Patent Publication Number: US-2018046083-A1

Title: Processing liquid supplying apparatus and method of controlling processing liquid supplying apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a processing liquid supplying apparatus and a method of controlling the processing liquid supplying apparatus that supplies a processing liquid to substrates such as semiconductor substrates, glass substrates for liquid crystal display, glass substrates for photomask, and optical disk substrates. 
     BACKGROUND ART 
     As illustrated in  FIG. 8 , a current 1 y-used processing liquid supplying apparatus includes a dispensing nozzle  111  that dispenses a developer as a processing liquid, a developer supplying source  113 , and a pipe  115  that feeds the developer from the developer supplying source  113  to the dispensing nozzle  111 . A pump P and an on-off valve  117  are interposingly arranged on the pipe  115 . 
     The on-off valve  117  allows flow regulation, and operates by taking in and out gas with a gas supplying unit  147 . Moreover, an operator rotates a flow regulating handle  118  of the on-off valve  117  to cause a desired flow rate of developer to pass while the on-off valve  117  is on (i.e., in an opened condition). 
     When a photoresist is supplied as the processing liquid, the current 1 y-used processing liquid supplying apparatus includes a suck back valve disposed between the dispensing nozzle  111  and the on-off valve  117 . See, for example, Patent Literature 1. 
     Patent Literature 1: Japanese Patent No. 5442232B 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the case of supplying not only the photoresist but also the developer, it is desired to prevent drips of the developer onto the substrate. In addition, the flow of the developer is regulated by rotating the flow regulating handle  118  with an operator&#39;s sense, leading to difficulty in flow regulation. Accordingly, it is desired to facilitate the flow regulation of the processing liquid. Moreover, if a large flow rate of developer passes through the pipe, a water hammer as an impact caused by closing the flow path by the on-off valve causes the developer to be interrupted, and thus the developer drips. Then, it is desired to prevent the drips certainly. 
     The present invention has been made regarding the state of the art noted above, and its primary object is to provide a processing liquid supplying apparatus and a method of controlling the processing liquid supplying apparatus that allows prevention of drips of a processing liquid and flow regulation of the processing liquid with a rational configuration. Another secondary object is to provide a processing liquid supplying apparatus and a method of controlling the processing liquid supplying apparatus that allows certain prevention of the drips. 
     Solution to Problem 
     The present invention is constituted as stated below to achieve the above object. One aspect of the present invention provides a processing liquid supplying apparatus, the apparatus including a processing liquid flow path that passes a processing liquid, an on-off valve that opens/closes the processing liquid flow path, a valve element disposed downstream of the on-off valve for adjusting an aperture of the processing liquid flow path, a volume variation unit disposed downstream of the on-off valve for cooperating with the valve element to vary a volume of a downstream processing liquid flow path disposed downstream of the on-off valve, a valve element drive unit that drives the valve element, and a controller that causes the valve element drive unit to move the volume variation unit cooperating with the valve element for increasing the volume of the downstream processing liquid flow path when the on-off valve closes the processing liquid flow path, and causes the valve element drive unit to move the valve element for regulating a flow rate of the processing liquid when the on-off valve opens the processing liquid flow path. 
     With the processing liquid supplying apparatus according to the aspect of the present invention, disposed downstream of the on-off valve that opens/closes the processing liquid flow path are the valve element that adjust the aperture of the processing liquid flow path, and the volume variation unit that cooperates with the valve element to vary the volume of the downstream processing liquid flow path disposed downstream of the on-off valve. The valve element is driven by the valve element drive unit. The controller causes the valve element to move the volume variation unit cooperating with by the valve element drive unit for increasing the volume of the downstream processing liquid flow path when the on-off valve closes the processing liquid flow path. This allows suck back and prevention of drips of the processing liquid. Moreover, the controller causes the valve element drive unit to move the valve element for regulating the flow rate of the processing liquid when the on-off valve opens the processing liquid flow path. Accordingly, this allows the valve element drive unit to perform the flow regulation of the processing liquid readily that is current 1 y controlled with an operator&#39;s sense. Moreover, since prevention of the drips of the processing liquid as well as the flow regulation of the processing liquid are performable with the same valve element drive unit, the needless configuration is omittable to achieve space saving compared to the configuration in which the valve element drive unit is provided individually. This allows supply of the processing liquid at different flow rates to every substrate, and the flow rate of the processing liquid is variable to the same substrate in the course of the supply. 
     Moreover, it is preferred that the valve element drive unit of the processing liquid supplying apparatus is a motor. The motor as the valve element drive unit allows easy suck back at plural times, i.e., in multiple stages. This also achieves ready variation in valve element position for the flow regulation. 
     It is also preferred that the controller of the processing liquid supplying apparatus causes the valve element drive unit to move the valve element to a suck back reference position for decreasing the flow rate of the processing liquid, and then causes the on-off valve to close the processing liquid flow path and causes the valve element drive unit to move the volume variation unit cooperating with the valve element for increasing the volume of the processing liquid flow path. This decreases the flow rate of the processing liquid when the on-off valve closes the processing liquid flow path, leading to prevention of drips of the processing liquid caused by the increased flow rate of the processing liquid. That is, this certainly allows prevention of the drips. 
     Moreover, it is preferred that the controller of the processing liquid supplying apparatus causes the valve element drive unit to move the valve element from a position of the valve element with the increased volume of the downstream processing liquid flow path to a position where the flow rate is changed to a preset flow rate and causes the on-off valve to open the processing liquid flow path. Although the position of the valve element is shifted by the suck back, the preset flow rate of the processing liquid is able to be supplied upon opening of the processing liquid flow path with the on-off valve. 
