JP2010171295A - Out-of-liquid control method in process liquid supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an out-of-liquid control method which prevents a liquid drop depending on characteristics of different liquids by controlling an open and close valve and a suck back valve individually without performing complicated valve control, and avoids the out-of-liquid condition for maintaining the optimum state before discharging in the next step. <P>SOLUTION: In a process liquid supply system provided with an open and close valve and a suck back valve in a process liquid supply flow path connecting a process liquid supply source to a process liquid supply nozzle, in the out-of-liquid control method which prevents the out-of-liquid condition of the process liquid from the ejection port of the process liquid supply nozzle, when the open and close valve is closed, the valve closing operation of the open and close valve and the suction operation of the suck back valve are individually performed based on drive signals, and the suction operation of the suck back valve (the suction-setup operation, the suction starting operation) is controlled concurrently with the valve closing operation of the open and close valve depending on characteristics of liquid to suppress an inner pressure behavior in closing the open and close valve. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid breakage control method in a processing liquid supply system such as a semiconductor wafer or a liquid crystal glass substrate (FPD substrate).

  In general, in the manufacture of semiconductor devices, for example, a resist solution is supplied (discharged) from a nozzle to a semiconductor wafer, an FPD substrate, etc. (hereinafter referred to as a wafer) and applied, and a resist film formed thereby is applied to a predetermined circuit pattern. The circuit pattern is formed on the resist film by performing an exposure process in accordance with the exposure pattern and developing the exposure pattern.

  In such a photolithography process, with the recent miniaturization and thinning of device patterns, the uniformity of the film thickness of a resist solution that is a processing solution has become an important factor. For this reason, when the supply (discharge) of the resist solution is stopped, it is necessary to adjust the drainage so that the resist solution does not drip from the discharge port of the nozzle.

  This liquid breakage is adjusted mainly by the closing time of the on-off valve provided in the supply flow path. The valve closing time is adjusted for each supply line, such as the resist solution viscosity and surface tension characteristics and piping conditions. In addition, the optimum values vary depending on the discharge conditions (mainly discharge rate, that is, discharge flow rate, discharge flow rate, etc.) even within the same supply line where these are the same conditions. Needed adjustment.

  Conventionally, as a technique for preventing dripping, a rapid valve closing in which the streamline of the resist solution flowing out from a preset discharge port is constricted from the time when the opening / closing valve is instructed to close under the drive action of an electric actuator. A step of controlling the lift amount of the valve body with respect to the time to reach the operating position, and after reaching the rapid valve closing operation position, the valve body of the on-off valve is set to the closed position without controlling the lift amount. And a step of displacing the valve body with respect to the time from the time when the opening / closing valve is instructed to reach the rapid valve closing operation position where the flow line of the resist solution flowing out from the discharge port becomes constricted. A liquid dripping prevention method is known in which the lift amount is controlled according to an operation control pattern stored in a plurality of storage means according to the characteristics of the resist liquid (see, for example, Patent Document 1).

  By the way, the open / close valve has an internal pressure behavior in which the internal pressure fluctuates during the open / close operation. That is, as shown in FIG. 9, when the opening / closing valve is opened (at the start of discharge), a water hammer phenomenon as indicated by I in FIG. 9 occurs. This phenomenon depends on the pressure on the primary side of the open / close valve, the valve opening speed, the valve opening (fixed), and the like. On the other hand, when the open / close valve is closed (at the end of discharge), a negative pressure is generated due to the inertia of the fluid, and a water hammer phenomenon as indicated by II in FIG. 9 occurs. This phenomenon depends on the pressure (flow velocity) on the primary side of the open / close valve, the valve closing speed, the valve opening (fixed), and the like.

