JP2020155620A - Processing liquid supply device and control method therefor - Google Patents

Abstract

To provide a processing liquid supply device which enables appropriately closing an on-off valve in a short time with the suppression of a reduced life span of the on-off valve.SOLUTION: Drive pulses are continuously supplied to a stepping motor 20 at a switchover from an open state to a closed state of an on-off valve 10. When the stepping motor 20 rotates in response to the drive pulses, a valve body 12a moves toward a valve seat 11s. In response to the rotation of the stepping motor 20, a detection pulse is output from an encoder 50. When the stepping motor 20 stops to rotate, the supply of the drive pulses is stopped if a specific number k of continuous detection pulses are not output from the encoder 50. In the above state, the switchover of the on-off valve 10 from the open state to the closed state is completed.SELECTED DRAWING: Figure 2

Description

The present invention relates to a treatment liquid supply device for supplying a treatment liquid to a substrate and a control method for the treatment liquid supply device.

Conventionally, FPD (Flat Panel Display) substrates, semiconductor substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates used in liquid crystal display devices or organic EL (Electro Luminescence) display devices, etc. , A substrate processing apparatus is used to perform various processing on various substrates such as a ceramic substrate or a substrate for a solar cell.

In the substrate processing apparatus, for example, the processing liquid is supplied to the substrate from the processing liquid supply source through pipes and nozzles. An on-off valve is provided in the piping. The on-off valve can be switched between an open state in which the processing liquid is discharged from the nozzle and a closed state in which the processing liquid is not discharged from the nozzle.

Patent Document 1 describes an on-off valve control device for controlling the on-off valve. In the on-off valve control device, a position where the valve body of the on-off valve closes the flow path of the processing liquid is set as a closing position. The valve body is driven by the stepping motor based on the set closing position.

The appropriate closing position may change due to wear of various members constituting the on-off valve. Therefore, the origin (reference) of the closing position is set periodically and automatically. At this setting, first, a drive pulse for driving the valve body in the closing direction is given to the stepping motor. Next, after the step-out of the stepping motor is detected, a predetermined number of drive pulses for further driving the valve body in the closing direction are supplied to the stepping motor. After that, a predetermined number of drive pulses for driving the valve body in the opening direction are supplied to the stepping motor. In this way, the origin of the closing position of the valve body is searched, and the searched origin is set.

Japanese Unexamined Patent Publication No. 2004-348227

As described above, in the origin search method for the closed position described in Patent Document 1, a predetermined number of drive pulses are supplied to the stepping motor after the step-out occurs. At this time, if the current flowing through the stepping motor is large, a large torque is generated in the stepping motor, and the valve body is strongly pressed against the valve seat. Therefore, when the origin search of the closing position is frequently performed and a large deformation occurs in the contact portion between the valve body and the valve seat, the life of the on-off valve is shortened and particles are generated.

Further, in the above-mentioned origin search method, it takes a relatively long time to further move the valve body in the closing direction and the opening direction after the step-out is generated.

Further, the stepping motor rotates to a stable point where the torque acting on the rotor at the time of step-out is stable. However, this amount of rotation is not always a constant amount, and it is difficult to accurately grasp it. Therefore, it cannot be said that an appropriate closing position is always set only by operating the stepping motor with a predetermined number of drive pulses after the occurrence of step-out.

An object of the present invention is to provide a treatment liquid supply device and a control method for the treatment liquid supply device, which suppresses shortening of the life of the on-off valve and enables the on-off valve to be appropriately closed without requiring a long time. is there.

(1) The treatment liquid supply device according to the first invention is a treatment liquid supply device that supplies the treatment liquid to the substrate, and includes a treatment liquid flow path through which the treatment liquid to be supplied to the substrate flows, a valve seat, and a valve seat. An on-off valve including a valve body and provided in the processing liquid flow path, a stepping motor that switches the on-off valve between an open state and a closed state, a drive unit that supplies a drive pulse to the stepping motor, and a response to the rotation of the stepping motor. The on-off valve includes an encoder that outputs a detection pulse and a control unit that controls the drive unit based on the detection pulse output by the encoder, and the on-off valve is supplied by the drive unit when switching from the open state to the closed state. The valve body is configured to move toward the valve seat by rotating the stepping motor in response to the drive pulse, and the control unit is continuous with the stepping motor when the on-off valve is switched from the open state to the closed state. The drive unit is controlled so that the drive pulse is supplied, and when the encoder does not output a continuous specified number of detection pulses in response to the continuous drive pulse supply to the stepping motor, the drive pulse is supplied. Controls the drive unit so that is stopped.

In the processing liquid supply device, a drive pulse is continuously supplied to the stepping motor when the on-off valve is switched from the open state to the closed state. As a result, the stepping motor rotates in response to the drive pulse, so that the valve body moves toward the valve seat. At this time, a detection pulse is output from the encoder in response to the rotation of the stepping motor.

