W held by the lifter 13 hydrophobic. In other words, the water-repellent agent adheres to the entire substrate W, which has had its pure water replaced by IPA, and the entire substrate W becomes hydrophobic. This makes it easier for any pure water or water-soluble solvents remaining on the substrate W to detach from the substrate W.

[0067] The control unit 111 closes the on-off valve 31 at time t7. This shuts off the flow of IPA vapor from the second nozzle 17 into the chamber 3.

[0068] The control unit 111 opens the on-off valve 83 between time t8 and t9. This allows the pure water containing IPA and water repellent, which had been stored in the lower part of the chamber 3, to be discharged into the lower tank 79. The lower tank 79 is reduced to a pressure lower than that of the chamber 3 between time t4 and t5. Therefore, even in the reduced-pressure state of the chamber 3, the stored pure water is smoothly discharged into the lower tank 79.

[0069] In this way, the pure water stored in the lower part of chamber 3 is discharged into the lower tank 79. Therefore, the inconvenience of moisture evaporating from the lower part of the chamber 3, which is under reduced pressure, and adhering to the substrate W, which would hinder drying, can be avoided.

[0070] At time t10, the control unit 111 closes the on-off valve 37. This stops the supply of the water-repellent agent into the chamber 3. Therefore, the water-repellent treatment of the substrate W is completed.

[0071] At time t10, the control unit 111 opens the on-off valve 25 to supply nitrogen gas into the chamber 3 from the first nozzle 15. This supply of nitrogen gas continues until the next substrate W is brought 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-sealed vacuum pump 45. Therefore, the pressure inside the chamber 3 is returned to approximately atmospheric pressure without any pressurization or depressurization. In other words, the inside of the chamber 3 is opened to atmospheric pressure. However, the exhaust operation of the chamber 3 by the water-sealed vacuum pump 45 continues. The control unit 111 raises the lifter 13 to the first height H1. As a result, the processed substrate W is carried out of the chamber 3.

[0072] Furthermore, even after the substrate W has been removed, the operation of the water-sealed vacuum pump 45 continues until time t11. At this time, as shown in Figure 3, nitrogen gas is supplied to the chamber 3 from the first nozzle 15, and the water-sealed vacuum pump 45 discharges the gas inside the chamber 3. Therefore, the water seal water in the drain tank 57 can be circulated without reducing the pressure inside the chamber 3. As a result, as shown in Figure 3, the water seal water containing IPA and water repellent is circulated to the drain tank 57 via the circulation pipe 75. At this time, the water seal water is cooled by the heat exchanger 77, so the water seal water that has been heated by the operation of the water-sealed vacuum pump 45 is cooled. Therefore, circulating the water seal water does not adversely affect the operation of the water-sealed vacuum pump 45. In addition, the water seal water contains IPA and water repellent. Therefore, the water-soluble solvent and water repellent are efficiently concentrated by cooling.

[0073] The control unit 111 stops the water-seal 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 t12. As a result, a portion of the water seal water stored in the drainage tank 57 is discharged to the drainage equipment 71. This water seal water is concentrated with water-soluble solvents and water repellents, and since it is circulated, the water repellents, which are insoluble in pure water, are mixed with the pure water by agitation. Therefore, even if the water seal water is discharged from the drainage pipe 69 located at the bottom of the drainage tank 57, the water repellents can be properly discharged.

[0074] The control unit 111 closes the on-off valve 73 at t12, before the next substrate W is loaded at t13. This allows the water-sealing vacuum pump 45 to be activated immediately upon loading the next substrate W into the chamber 3, thereby starting to reduce the pressure inside the chamber 3. Consequently, the next processing can be carried out smoothly.

[0075] The control unit 111 closes the on-off valve 73 at time t12, but it may also close the on-off valve 73 when the liquid level reaches a predetermined level detected by the liquid level sensor 63. This prevents adverse effects on the operation of the water-sealed vacuum pump 45 caused by excessive discharge of water seal water or insufficient water seal water.