Japanese Patent No. 3493322 (Claims, FIGS. 8 and 9)

  However, since the technique of Patent Document 1 is a technique for preventing the dripping by controlling the lift amount of the valve body of the opening / closing valve, the valve body of the opening / closing valve is closed slowly, that is, the valve closing time of the opening / closing valve is lengthened. This makes it possible to suppress the water hammer phenomenon (pressure pulsation) when the valve is closed (at the end of discharge), but the valve operation tends to vary as the valve closing time increases, so the valve is controlled in a complicated manner. There is a need. In addition, there is a concern that only the closing operation control of the opening / closing valve is not sufficient to maintain the optimum liquid run-out state, that is, the optimum state before discharge in the next process, according to the characteristics of different liquids. Here, the optimum state before discharging in the next process is a state in which the processing liquid in the nozzle outlet after the previous process can be discharged in an optimal state when discharging in the next process, and waiting before discharging. A state in which the processing liquid is not exposed to the tip of the discharge port or dried (crystallized) inside the discharge port.

  This invention was made in view of the above circumstances, and without performing complicated control of the valve, the open / close valve and the suck back valve are separately controlled to prevent dripping according to the characteristics of different liquids, It is an object of the present invention to provide a liquid shortage control method capable of stabilizing liquid shortage that maintains an optimum state before discharge in the next step.

  In order to solve the above-mentioned problem, the liquid runout control method in the processing liquid supply system according to the present invention includes an open / close valve and a suck-back valve in a processing liquid supply channel connecting a processing liquid supply source and a processing liquid supply nozzle. In the processing liquid supply system, when the open / close valve is closed, a liquid runout control method for preventing dripping of the processing liquid from the discharge port of the processing liquid supply nozzle, The valve closing operation of the opening / closing valve and the suction operation of the suck back valve are performed based on different driving signals, and the suction operation of the suck back valve is performed with a treatment liquid to suppress the internal pressure behavior when the opening / closing valve is closed. In accordance with the characteristics of the opening / closing valve, the valve is controlled to be overlapped with the closing operation of the opening / closing valve (claim 1).

  By configuring in this way, the internal pressure behavior (pressure pulsation) such as the water hammer phenomenon, in which negative pressure is generated due to the inertia of the processing liquid when the open / close valve is closed, the open / close valve closing control and the suck back valve suction It can be suppressed by operation control, and the timing of running out of liquid can be stabilized.

  In the present invention, when the characteristic of the processing liquid is low viscosity, for example, 10 cp or less {normal valve closing time up to 300 msec level (water hammer minimum), the level at which the liquid does not cut cleanly at the tip of the processing liquid supply nozzle} It is preferable to control the suction set-up operation of the suck back valve so as to overlap with the valve closing operation of the open / close valve.

  By constructing in this way, the suction setup operation of the suck back valve is overlapped with the closing operation of the open / close valve, so that the dripping at the time of closing of the processing liquid having a low viscosity, for example, 10 cp or less, that is liable to be dripped can be reduced. It can be prevented by controlling the suction operation of the back valve, and it is possible to stabilize the running out of the treatment liquid having a low viscosity, for example, 10 cp or less, which tends to be exposed to the discharge nozzle tip at the end of the discharge.

  Further, in the present invention, when the characteristic of the processing liquid is high viscosity, for example, 80 cp or more {the level at which the liquid does not run out at the front end of the processing liquid supply nozzle even when the valve closing time is the shortest (maximum water hammer)> It is preferable that the suction start operation of the suck back valve is controlled so as to overlap the valve closing operation of the open / close valve.

  By configuring in this way, the suction start operation of the suck back valve is overlapped with the valve closing operation of the open / close valve to prevent dripping when the processing liquid is closed, and at the end of discharge, the discharge port of the supply nozzle By increasing the internal behavior (pressure pulsation) at the time of valve closing of the processing liquid having a high viscosity, for example, 80 cp or higher, which tends to run out at the inner position, it is possible to improve the liquid running effect.

  According to this invention, since it is configured as described above, the open / close valve and the suck back valve are separately controlled to prevent dripping according to the characteristics of different liquids without performing complicated control of the valves. At the same time, it is possible to stabilize the out of liquid that maintains the optimum state before discharging in the next step.