After that, when the reaction force acting from the valve seat to the valve body is balanced with the pressing force acting from the valve body to the valve seat while the valve body is in contact with the valve seat, the operation of the valve body is stopped and the stepping motor The rotation stops. Further, when the continuous specified number of detection pulses to be output from the encoder are no longer output, the supply of the drive pulse is stopped. As a result, the switching of the on-off valve from the open state to the closed state is completed, and the flow of the processing liquid in the processing liquid flow path is stopped.

In this case, by stopping the supply of the drive pulse within the range where the stepping motor does not step out, it is possible to prevent a large load from being generated inside the on-off valve when the on-off valve is switched from the open state to the closed state. The deformation inside the on-off valve is suppressed.

Further, according to the above operation, the valve body is appropriately positioned with respect to the valve seat in a state where the valve body moves in one direction toward the valve seat and stops. Therefore, it is not necessary to move the valve body in one direction and the opposite direction with respect to the valve seat in order to search for the position of the valve body to be positioned in the closed state.

Further, according to the above operation, since it is not necessary to step out the stepping motor, it is possible to prevent the valve body from being displaced with respect to the valve seat due to the stepping-out.

As a result, it is possible to suppress the shortening of the life of the on-off valve and to appropriately close the on-off valve without requiring a long time.

(2) In the control unit, the current value of the drive pulse supplied from the start of the movement of the valve body in the open state to the current switching time before the stop of the drive pulse supply is the drive pulse from the current switching time. The drive unit may be controlled so as to be larger than the current value of the drive pulse supplied by the time when the supply of the drive pulse is stopped.

In this case, the torque required for the movement of the valve body can be generated by increasing the current value of the drive pulse supplied from the start of the movement of the valve body to the time of switching the current. As a result, the occurrence of step-out due to the characteristics of the processing liquid flowing through the on-off valve and the frictional force generated during the operation of the valve body is prevented.

In addition, by reducing the current value of the drive pulse supplied from the time of current switching to the time of stopping the supply of the drive pulse, it is possible to prevent the pressing force acting on the valve seat from the valve body in the closed state from becoming excessively large. Will be done. As a result, it is possible to prevent large deformation of the contact portion between the valve body and the valve seat, and reduce the generation of particles from the contact portion.

(3) Even if the control unit determines the occurrence of an abnormality when the continuous drive pulse supply to the stepping motor is continued for a preset time when the on-off valve is switched from the open state to the closed state. Good.

In this case, it becomes possible to replace or maintain parts at an appropriate timing based on the determination of the occurrence of an abnormality.

(4) The control method of the treatment liquid supply device according to the second invention is a control method of the treatment liquid supply device for supplying the treatment liquid to the substrate, and the treatment liquid supply device is the treatment liquid to be supplied to the substrate. Supply a drive pulse to the processing liquid flow path, the valve seat and the valve body, the on-off valve provided in the processing liquid flow path, the stepping motor that switches the on-off valve between the open state and the closed state, and the stepping motor. The on-off valve includes a drive unit that operates and an encoder that outputs a detection pulse in response to the rotation of the stepping motor, and the on-off valve steps in response to the drive pulse supplied by the drive unit when switching from the open state to the closed state. The valve body is configured to move toward the valve seat as the motor rotates, and the control method is that a drive pulse is continuously supplied to the stepping motor when the on-off valve is switched from the open state to the closed state. When the step of controlling the drive unit and the continuous specified number of detection pulses are not output from the encoder in response to the supply of the continuous drive pulse to the stepping motor, the supply of the drive pulse is stopped. Including a step of controlling the drive unit.

In the control method of the processing liquid supply device, a drive pulse is continuously supplied to the stepping motor when the on-off valve is switched from the open state to the closed state. As a result, the stepping motor rotates in response to the drive pulse, so that the valve body moves toward the valve seat. At this time, a detection pulse is output from the encoder in response to the rotation of the stepping motor.

After that, when the reaction force acting from the valve seat to the valve body is balanced with the pressing force acting from the valve body to the valve seat while the valve body is in contact with the valve seat, the operation of the valve body is stopped and the stepping motor The rotation stops. Further, when the continuous specified number of detection pulses to be output from the encoder are no longer output, the supply of the drive pulse is stopped. As a result, the switching of the on-off valve from the open state to the closed state is completed, and the flow of the processing liquid in the processing liquid flow path is stopped.

In this case, by stopping the supply of the drive pulse within the range where the stepping motor does not step out, it is possible to prevent a large load from being generated inside the on-off valve when the on-off valve is switched from the open state to the closed state. The deformation inside the on-off valve is suppressed.

Further, according to the above operation, the valve body is appropriately positioned with respect to the valve seat in a state where the valve body moves in one direction toward the valve seat and stops. Therefore, it is not necessary to move the valve body in one direction and the opposite direction with respect to the valve seat in order to search for the position of the valve body to be positioned in the closed state.

Further, according to the above operation, since it is not necessary to step out the stepping motor, it is possible to prevent the valve body from being displaced with respect to the valve seat due to the stepping-out.

As a result, it is possible to suppress the shortening of the life of the on-off valve and to appropriately close the on-off valve without requiring a long time.

(5) In the control method of the processing liquid supply device, the current value of the drive pulse supplied from the start of the movement of the valve body in the open state to the current switching time before the stop of the drive pulse supply is the current. A step of controlling the drive unit so as to be larger than the current value of the drive pulse supplied from the time of switching to the time of stopping the supply of the drive pulse may be further included.