[0076] Furthermore, the water-repellent agent is lighter than pure water. Therefore, if agitation is not performed to circulate it through the circulation pipe 75, the water-repellent agent will separate and form a layer on top of the pure water. As a result, if drainage is performed from the bottom of the drainage tank 57 in this state, the water-repellent agent will not be discharged. If such discharge continues, the concentration of the water-repellent agent in the drainage tank 57 will increase, posing an explosion-proof problem. According to this embodiment, the water-repellent agent is discharged appropriately, thus solving the explosion-proof problem. In addition, the drainage equipment 71 processes the wastewater assuming that the concentration of the water-repellent agent is above a predetermined value. Therefore, if the concentration of the water-repellent agent is too low, there is a risk that the wastewater may not be treated properly. According to this embodiment, wastewater can be treated appropriately by agitation.

[0077] Alternatively, a concentration meter may be installed in the drainage tank 57 to measure the concentration of the water repellent in the water seal water. When the concentration reaches or exceeds this level, and the processing of the substrate W is completed, the water seal vacuum pump 45 may be stopped and the on-off valve 73 opened. This reduces the circulation time from t10 to t11. As a result, the operating time of the water seal vacuum pump 45 required for stirring can be shortened, thus reducing power consumption. The concentration of the water repellent may be measured by installing a concentration meter at the top of the drainage tank 57. In other words, the concentration of the water repellent that has evaporated from the water seal water stored in the drainage tank 57 is measured.

[0078] The T1 period from t2 to t10, as described above, corresponds to the "decompression step" in this invention. The T2 period from t6 to t10, as described above, corresponds to the "supply step" in this invention. The T3 period from t10 to t11, as described above, corresponds to the "circulation step" in this invention. The T4 period from t11 to t12, as described above, corresponds to the "discharge step" in this invention.

[0079] In this embodiment, the control unit 111 operates the water-sealed vacuum pump 45 to reduce the pressure inside the chamber 3 and supplies a water-repellent agent from the third nozzle 19 to treat the substrate W. After the pressure reduction inside the chamber 3 by the water-sealed vacuum pump 45 is completed, the on-off valve 73 is opened to discharge a portion of the water-seal water in the drain tank 57. Therefore, it is possible to prevent the concentration of the water-repellent agent in the water-seal water in the drain tank 57 from becoming higher than a certain level. As a result, even if the water-repellent agent is mixed into the water-seal water, no explosion-proof problems occur. [Examples]

[0080] Next, Embodiment 2 of the present invention will be described with reference to the drawings. The configuration of the substrate processing apparatus 1 is the same as that of Embodiment 1 described above. The difference between Embodiment 2 and Embodiment 1 is the control by the control unit 111. Therefore, only an example of the processing will be described with reference to Figures 4 and 5.

[0081] Figure 4 is a time chart showing an example of the process according to Example 2. Figure 5 is a schematic diagram representing the cyclical steps according to Example 2.

[0082] In Embodiment 2, the control performed by the control unit 111 during the T3 period from t10 to t11 differs from that of Embodiment 1 described above. At t10, when the depressurization of the chamber 3 is complete, the control unit 111 closes the depressurization valve 47. Furthermore, at t10, when the depressurization of the chamber 3 is complete, the control unit 111 opens the auxiliary depressurization valve 97 and the flow control valve 109. As a result, the lower tank 79 is first opened to atmospheric pressure. At t11, when the circulation is complete, the control unit 111 closes the auxiliary depressurization valve 97 and the flow control valve 109.

[0083] During period T3, the water-sealed vacuum pump 45 discharges nitrogen gas from the lower tank 79 to the drain tank 57. During this time, as shown in Figure 5, the water seal water is circulated through the circulation pipe 75. Immediately afterward, at time t11-t12, the on-off valve 73 is opened, and a portion of the water seal water stored in the drain tank 57 is discharged to the drainage equipment 71.