1 is a schematic plan view showing an entire resist solution coating / development processing system to which a processing solution supply system according to the present invention is applied. It is a schematic front view of the said processing system. It is a schematic rear view of the processing system. It is a schematic longitudinal cross-sectional view which shows an example of the coating processing apparatus in the process liquid supply system which concerns on this invention. 1 is a schematic configuration diagram of a processing liquid supply system according to the present invention. It is a time chart which shows 1st Embodiment of the supply / stop state of the process liquid in the process liquid supply system which concerns on this invention. It is a time chart which shows 2nd Embodiment of the supply / stop state of the process liquid in the process liquid supply system which concerns on this invention. It is a time chart which shows an example of the supply / stop state of the process liquid in the conventional process liquid supply system. It is a graph which shows the internal pressure behavior at the time of discharge of the process liquid supply nozzle in this invention. It is principal part sectional drawing which shows the liquid cutting position and suck back height of the defect of a processing liquid of a low viscosity and a low surface tension. It is principal part sectional drawing which shows the liquid cutting | disconnection position and suck back height of the processing liquid of high viscosity and the high surface tension defect. It is principal part sectional drawing which shows the state with the favorable liquid cutting | disconnection position and suckback height of a process liquid.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, a case where the processing liquid supply system according to the present invention is applied to a resist coating processing apparatus in a semiconductor wafer resist coating / development processing system will be described.

  FIG. 1 is a schematic plan view showing a resist solution coating / development processing system for a semiconductor wafer having a processing solution supply system according to the present invention, FIG. 2 is a schematic front view of the resist solution coating / development processing system, and FIG. 1 is a schematic rear view of a resist solution coating / development processing system.

  As shown in FIG. 1, the resist solution application / development processing system S carries, for example, 25 wafers W from the outside in units of cassettes to / from the resist solution application / development processing system S. A cassette station S1 for loading and unloading the wafer W, and a processing station S2 provided adjacent to the cassette station S1 and arranged in a multi-stage with various processing units for performing predetermined processing in a single wafer type in the coating and developing process. And an interface unit S3 for transferring the wafer W to and from an exposure apparatus (not shown) provided adjacent to the processing station S2.

  In the cassette station S1, a plurality of cassettes C can be placed in a row in a horizontal X direction at a predetermined position on the cassette placement table A. The cassette station S1 is provided with a wafer transfer arm D that can move along the X direction on the transfer path B. The wafer transfer arm D is also movable in the wafer arrangement direction (Z direction; vertical direction) of the wafers W accommodated in the cassette C, and is selective to the wafers W in each cassette C arranged in the X direction. Is configured to be accessible.

  Further, the wafer transfer arm D is configured to be rotatable in the θ direction about the Z axis, and as described later, with respect to the transition device (TRS) 31 belonging to the third processing unit group G3 on the processing station S2 side. Even it is configured to be accessible.

  The processing station S2 includes, for example, five processing unit groups G1 to G5 in which a plurality of processing units are arranged in multiple stages. As shown in FIG. 1, on the front side of the processing station S2, a first processing unit group G1 and a second processing unit group G2 are sequentially arranged from the cassette station S1 side. On the back side of the processing station S2, a third processing unit group G3, a fourth processing unit group G4, and a fifth processing unit group G5 are sequentially arranged from the cassette station S1 side. A first transport mechanism 110 is provided between the third processing unit group G3 and the fourth processing unit group G4. The first transport mechanism 110 is configured to selectively access the first processing unit group G1, the third processing unit group G3, and the fourth processing unit group G4 to transport the wafer W. A second transport mechanism 120 is provided between the fourth processing unit group G4 and the fifth processing unit group G5. The second transfer mechanism 120 is configured to selectively access the second processing unit group G2, the fourth processing unit group G4, and the fifth processing unit group G5 to transfer the wafer W.