In this case, the torque required for the movement of the valve body can be generated by increasing the current value of the drive pulse supplied from the start of the movement of the valve body to the time of switching the current. As a result, the occurrence of step-out due to the characteristics of the processing liquid flowing through the on-off valve and the frictional force generated during the operation of the valve body is prevented.

In addition, by reducing the current value of the drive pulse supplied from the time of current switching to the time of stopping the supply of the drive pulse, it is possible to prevent the pressing force acting on the valve seat from the valve body in the closed state from becoming excessively large. Will be done. As a result, it is possible to prevent large deformation of the contact portion between the valve body and the valve seat, and reduce the generation of particles from the contact portion.

(6) The control method of the processing liquid supply device is that when the on-off valve is switched from the open state to the closed state, an abnormality occurs when the continuous drive pulse supply to the stepping motor is continued for a preset time. May further include a step of determining.

In this case, the on-off valve can be replaced or maintained at an appropriate timing based on the determination of abnormality.

According to the present invention, it is possible to suppress the shortening of the life of the on-off valve and to appropriately close the on-off valve without requiring a long time.

It is a schematic block diagram which shows the structure of the substrate processing apparatus which concerns on one Embodiment of this invention. It is a block diagram for demonstrating the structure of the processing liquid supply apparatus corresponding to the development unit of FIG. It is a figure which shows an example of the opening / closing operation in the on-off valve of FIG. It is a flowchart which shows an example of the opening / closing control processing of the on-off valve executed in the valve control part of FIG.

Hereinafter, the treatment liquid supply device and the control method of the treatment liquid supply device according to the embodiment of the present invention will be described with reference to the drawings. In the following description, the substrate is an FPD (Flat Panel Display) substrate, a semiconductor substrate, an optical disk substrate, a magnetic disk substrate, a magneto-optical disk, which is used in a liquid crystal display device, an organic EL (Electro Luminescence) display device, or the like. Refers to a substrate, a substrate for a photomask, a ceramic substrate, a substrate for a solar cell, or the like.

(1) Configuration of a Substrate Processing Device Equipped with a Processing Liquid Supply Device A substrate processing device including a processing liquid supply device will be described. FIG. 1 is a schematic block diagram showing a configuration of a substrate processing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the substrate processing device 100 is provided adjacent to the exposure device 500, and includes a coating processing unit 110, a development processing unit 120, a heat treatment unit 130, a transport unit 140, a control device 150, and a plurality of on-off valve devices. It includes V1 and V2.

The coating processing unit 110 includes a plurality of coating units SC. Each coating unit SC includes a spin chuck 91 and a discharge nozzle 92. The spin chuck 91 rotatably holds the untreated substrate W in a horizontal posture. The resist liquid is supplied to the discharge nozzle 92 from the coating liquid supply source 1 provided outside the substrate processing device 100 through the pipe p1. The discharge nozzle 92 discharges the supplied resist liquid onto the upper surface of the substrate W held by the spin chuck 91 (coating process). As a result, a resist film is formed on one surface of the untreated substrate W. The substrate W on which the resist film is formed is exposed by the exposure apparatus 500.

In the coating processing unit 110, an antireflection film may be formed on the substrate W. In this case, the heat treatment unit 130 may perform an adhesion strengthening treatment for improving the adhesion between the substrate W and the antireflection film. Further, in the coating processing unit 110, a resist cover film for protecting the resist film may be formed on the substrate W on which the resist film is formed.

The development processing unit 120 includes a plurality of development units SD. Each developing unit SD includes a spin chuck 93 and a discharge nozzle 94, similarly to the coating unit SC. The spin chuck 93 rotatably holds the substrate W after the exposure process by the exposure apparatus 500 in a horizontal posture. The developer is supplied to the discharge nozzle 94 from the developer supply source 2 provided outside the substrate processing device 100 through the pipe p2. The discharge nozzle 94 discharges the supplied developer liquid onto the upper surface of the substrate W held by the spin chuck 93 (development processing).

The heat treatment unit 130 heat-treats the substrate W before and after the coating treatment by each coating unit SC of the coating processing unit 110, the development processing by the developing processing unit 120, and the exposure processing by the exposure apparatus 500.

The transport unit 140 has a transport robot that transports the substrate W. The transfer robot of the transfer unit 140 transfers the substrate W between other transfer robots provided outside the substrate processing device 100, the coating processing unit 110, the development processing unit 120, the heat treatment unit 130, and the exposure apparatus 500.

The control device 150 includes, for example, a CPU and a memory, or a microcomputer, and controls the operations of the coating processing unit 110, the developing processing unit 120, the heat treatment unit 130, and the transport unit 140.

An on-off valve device V1 for switching between supply and stop of the resist liquid to the substrate W is provided in each of the plurality of pipes p1 connecting the plurality of coating units SC of the coating processing unit 110 and the coating liquid supply source 1. .. Further, an on-off valve device V2 for switching between supply and stop of the developer to the substrate W is provided in each of the plurality of pipes p2 connecting the plurality of development units SD of the development processing unit 120 and the developer supply source 2. ing. Each of the plurality of on-off valve devices V1 and V2 is controlled by the valve control unit 200 of the control device 150.