[0084] This embodiment provides the same effects as the embodiment 1 described above. Furthermore, in this embodiment, when circulating, the control unit 111 closes the pressure reducing valve 47 and opens the sub-pressure reducing valve 97, while supplying inert gas from the nitrogen gas supply source 107. Therefore, the water-sealed vacuum pump 45 can be operated and the water-sealed water in the drain tank 57 can be circulated without affecting the chamber 3. As a result, for example, as shown by the dotted line in Figure 4, the timing of introducing the substrate W into the chamber 3 at t10a can be advanced. Therefore, an improvement in throughput can be expected.

[0085] The present invention is not limited to the embodiments described above, and can be modified and implemented as follows.

[0086] (1) In the above-described embodiments 1 and 2, the on-off valve 73 is opened and the liquid in the drain tank 57 is discharged immediately after it has been circulated in the circulation pipe 75. However, the present invention is not limited to such embodiments. For example, the on-off valve 73 may be opened not immediately, but after a predetermined time (several minutes).

[0087] (2) In the above-described embodiment 1, nitrogen gas is supplied to the chamber 3 when circulation is performed. However, the present invention is not limited to this form. For example, the chamber 3 may be subjected to negative pressure without supplying nitrogen gas to it.

[0088] (3) In the above-described embodiment 2, the auxiliary pressure reducing pipe 95 and the lower tank 79 are exhausted to circulate the water seal water. However, the present invention is not limited to this form. For example, a three-way valve may be provided in the pressure reducing pipe 43 so that it can be switched between a state in communication with the chamber 3 and a state in communication with the atmosphere. When circulating the water seal water, the three-way valve may be switched to the state in communication with the atmosphere. This allows for circulation without affecting the chamber 3 or the lower tank 79. Therefore, the loading of substrates W into the chamber 3 can be brought forward, and the timing of depressurizing the lower tank 79 can be advanced. As a result, an improvement in throughput can be expected.

[0089] (4) In each of the embodiments 1 and 2 described above, the drain tank 57 is positioned higher than the water seal water supply port 53 of the water seal vacuum pump 45. However, the present invention is not limited to this configuration. For example, the drain tank 57 may be positioned lower than the water seal water supply port 53 of the water seal vacuum pump 45. In this case, a pump is placed in the circulation piping 75 to actively circulate the water seal water with the pump.

[0090] (5) In each of the above-described Examples 1 and 2, a water repellent containing pegmea (PGMEA) was used as an example of a solvent insoluble in pure water. However, the present invention is not limited to water repellents containing pegmea. [Explanation of Symbols]

[0091] W… Circuit board 1 ... Substrate processing equipment 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 tube 45... Water-sealed vacuum pump 47… Pressure reducing valve 49 … Suction port 51 … Outlet 53 … Water seal water supply port 55 … Discharge pipe 57… Drainage tank 59 … Water seal water supply pipe 61... Water seal water shut-off valve 63… Liquid level sensor 65… Exhaust pipe 69 ... Drainage pipe 73… Shut-off valve 75 … Circulation piping 77 … Heat exchanger 79… Lower tank 81... Chamber drain pipe 95 … Sub-pressure reducing tube 97… Sub-pressure reducing valve 105 … Supply pipe 109… Flow control valve 111 ... Control Unit