  As shown in FIG. 2, the first processing unit group G1 is a liquid processing unit that supplies a predetermined processing liquid to the wafer W and performs processing, for example, a wafer W is coated with a resist solution. Resist coating units (COT) 10, 11, and 12 having a resist coating processing apparatus having a liquid supply system, and a bottom for forming an antireflection film by applying an ultraviolet curable resin liquid for preventing reflection of light during exposure. Coating units (BARC) 13 and 14 are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units (DEV) 20 to 24 that perform development processing on the wafer W are stacked in five stages in order from the bottom. Further, at the bottom of the first processing unit group G1 and the second processing unit group G2, a chemical chamber (CHM) for supplying various processing liquids to the liquid processing units in the processing unit groups G1 and G2. 25 and 26 are provided, respectively.

  On the other hand, as shown in FIG. 3, the third processing unit group G3 includes, in order from the bottom, a temperature control unit (TCP) 30, a transition device (TRS) 31 for delivering the wafer W, and a highly accurate temperature. Heat treatment units (ULHP) 32 to 38 that heat-treat the wafer W under management are stacked in nine stages.

  In the fourth processing unit group G4, for example, a high-precision temperature control unit (CPL) 40, pre-baking units (PAB) 41 to 44 for heat-treating the resist-coated wafer W, and the wafer W after development processing are heat-treated. Post baking units (POST) 45 to 49 are stacked in 10 stages in order from the bottom.

  In the fifth processing unit group G5, a plurality of heat treatment units that heat-treat the wafer W, for example, high-precision temperature control units (CPL) 50 to 53, post-exposure baking units (PEB) 54 to heat-treat the exposed wafer W, 59 are stacked in 10 steps from the bottom.

  Further, as shown in FIG. 1, a plurality of processing units are arranged on the positive side in the X direction of the first transfer mechanism 110. For example, as shown in FIG. 3, the wafer W is subjected to a hydrophobic treatment. Adhesion units (AD) 80 and 81 and heating units (HP) 82 and 83 for heating the wafer W are stacked in four stages in order from the bottom. Further, as shown in FIG. 9, for example, a peripheral exposure unit (WEE) 84 that selectively exposes only the edge portion of the wafer W is disposed on the back side of the second transfer mechanism 120.

  As shown in FIG. 2, an air conditioning unit 90 for air-conditioning the inside of each block is provided above the blocks of the cassette station S1, the processing station S2, and the interface unit S3. The air conditioning unit 90 can adjust the cassette station S1, the processing station S2, and the interface unit S3 to a predetermined temperature and humidity. As shown in FIG. 3, for example, a predetermined gas is supplied to each device in the third processing unit group G3, the fourth processing unit group G4, and the fifth processing unit group G5 in the upper part of the processing station S2. For example, gas supply units 91 that are gas supply means such as FFU (fan filter unit) to be supplied are provided. The gas supply unit 91 can blow the gas at a predetermined flow rate after removing impurities from the gas adjusted to a predetermined temperature and humidity.

  As shown in FIG. 1, the interface unit S3 includes a first interface unit 100 and a second interface unit 101 in order from the processing station S2 side. In the first interface unit 100, a wafer transfer arm 102 is disposed at a position corresponding to the fifth processing unit group G5. For example, buffer cassettes 103 (on the back side in FIG. 1) and 104 (on the front side in FIG. 1) are installed on both sides of the wafer transfer arm 102 in the X direction. The wafer transfer arm 102 can access the heat treatment apparatus and the buffer cassettes 103 and 104 in the fifth processing unit group G5. The second interface unit 101 is provided with a wafer transfer arm 106 that moves on a transfer path 105 provided in the X direction. The wafer transfer arm 106 is movable in the Z direction and rotatable in the θ direction, and can access the buffer cassette 104 and an exposure apparatus (not shown) adjacent to the second interface unit 101. . Therefore, the wafer W in the processing station S2 can be transferred to the exposure apparatus via the wafer transfer arm 102, the buffer cassette 104, and the wafer transfer arm 106, and the wafer W after the exposure process is transferred to the wafer transfer arm 106 and the buffer. It can be transferred into the processing station S <b> 2 via the cassette 104 and the wafer transfer arm 102.