In the substrate processing device 100 of FIG. 1, the piping p1 provided corresponding to each coating unit SC, the on-off valve device V1, and the valve control unit 200 constitute a processing liquid supply device. Further, the piping p2 provided corresponding to each developing unit SD, the on-off valve device V2, and the valve control unit 200 constitute a processing liquid supply device.

(2) Specific Configuration and Operation of the Treatment Liquid Supply Device FIG. 2 is a block diagram for explaining the configuration of the treatment liquid supply device corresponding to the coating unit SC of FIG. 1. As shown in FIG. 2, the processing liquid supply device 300 includes a pipe p1, an on-off valve device V1, and a valve control unit 200.

The on-off valve device V1 includes an on-off valve 10, a stepping motor 20, a conversion mechanism 30, a drive unit 40, and an encoder 50. The on-off valve 10 has a valve box 11. An internal space is formed in the valve box 11. A part of the internal space is partitioned by the diaphragm 12 as a flow path space 11a forming a flow path of the treatment liquid (resist liquid in this example). Further, the valve box 11 is provided with an inflow port 11b and an outflow port 11c communicating with the flow path space 11a. The pipe p1 is connected to the inflow port 11b and the outflow port 11c.

The diaphragm 12 is made of, for example, a fluororesin or rubber. The central portion of the diaphragm 12 functions as a valve body 12a. Inside the valve box 11, a valve seat 11s is formed so as to face the valve body 12a with the flow path space 11a interposed therebetween. The valve seat 11s has an opening 11o for guiding the treatment liquid (resist liquid in this example) in the flow path space 11a to the outflow port 11c. The opening and closing of the opening 11o is possible by moving the valve body 12a in one direction or the opposite direction with respect to the valve seat 11s. Hereinafter, the direction in which the valve body 12a approaches from the position away from the valve seat 11s toward the valve seat 11s is referred to as a closing direction, and the opposite direction is referred to as an opening direction. A valve rod 13 is further provided inside the valve box 11. The valve rod 13 is connected to the valve body 12a and extends in the opening direction from the valve body 12a.

The stepping motor 20 of this example is, for example, a two-phase type stepping motor, and is used as a power source for switching the open / closed state of the on-off valve 10 by moving the valve body 12a by the valve rod 13. As the stepping motor 20, a three-phase type or five-phase type stepping motor may be used.

The conversion mechanism 30 includes, for example, a rack and pinion mechanism, and converts the rotational force generated in the stepping motor 20 into a force for moving the valve stem 13 in the closing direction or the opening direction. Further, the conversion mechanism 30 converts the force acting on the valve stem 13 in the closing direction or the opening direction into a force for rotating the rotation axis of the stepping motor 20 in one direction or the opposite direction.

The drive unit 40 is connected to a DC power supply (not shown) and supplies drive pulses to the stepping motor 20 based on the control of the valve control unit 200, which will be described later. As a result, the stepping motor 20 rotates in an angle fractional direction or vice versa according to the number of supplied drive pulses.

The encoder 50 is a rotary encoder, detects the amount of rotation of the rotor (not shown) of the stepping motor 20, and outputs a pulse signal (hereinafter, referred to as a detection pulse) as the detection signal. For example, when one drive pulse is supplied to the stepping motor 20 and the stepping motor 20 rotates by an angle corresponding to the drive pulse, the encoder 50 outputs one detection pulse. On the other hand, even if one drive pulse is supplied to the stepping motor 20, if the stepping motor 20 does not rotate, the encoder 50 does not output the detection pulse.

The valve control unit 200 includes an abnormality determination unit 210, a switching determination unit 220, a pulse control unit 230, a current adjustment unit 240, and a setting storage unit 250. These functional units are realized, for example, by the CPU of the control device 150 of FIG. 1 executing a computer program stored in the memory. In addition, a part or all of the above-mentioned configurations may be realized by hardware such as an electronic circuit.

The operation of each functional unit of the valve control unit 200 will be described together with the opening / closing operation of the on-off valve 10. FIG. 3 is a diagram showing an example of an opening / closing operation of the on-off valve 10 of FIG. The change over time in the position of the valve body 12a is shown graphically in the upper part of FIG. In the upper graph of FIG. 3, the vertical axis represents the relative position of the valve body 12a with respect to the valve seat 11s, and the horizontal axis represents time. On the vertical axis, advancing in the direction of the arrow means that the valve body 12a moves in the opening direction, and advancing in the direction opposite to the direction of the arrow means that the valve body 12a moves in the closing direction. In the lower part of FIG. 3, the state inside the on-off valve 10 at a plurality of time points t0 to t5 shown in the upper graph is shown in a schematic cross-sectional view.