Claims

1. In a substrate processing apparatus that performs predetermined processing on a substrate, A chamber for housing a substrate and processing the substrate, A solvent gas supply means for supplying a solvent insoluble in pure water as a solvent gas into the chamber, A water-sealed vacuum pump for sucking gas from the chamber, comprising a suction port for sucking gas, a discharge port for discharging gas, and a water seal water supply port for supplying water seal water, A pressure reducing pipe, one end of which is connected to the chamber and the other end of which is connected to the suction port, A drain tank connected to the aforementioned outlet, which stores the gas in the chamber containing the solvent and the water seal water, A circulation pipe connects the drain tank and the water seal water supply port of the water-sealed vacuum pump, A heat exchanger is provided in the aforementioned circulation piping and cools the liquid flowing through the circulation piping, An exhaust pipe is connected to the upper part of the aforementioned drainage tank, A drain pipe is connected to the lower part of the aforementioned drainage tank, A water seal water supply pipe, one end of which is connected to a pure water supply source and the other end of which is connected to the drain tank, A water seal water supply pipe is provided with a water seal water shut-off valve for replenishing the water seal water in the drain tank, A valve is provided in the drain pipe and controls the flow of liquid in the drain pipe, The system includes a control unit that controls the on / off valve, The control unit, The water seal valve is controlled based on the liquid level of the drain tank to replenish the drain tank with water seal water. After operating the water-sealed vacuum pump to reduce the pressure inside the chamber and supplying solvent gas from the solvent gas supply means to process the substrate, once the pressure reduction inside the chamber by the water-sealed vacuum pump is complete, the on / off valve is opened to discharge a portion of the liquid in the drain tank. A substrate processing apparatus characterized by the following:

2. In the substrate processing apparatus according to claim 1, The substrate processing apparatus is characterized in that the control unit operates the water-sealed vacuum pump to circulate the liquid in the drain tank through the circulation piping, and immediately afterwards opens the on-off valve.

3. In the substrate processing apparatus according to claim 2, The chamber further comprises a first inert gas supply means for supplying an inert gas into the chamber, The substrate processing apparatus is characterized in that the control unit supplies inert gas from the first inert gas supply means when the circulation is performed.

4. In the substrate processing apparatus according to claim 2, A pressure reducing valve is provided in the pressure reducing pipe and controls the flow of gas in the pressure reducing pipe, A processing tank is placed inside the chamber and contains a substrate, which is immersed in a processing liquid to perform processing. One end of the chamber is connected to the bottom of the chamber, and the chamber drain pipe is used to discharge the processing liquid stored at the bottom of the chamber. The other end of the chamber drain pipe is connected to a lower tank located below the chamber, A second inert gas supply means for supplying inert gas to the lower tank, A sub-pressure reducing pipe is connected to the lower tank and the pressure reducing pipe, A secondary pressure reducing valve is provided in the secondary pressure reducing pipe and controls the flow of gas in the secondary pressure reducing pipe, Furthermore, The substrate processing apparatus is characterized in that, when the circulation is performed, the control unit closes the pressure reducing valve and opens the auxiliary pressure reducing valve, while supplying inert gas from the second inert gas supply means.

5. In the substrate processing apparatus according to claim 1 or 2, The substrate processing apparatus is characterized in that the drain tank is located at a position higher than the water seal water supply port.

6. In the substrate processing apparatus according to claim 1 or 2, The drainage tank further includes a liquid level sensor that detects a predetermined height position of the liquid level, The control unit is characterized in that, after opening the on-off valve, it closes the on-off valve when the liquid level sensor is activated.

7. In the substrate processing apparatus according to claim 1 or 2, The control unit is characterized by closing the on / off valve before the next substrate is loaded into the chamber and the pressure inside the chamber is reduced.

8. In a substrate processing method that performs a predetermined process on a substrate, After placing the substrate in the chamber, a depressurization step is performed to reduce the pressure inside the chamber using a water-sealed vacuum pump. A supply step in which a solvent insoluble in pure water is supplied as a solvent gas into the chamber while maintaining the aforementioned reduced pressure, After the depressurization of the chamber by the water-sealed vacuum pump is completed, a discharge step is performed to discharge a portion of the liquid in a drain tank that is connected to the discharge port of the water-sealed vacuum pump and stores the gas in the chamber containing the solvent and the water seal water, The steps include replenishing the water seal in the drain tank, A substrate processing method characterized by performing the following:

9. In the substrate processing method described in claim 8, After the pressure reduction of the chamber by the water-sealed vacuum pump is completed, a further circulation step is performed to circulate the liquid in the drain tank via a circulation pipe, one end of which is connected to the drain tank and the other end of which is connected to the water-sealed vacuum pump. A substrate processing method characterized in that the discharge in the discharge step is performed immediately after the circulation step.

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