  The resist coating processing apparatus 15 having the processing liquid supply system according to the present invention applied to the resist coating units (COT) 10, 11, and 12 is disposed in a processing container 60 that can seal the inside. ing. As shown in FIG. 4, a loading / unloading port 60 a for the wafer W is formed on one side of the processing container 60 on the surface facing the transfer region of the first transfer mechanism 110 serving as a transfer unit for the wafer W. An opening / closing shutter 63 is provided at 60 a so as to be opened and closed by an opening / closing lift cylinder 64.

  As shown in FIG. 4, the resist coating apparatus 15 is connected to the spin chuck 16 as a holding means for the wafer W by vacuum suction holding the wafer W horizontally on the upper surface thereof, and the spin chuck 16 via a shaft portion 16a. A rotation mechanism 16b formed by, for example, a servo motor for rotating the wafer W in a horizontal plane, and a collection nozzle 70 including a processing liquid supply nozzle 70a for supplying (discharging) a resist liquid to the surface of the wafer W are provided. Yes.

  The collective nozzle 70 is provided at the distal end of a turning arm 65 as a moving member that turns around a turning shaft 66. The collecting nozzle 70 has a processing liquid supply nozzle 70a connected to a later-described second processing liquid supply pipe 7b, which is a processing liquid supply flow path, for discharging a resist liquid, and a solvent supply source via the solvent supply pipe 70c. A solvent supply nozzle 70b that is connected to 70d and discharges the solvent is provided. These nozzles 70a and 70b are juxtaposed inwardly in the radial direction of the wafer W, and both are open on the lower surface of the collective nozzle 70. . That is, the processing liquid supply nozzle 70a and the solvent supply nozzle 70b are arranged so that the processing liquid supply nozzle 70a is located on the radially inner side of the wafer W and the solvent supply nozzle 70b is located on the radially outer side of the wafer W. They are juxtaposed at a predetermined interval. Then, the resist solution supplied from the processing solution supply nozzle 70a is discharged from the second processing solution supply line 7b, and the solvent supplied from the solvent supply nozzle 70b is discharged from the solvent supply line 70c. It is configured as follows.

  Further, as shown in FIG. 4, the rotation arm 65 is fixed in a horizontal posture on an upper portion of a rotation shaft 66 provided vertically outside the processing container 60, and a rotation mechanism 67 (nozzle of the rotation shaft 66). The moving mechanism) is configured to rotate within a horizontal plane. The rotating arm 65 moves between a state where it is moved near the center of the wafer W and a state where it is moved to a standby position (home position) outside the processing container 60 above the wafer W. A process for forming a coating film on the wafer W is performed by moving the rotating arm 65 between them.

  In the processing container 60, an outer cup 61 that can move up and down to surround the outer periphery of the wafer W and an inner cup 62 that is disposed on the lower side of the wafer W are provided. In the processing space 60b of the processing container 60, a ventilation channel 60c is formed between the outer cup 61 and the inner cup 62 so that the downflow clean air flowing from above flows downward.

  Next, a processing liquid supply apparatus constituting the processing liquid supply system according to the present invention will be described with reference to FIG.

  The processing liquid supply apparatus is connected to a processing liquid storage container 1 (hereinafter referred to as a chemical liquid bottle 1) for storing a processing liquid L (resist liquid), and the chemical liquid bottle 1 via a gas supply pipe 6 to be connected to the chemical liquid bottle. An inert gas, for example, nitrogen (N2) gas supply source 71 (hereinafter referred to as N2 gas supply source 71), which is a pressurizing means for pressurizing the resist solution L in 1, and a first treatment liquid supply line 7a The buffer tank 2 is a temporary storage container that is connected to the chemical liquid bottle 1 and temporarily stores the processing liquid guided from the chemical liquid bottle 1, and the buffer tank 2 and the processing liquid supply nozzle 70a (hereinafter referred to as a supply nozzle 70a). ), A pump 3 that is provided on the buffer tank 2 side and supplies the processing liquid to the supply nozzle 70a in the second processing liquid supply pipe 7b, and in the processing liquid Mixed in A filter 4 to remove it are bubbles, and a closing valve AV and the suck-back valve SV is interposed adjacent to the secondary side of the filter 4.