In this example, it is assumed that the on-off valve 10 is in the closed state in the initial state at the time point t0. The initial position of the valve body 12a at this time is indicated by the symbol pp. The valve control unit 200 is instructed to switch the on-off valve 10 from the closed state to the open state when the supply of the resist liquid to the substrate W in the coating unit SC of FIG. 1 is started. Further, when the supply of the resist liquid to the substrate W in the coating unit SC is stopped, the on-off valve 10 is instructed to switch from the open state to the closed state.

The setting storage unit 250 of FIG. 2 stores a preset number of drive pulses (hereinafter, referred to as open pulse number) m for switching the on-off valve 10 from the closed state to the open state. The number of open pulses m is, for example, 400. Further, the setting storage unit 250 stores a first current value of a drive pulse preset for switching the on-off valve 10 from the closed state to the open state. The first current value is set so that the stepping motor 20 does not step out in consideration of the characteristics of the processing liquid (resist liquid in this example) flowing through the on-off valve 10 and the frictional force generated when the valve body 12a moves. It is set to a relatively large value, for example 0.2 (A).

When the switching from the closed state to the open state of the on-off valve 10 is commanded at the time point t0 in FIG. 3, the pulse control unit 230 sends a drive pulse for moving the valve body 12a in the open direction to the stepping motor 20 by the number of open pulses m. The drive unit 40 is controlled so as to supply continuously. Further, the current adjusting unit 240 controls the driving unit 40 so that the current value of the driving pulse becomes the first current value.

As a result, the valve body 12a moves from the initial position pp to the position pa corresponding to the open state of the on-off valve 10 from the time point t0 to the time point t1. As a result, the resist liquid flows through the pipe p1 through the on-off valve 10.

The setting storage unit 250 stores a preset number of drive pulses (hereinafter referred to as the number of closed pulses) n for switching the current value of the drive pulse when the on-off valve 10 is switched from the open state to the closed state. Has been done. The number of closed pulses n is the number of open pulses m or less. The subtraction value (difference) of the number of closed pulses n with respect to the number of open pulses m is preferably 0 or more and 1/2 or less of the number of open pulses m, and preferably 0 or more and 10 or less. When the number of open pulses m is 400, the number of closed pulses n may be, for example, 398.

Further, the setting storage unit 250 stores the second and third current values of the drive pulse set in advance for switching the on-off valve 10 from the closed state to the open state. The second current value corresponds to the drive pulse having the number of closed pulses n, and is set to a relatively large value so as not to cause step-out in the stepping motor 20 like the first current value, for example, 0.2 ( A). The second current value may be equal to the first current value. On the other hand, the third current value is set to a value lower than the first and second current values so that the pressing force acting on the valve seat 11s from the valve body 12a when the on-off valve 10 is closed does not become excessively large. For example, 0.07 (A).

When the switching from the open state to the closed state of the on-off valve 10 is commanded at the time point t2, the pulse control unit 230 continuously sends a drive pulse for moving the valve body 12a in the closing direction to the stepping motor 20 by the number of closed pulses n. The drive unit 40 is controlled so as to supply. Further, the current adjusting unit 240 controls the driving unit 40 so that the current value of the driving pulse becomes the second current value while the driving pulse having the number of closed pulses n is supplied to the stepping motor 20.

As a result, when the number of closed pulses n is smaller than the number of open pulses m, the valve body 12a moves from the time point t2 to the time point t3 to the position bp deviated by a certain distance in the opening direction from the position pp.

After the time point t3, the current adjusting unit 240 controls the driving unit 40 so that the current value of the driving pulse becomes the third current value until the on-off valve 10 is closed.

When the stepping motor 20 is driven by the third current value, when the reaction force acting on the valve body 12a from the valve seat 11s is balanced with the pressing force acting on the valve seat 11s from the valve body 12a, the valve body 12a Is stopped moving in the closing direction. As a result, even when the drive pulse is supplied from the drive unit 40 to the stepping motor 20, the detection pulse is not output from the encoder 50.

In the setting storage unit 250, a preset number k for determining the completion of switching from the open state to the closed state of the on-off valve 10 is stored as a predetermined number. The switching determination unit 220 monitors the control state of the drive unit 40 by the pulse control unit 230, and also monitors the detection pulse output from the stepping motor 20. As a result of these monitoring, the switching determination unit 220 switches the on-off valve 10 to the closed state when the encoder 50 does not output a continuous detection pulse of a specified number of k in response to the supply of the continuous drive pulse. Determine that it is complete.

When the switching determination unit 220 determines that the on-off valve 10 has been switched to the closed state, the pulse control unit 230 stops the supply of the drive pulse from the drive unit 40 to the stepping motor 20.

Here, when the valve body 12a is stopped with respect to the rotation of the stepping motor 20 and a predetermined number of drive pulses are further supplied to the stepping motor 20 so that the valve body 12a moves in the closing direction, the stepping motor 20 Steps out. When the stepping motor 20 is stepped out, the position of the valve body 12a fluctuates. It is difficult to grasp this amount of fluctuation. Therefore, the above-mentioned specified number k is set so as not to cause step-out of the stepping motor 20, and is 2 in this example.

In the example of FIG. 3, from the time point t3 to the time point t4, the valve body 12a moves in the closing direction in response to the supply of the drive pulse, but the movement stops at the time point t4. After that, at the time point t5, it is determined that the on-off valve 10 has been switched to the closed state.