  In this case, the open / close valve AV is formed by an electromagnetic open / close air operation valve such as an electropneumatic regulator, and the suck back valve SV is also formed electromagnetically. The on-off valve AV and suck back valve SV formed in this way are operated based on a control signal (trigger signal) from a controller 200 mainly composed of a central processing unit (CPU) as control means. It has become. The opening / closing operation of the opening / closing valve AV and the operation of the suck back valve SV are controlled in conjunction with the pump 3 that operates based on a control signal from the controller 200 as described later (FIGS. 6 and 6). 7). The open / close valve AV may be formed of an electromagnetic open / close valve combined with a speed controller, instead of an electromagnetic open / close air operation valve such as an electropneumatic regulator.

  In addition, for example, an electropneumatic regulator R, which is a pressure adjustment means that can be variably adjusted, is interposed in the gas supply line 6 that connects the chemical bottle 1 and the N 2 gas supply source 71. The electropneumatic regulator R includes an operation unit, for example, a proportional solenoid that operates in response to a control signal output from the controller 200, and a valve mechanism that opens and closes by the operation of the solenoid, and adjusts the pressure by opening and closing the valve mechanism. It is configured. An electromagnetic on-off valve V3 is interposed between the electropneumatic regulator R of the gas supply line 6 and the chemical bottle 1.

  On the other hand, on the exhaust pipe 8 connected to the upper part of the buffer tank 2 and on the drain pipe 9 connected to the upper part of the filter 4, open / close valves V1, V2 are respectively provided. An opening / closing operation is performed by a control signal output from the controller 200. The buffer tank 2 is provided with an upper limit liquid level sensor 5a and a lower limit liquid level sensor 5b for detecting the upper limit liquid level and the lower limit liquid level of the resist liquid L in the buffer tank 2, and these upper limit liquid level sensor 5a and A signal detected by the lower limit liquid level sensor 5b is transmitted to the controller 200.

  Next, the operation mode of the processing liquid supply apparatus will be described with reference to FIGS. 6 to 8 while comparing with the conventional processing liquid supply system. Conventionally, in order to supply (discharge) the resist solution L replenished from the chemical bottle 1 into the buffer tank 2 onto the wafer W from the supply nozzle 70a, as shown in FIG. The back valve SV operates in synchronization and supplies (discharges) a predetermined amount of resist solution L. In order to prevent dripping from the supply nozzle 70a when the supply (discharge) of the resist solution L is stopped, conventionally, the amount of lift of the valve body of the open / close valve AV is controlled to prevent dripping. At this time, the opening time and closing time of the opening / closing valve AV are usually 50 to 300 msec, while the setup time of the suck back valve SV is set to 300 to 1000 msec and the suck back time is set to 2000 msec. Thereby, the water hammer phenomenon (pressure pulsation) at the time of discharge of the pump 3 and when discharge is stopped is suppressed.

  However, there is a concern that only the closing operation control of the opening / closing valve AV is not sufficient to maintain the optimum liquid run-out state, that is, the optimum state before discharge in the next process, according to the characteristics (viscosity and surface tension) of different liquids. For example, when the characteristics of the resist solution are low viscosity and low surface tension, as shown in FIG. 10 (a), the liquid breakage position of the discharge port 72 of the supply nozzle 70a is lowered and the suck back adjustment is performed. As shown in FIG. 10B, the pulling is insufficient with respect to the optimum value (for example, 3 mm) of the suck back height H. Further, when the resist solution has a high viscosity and a high surface tension, as shown in FIG. 11 (a), the liquid breakage position of the discharge port 72 of the supply nozzle 70a becomes high, and the suck back adjustment is performed. As shown in FIG. 11 (b), the pulling is excessive with respect to the optimum value (for example, 3 mm) of the suck back height H. Here, the optimum value of the suck back valve height H means that the resist liquid L does not crystallize before discharge in the next process, and is smoothly discharged without delay at the time of discharge by the opening / closing operation of the opening / closing valve AV. A certain height position.

  In the embodiment of the present invention, when the characteristic of the resist solution L is low viscosity, for example, 10 cp or less, the suction setup operation of the suck back valve SV is superposed on the valve closing operation of the open / close valve AV. Specifically, as shown in FIG. 6, by setting the suction setup start time of the suck back valve SV at the start or before the start of the closing operation of the opening / closing valve AV, the liquid dripping with a low viscosity, for example, 10 cp or less. The resist solution L is easy to be removed when the valve is closed, the suck back height SV is controlled by the suction operation control of the suck back valve SV, and the optimum value (for example, 3 mm) at which the resist solution L does not crystallize before discharging in the next process. (See FIGS. 12A and 12B).

  In the embodiment of the present invention, when the characteristic of the resist solution L is high viscosity, for example, 80 cp or more, the suction stop operation of the suck back valve SV is superposed on the valve closing operation of the on-off valve AV. Specifically, as shown in FIG. 7, when the suction operation of the suck back valve SV is started before or during the start of the closing operation of the opening / closing valve AV, the liquid runs out with a high viscosity, for example, 80 cp or more. The internal behavior (pressure pulsation) of the resist liquid L that is difficult to increase is increased to improve the effect of running out of the liquid, and the suck back height H is controlled by the suction operation control of the suck back valve SV before discharging in the next process. The optimum value at which the resist solution L does not crystallize (for example, 3 mm)} can be set (see FIGS. 12A and 12B).

  In the embodiment described above, the suck back height H is the same when the characteristics (viscosity) of the resist liquid L are different. However, the suck back height H actually varies depending on the characteristics of the resist liquid L.

  In the above-described embodiment, the case where the processing liquid supply system according to the present invention is applied to the resist solution coating processing apparatus has been described. However, the processing liquid supply system according to the present invention is applied to a processing liquid other than the resist liquid, Is also applicable.

W Semiconductor wafer (substrate to be processed)
1 Chemical bottle (Processing liquid supply source)
3 Pumps 7a, 7b Treatment liquid supply pipe (treatment liquid supply flow path)
200 controller (control means)
AV Open / close valve SV Suck back valve L Resist liquid (treatment liquid)

Claims (3)

In a processing liquid supply system in which an opening / closing valve and a suck back valve are provided in a processing liquid supply channel connecting a processing liquid supply source and a processing liquid supply nozzle, the processing liquid supply is performed when the opening / closing valve is closed. A liquid runout control method for preventing dripping of the treatment liquid from the nozzle outlet,
The valve closing operation of the opening / closing valve and the suction operation of the suck back valve are performed based on different drive signals, and the suction operation of the suck back valve is performed with a treatment liquid to suppress internal pressure behavior when the opening / closing valve is closed A liquid runout control method in a treatment liquid supply system, characterized in that the control is performed in accordance with the characteristics of the open / close valve and the valve closing operation. In the liquid running out control method in the processing liquid supply system according to claim 1,
When the characteristic of the processing liquid is low viscosity, the suction setup operation of the suck back valve is controlled in superposition with the valve closing operation of the opening / closing valve. Control method. In the liquid running out control method in the processing liquid supply system according to claim 1,
In the processing liquid supply system, the suction start operation of the suck back valve is controlled in superposition with the closing operation of the opening / closing valve when the characteristic of the processing liquid is high viscosity. Control method.

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