When the switching of the on-off valve 10 to the closed state is completed as described above, the rotation angle of the stepping motor 20 is maintained and the position of the valve body 12a is fixed. In the example of FIG. 3, the valve body 12a is fixed at a position pc slightly deviated from the initial position pp in the closing direction. This means that the position of the valve body 12a when the on-off valve 10 is in the closed state has been changed to a more appropriate position pc than the position pp at the time point t0. As a result, in the on-off valve 10, the flow of the treatment liquid (resist liquid in this example) in the pipe p1 is appropriately blocked.

During a series of operations when the on-off valve 10 is switched to the closed state, an abnormality occurs in any of the on-off valve 10, the stepping motor 20, and the encoder 50, so that the on-off valve 10 is accurately switched to the closed state. It may not be possible to judge.

For example, in the encoder 50, if it is not determined that the on-off valve 10 has been switched to the closed state due to continuous generation of noise having a waveform similar to the detection pulse, the supply of the drive pulse to the stepping motor 20 is stopped. Not done. In this case, step-out occurs in the stepping motor 20. Alternatively, when the valve body 12a is detached from the valve rod 13, the valve rod 13 moves beyond the position where it should be stopped and collides with the valve seat 11s.

Therefore, the abnormality determination unit 210 determines the occurrence of an abnormality when the continuous drive pulse supply is continued for a predetermined time when the on-off valve 10 is switched from the open state to the closed state. In the example of FIG. 3, the abnormality determination unit 210 determines the occurrence of an abnormality, for example, when the supply of continuous drive pulses is continued for a predetermined time beyond a predetermined time from the time point t3. Further, the abnormality determination unit 210 outputs the determination result. In this case, it becomes possible to replace or maintain parts at an appropriate timing based on the determination of the occurrence of an abnormality.

The processing liquid supply device 300 may be provided with a presentation device (display device, voice output device, or the like) that presents the abnormality determination result output from the abnormality determination unit 210 to the user. In this case, the user can easily grasp the occurrence of an abnormality in the on-off valve device V2.

The processing liquid supply device corresponding to the developing unit SD of FIG. 1 has basically the same configuration and operation as the processing liquid supply device 300 of FIGS. 3 and 4.

(3) Opening / Closing Control Process of On-off Valve 10 FIG. 4 is a flowchart showing an example of an opening / closing control process of the on-off valve 10 executed by the valve control unit 200 of FIG. The opening / closing control process is started when the valve control unit 200 is instructed to switch the opening / closing state of the on-off valve 10. In the following description, it is assumed that the valve control unit 200 has a built-in counter. Further, it is assumed that the valve control unit 200 has a built-in timer.

First, the pulse control unit 230 determines whether or not the command given at the start is a command for switching the on-off valve 10 from the open state to the closed state (step S11).

When the command at the start is a command for switching from the open state to the closed state, the pulse control unit 230 and the current adjustment unit 240 continuously send the drive pulse having the number of closed pulses n to the stepping motor 20 at the second current value. The drive unit 40 is controlled so as to be supplied (step S12). At this time, the drive pulse supplied to the stepping motor 20 corresponds to the movement of the valve body 12a in the closing direction. As a result, the valve body 12a moves in the closing direction with a relatively high torque. Further, the switching determination unit 220 resets the value of the counter and resets the timer, and starts the time measurement by the timer (step S13).

Next, the abnormality determination unit 210 determines whether or not a predetermined predetermined time has elapsed from the start of time measurement by the timer (step S14). When a predetermined predetermined time has not elapsed from the start of time measurement by the timer, the pulse control unit 230 and the current adjustment unit 240 are set so that one drive pulse is supplied to the stepping motor 20 at a third current value. In addition, the drive unit 40 is controlled (step S15). At this time, the drive pulse supplied to the stepping motor 20 corresponds to the movement of the valve body 12a in the closing direction.

Next, the switching determination unit 220 determines whether or not the detection pulse is output from the encoder 50 in response to the drive pulse supplied in step S15 (step S16). When the detection pulse is output, the process is returned from step S12 to step S14. On the other hand, when the detection pulse is not output, the switching determination unit 220 increments the counter value (step S17). Further, the switching determination unit 220 determines whether or not the detection pulse is not output for a specified number of k consecutive times based on the value of the counter (step S18).

If the fact that the detection pulse is not output is not continuous for a specified number of k, the process is returned from step S18 to step S14. On the other hand, when the detection pulse is not output continuously for a specified number of k, the open / close control process ends in a state where the supply of the drive pulse to the stepping motor 20 is stopped.

In step S11 above, when the command at the start is a command to switch to the open state, the pulse control unit 230 continuously supplies a drive pulse having an open pulse number of m to the stepping motor 20 at the first current value. As described above, the drive unit 40 is controlled (step S19). At this time, the drive pulse supplied to the stepping motor 20 corresponds to the movement of the valve body 12a in the opening direction. As a result, the valve body 12a moves in the opening direction with a relatively high torque. After that, the open / close control process ends.

In step S14 above, when a predetermined predetermined time has elapsed from the start of time measurement by the timer, the abnormality determination unit 210 determines the occurrence of an abnormality and outputs the determination result to the outside of the valve control unit 200. (Step S20). After that, the open / close control process ends.

(4) Effect (a) In the above-mentioned processing liquid supply device 300, a drive pulse is continuously supplied to the stepping motor 20 when the on-off valve 10 is switched from the open state to the closed state. As the stepping motor 20 rotates in response to the drive pulse, the valve body 12a moves toward the valve seat 11s. At this time, a detection pulse is output from the encoder 50 in response to the rotation of the stepping motor 20.

When the reaction force acting on the valve body 12a from the valve seat 11s is balanced with the pressing force acting on the valve seat 11s from the valve body 12a in the state where the valve body 12a is in contact with the valve seat 11s, the valve body 12a is closed. The movement of the stepping motor 20 is stopped, and the rotation of the stepping motor 20 is stopped. Next, when the continuous specified number of detection pulses k to be output from the encoder 50 are no longer output, the supply of the drive pulse is stopped. As a result, the switching of the on-off valve 10 from the open state to the closed state is completed, and the flow of the processing liquid in the pipes p1 and p2 is stopped.

In this case, by stopping the supply of the drive pulse within the range where the stepping motor 20 does not step out, it is possible to prevent a large load from being generated inside the on-off valve 10 when the on-off valve 10 is switched between open and closed states. To. As a result, deformation inside the on-off valve 10 is suppressed.

Further, according to the above operation, the valve body 12a is appropriately positioned with respect to the valve seat 11s in a state where the valve body 12a moves in the closing direction and stops. Therefore, it is not necessary to move the valve body 12a in the opening direction and the closing direction with respect to the valve seat 11s in order to search for the position of the valve body 12a to be positioned in the closed state.

Further, according to the above operation, since it is not necessary to step out the stepping motor 20, it is possible to prevent the valve body 12a from being displaced with respect to the valve seat 11s due to the stepping-out.

As a result, it is possible to suppress the shortening of the life of the on-off valve 10 and to appropriately close the on-off valve 10 without requiring a long time.

(B) In the above-mentioned processing liquid supply device 300, when the on-off valve 10 is switched from the open state to the closed state, the stepping motor 20 is second while the drive pulse having the number of closed pulses n is supplied to the stepping motor 20. It is driven by the current value of. As a result, the occurrence of step-out due to the characteristics of the processing liquid flowing through the on-off valve and the frictional force generated during the operation of the valve body 12a is prevented.

After that, the current value of the drive pulse supplied to the stepping motor 20 is changed to the third current value until the supply of the drive pulse is stopped. In this case, it is suppressed that the pressing force acting on the valve seat 11s from the valve body 12a in the closed state becomes excessively large. As a result, it is possible to prevent large deformation of the contact portion between the valve body 12a and the valve seat 11s, and reduce the generation of particles from the contact portion.

(5) Other Embodiments (a) In the above-described embodiment, the on-off valve 10 in the processing liquid supply device 300 is used to switch between supplying and stopping the processing liquid (resist liquid, developing liquid, etc.) to the substrate W. The open / closed state of the above is switched, but the present invention is not limited to this.

A command for switching the open / closed state of the on-off valve 10 may be given to the valve control unit 200 by the user operating an operation unit of the substrate processing device 100 (not shown). In this case, the user can instruct the switching operation of the on-off valve 10 similar to the example of FIG. 3 for the units (coating unit SC and developing unit SD in the above example) that supply the processing liquid to the substrate W. ..

Further, as shown in FIG. 3, a series of operations for sequentially switching the on-off valve 10 in the closed state between the open state and the closed state may be automatically performed at a fixed cycle or every predetermined number of lots. Alternatively, it may be automatically performed as an initialization operation of each unit (coating unit SC and developing unit SD in the above example) when the power of the substrate processing apparatus 100 is turned on.

(B) In the above embodiment, the treatment liquid supply device is applied to the resist liquid supply system that supplies the resist liquid to the substrate W and the developer supply system that supplies the developer liquid to the substrate W, respectively. Not limited to this.

The treatment liquid supply device according to the present invention can be applied to a coating liquid supply system that supplies various coating liquids for forming an antireflection film, a resist cover film, or the like on a substrate W. Alternatively, the treatment liquid supply device according to the present invention can also be applied to a cleaning liquid supply system that supplies a cleaning liquid such as pure water or a chemical liquid to the substrate W.

(C) In the above embodiment, the rotary encoder is used as the encoder 50 for detecting the rotation of the stepping motor 20, but the present invention is not limited thereto. The encoder 50 may be a linear encoder that detects the movement of the valve stem 13 in the opening direction and the closing direction. In this case, the movement of the valve stem 13 in the opening direction and the closing direction detected by the linear encoder can be detected as the rotation of the stepping motor 20.

(D) In the above embodiment, the current value of the drive pulse supplied to the stepping motor 20 when the on-off valve 10 is switched from the open state to the closed state is changed in two stages, but the present invention is limited to this. Not done. The current value of the drive pulse supplied to the stepping motor 20 when the on-off valve 10 is switched from the open state to the closed state may be constant. When the torque required to move the valve stem 13 is sufficiently small due to the low viscosity of the treatment liquid or the small frictional force generated during the operation of the valve stem 13, the current value is the above-mentioned third. It is desirable to set the current value of.

(6) Correspondence relationship between each component of the claim and each element of the embodiment The example of correspondence between each component of the claim and each element of the embodiment will be described below. In the above embodiment, the resist solution and the developing solution are examples of the processing solution, the pipes p1 and p2 are examples of the processing solution flow path, the valve control unit 200 is an example of the control unit, and the number of closed pulses is n. The time point when all the drive pulses are supplied to the stepping motor 20 (time point t3 in FIG. 3) is an example of the current switching time point.

As each component of the claim, various other components having the structure or function described in the claim can also be used.

1 ... Coating liquid supply source, 2 ... Developer liquid supply source, 10 ... On-off valve, 11 ... Valve box, 11a ... Flow path space, 11b ... Inflow port, 11c ... Outflow port, 11o ... Opening, 11s ... Valve seat, 12 ... Diaphragm, 12a ... Valve body, 13 ... Valve rod, 20 ... Stepping motor, 30 ... Conversion mechanism, 40 ... Drive unit, 50 ... Encoder, 91, 93 ... Spin chuck, 92, 94 ... Discharge nozzle, 100 ... Substrate processing Equipment, 110 ... Coating processing unit, 120 ... Development processing unit, 130 ... Heat treatment unit, 140 ... Conveying unit, 150 ... Control device, 200 ... Valve control unit, 210 ... Abnormality determination unit, 220 ... Switching determination unit, 230 ... Pulse Control unit, 240 ... current adjustment unit, 250 ... setting storage unit, 300 ... processing liquid supply device, 500 ... exposure device, SC ... coating unit, SD ... development unit, V1, V2 ... on-off valve device, W ... substrate, p1 , P2 ... Piping

Claims (6)

A processing liquid supply device that supplies the processing liquid to the substrate.
A processing liquid flow path through which the processing liquid to be supplied to the substrate flows, and
An on-off valve provided in the processing liquid flow path, including a valve seat and a valve body,
A stepping motor that switches the on-off valve between the open state and the closed state,
A drive unit that supplies drive pulses to the stepping motor,
An encoder that outputs a detection pulse in response to the rotation of the stepping motor,
Including a control unit that controls the drive unit based on a detection pulse output by the encoder.
When the on-off valve is switched from the open state to the closed state, the stepping motor rotates in response to the drive pulse supplied by the drive unit, so that the valve body moves toward the valve seat. Configured to move,
The control unit controls the drive unit so that the drive pulse is continuously supplied to the stepping motor when the on-off valve is switched from the open state to the closed state, and continuously to the stepping motor. A processing liquid supply device that controls the drive unit so that the supply of the drive pulse is stopped when a predetermined number of continuous detection pulses are not output from the encoder in response to the supply of the drive pulse. In the control unit, the current value of the drive pulse supplied from the start of the movement of the valve body in the open state to the current switching time before the stop of the supply of the drive pulse is the current switching time. The processing liquid supply device according to claim 1, wherein the drive unit is controlled so as to be larger than the current value of the drive pulse supplied from the drive pulse to the time when the supply of the drive pulse is stopped. The control unit determines the occurrence of an abnormality when the continuous supply of the drive pulse to the stepping motor is continued for a preset time when the on-off valve is switched from the open state to the closed state. The treatment liquid supply device according to claim 1 or 2. It is a control method of a processing liquid supply device that supplies a processing liquid to a substrate.
The treatment liquid supply device is
A processing liquid flow path through which the processing liquid to be supplied to the substrate flows, and
An on-off valve provided in the processing liquid flow path, including a valve seat and a valve body,
A stepping motor that switches the on-off valve between the open state and the closed state,
A drive unit that supplies drive pulses to the stepping motor,
Including an encoder that outputs a detection pulse in response to the rotation of the stepping motor.
When the on-off valve is switched from the open state to the closed state, the stepping motor rotates in response to the drive pulse supplied by the drive unit, so that the valve body moves toward the valve seat. Configured to move,
The control method is
A step of controlling the drive unit so that the drive pulse is continuously supplied to the stepping motor when the on-off valve is switched from the open state to the closed state.
The drive unit is controlled so that the supply of the drive pulse is stopped when a specified number of continuous detection pulses are not output from the encoder in response to the continuous supply of the drive pulse to the stepping motor. A method of controlling a treatment fluid supply device, including steps. The current value of the drive pulse supplied from the start of the movement of the valve body in the open state to the current switching time before the stop of the supply of the drive pulse is the current value of the drive pulse from the current switching time. The method for controlling a processing liquid supply device according to claim 4, further comprising a step of controlling the drive unit so as to be larger than the current value of the drive pulse supplied by the time when the supply is stopped. Further including a step of determining the occurrence of an abnormality when the continuous supply of the drive pulse to the stepping motor is continued for a preset time when the on-off valve is switched from the open state to the closed state. , The control method of the treatment liquid supply device according to claim 4 or 5.

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