     In the aspect of the processing liquid supplying apparatus, the valve element is moved upward to the position where the flow rate is changed to the preset flow rate when the on-off valve opens the processing liquid flow path. Since the valve element is moved upward for the preset flow rate upon the opening of the processing liquid flow path with the on-off valve, no processing liquid is pushed out and further suck back is performed. This avoids liquid drips. 
     In the aspect of the processing liquid supplying apparatus, a lowering speed of the valve element is changed in such a manner that the flow rate is changed to the preset flow rate when the valve element drive unit causes the valve element to move downwardly to the position where the flow rate is changed to the preset flow rate. For instance, the lowering speed of the valve element is changed such that the dispensing nozzle dispenses the processing liquid at the preset flow rate when the valve element is moved downward to a position where the flow rate is changed to the preset flow rate. This allows the flow rate of the processing liquid dispensed by the movement of the valve element to approach to a flow rate at which the on-off valve opens the processing liquid flow path. 
     It is also preferred that the processing liquid flow path of the processing liquid supplying apparatus is formed by a single part. This achieves integration of the on-off valve and the suck back valve with a flow rate regulation function, leading to a simplified configuration. 
     Moreover, the processing liquid supplying apparatus according to the aspect further includes a dispensing nozzle disposed downstream of the valve element, the dispensing nozzle being connected to the processing liquid flow path via a pipe for dispensing the processing liquid. This allows suction of the processing liquid within the dispensing nozzle and flow regulation of the processing liquid dispensed from the dispensing nozzle. 
     Moreover, in the processing liquid supplying apparatus according to the aspect, the processing liquid is a developer. This avoids drips of the developer, leading to flow regulation of the developer. 
     Moreover, in the processing liquid supplying apparatus according to the aspect, the controller causes the valve element drive unit to reciprocate the volume variation unit cooperating with the valve element when the on-off valve closes the processing liquid flow path. For instance, a tip of the dispensing nozzle for dispensing the developer as the processing liquid is immersed into deionized water for sucking the deionized water, holding the sucked deionized water for a certain period of time, or pushing out the sucked deionized water, whereby the tip end of the dispensing nozzle is cleaned. 
     Another aspect of the present invention provides a method of controlling a processing liquid supplying apparatus including a processing liquid flow path that passes a processing liquid, an on-off valve that opens/closes the processing liquid flow path, a valve element disposed downstream of the on-off valve for adjusting an aperture of the processing liquid flow path, a volume variation unit disposed downstream of the on-off valve for varying a volume of a downstream processing liquid flow path disposed downstream of the on-off valve, and a valve element drive unit that drives the valve element. The method includes a step of increasing the volume of the downstream processing liquid flow path by causing the valve element drive unit to move the volume variation unit cooperating with the valve element when the on-off valve closes the processing liquid flow path, and a step of regulating a flow rate of the processing liquid by causing the valve element drive unit to move the valve element when the on-off valve opens the processing liquid flow path. 
     According to the processing liquid supplying apparatus according to the other aspect of present invention, downstream of the on-off valve that opens/closes the processing liquid flow path, provided are the valve element that adjusts the aperture of the processing liquid flow path, and the volume variation unit that cooperates with the valve element for varying the volume of the downstream processing liquid flow path disposed downstream of the on-off valve. The valve element drive unit drives the valve element. Such control achieves the increased volume of the downstream processing liquid flow path by causing the valve element drive unit to move the volume variation unit cooperating with the valve element when the on-off valve closes the processing liquid flow path. Accordingly, this allows suck back, leading to prevention of drips of the processing liquid. In addition, the control obtains the regulated flow rate of the processing liquid by causing the valve element drive unit to move the valve element when the on-off valve opens the processing liquid flow path. This facilitates the flow regulation of the processing liquid by the valve element drive unit which is current 1 y made by the operator&#39;s sense. Moreover, since prevention of the drips of the processing liquid as well as the flow regulation of the processing liquid are performable with the same valve element drive unit, the needless configuration is omittable to achieve space saving compared to the configuration in which the valve element drive unit is provided individually. This allows supply of the processing liquid at different flow rates to every substrate, and the flow rate of the processing liquid is variable to the same substrate in the course of the supply. 
     Advantageous Effects of Invention 
     According to the processing liquid supplying apparatus and the method of controlling the processing liquid supplying apparatus according to the aspects of present invention, downstream of the on-off valve that opens/closes the processing liquid flow path, provided are the valve element that adjusts the aperture of the processing liquid flow path, and the volume variation unit that cooperates with the valve element for varying the volume of the downstream processing liquid flow path disposed downstream of the on-off valve. The valve element drive unit drives the valve element. Such control achieves the increased volume of the downstream processing liquid flow path by causing the valve element drive unit to move the volume variation unit cooperating with the valve element when the on-off valve closes the processing liquid flow path. Accordingly, this allows suck back, leading to prevention of drips of the processing liquid. In addition, the control obtains the regulated flow rate of the processing liquid by causing the valve element drive unit to move the valve element when the on-off valve opens the processing liquid flow path. This facilitates the flow regulation of the processing liquid by the valve element drive unit which is current 1 y made by the operator&#39;s sense. Moreover, since prevention of the drips of the processing liquid as well as the flow regulation of the processing liquid are performable with the same valve element drive unit, the needless configuration is omittable to achieve space saving compared to the configuration in which the valve element drive unit is provided individually. 
     Moreover, such control causes the valve element drive unit to move the valve element to a suck back reference position for decreasing the flow rate of the processing liquid, and then causes the on-off valve to close the processing liquid flow path, and causes the valve element drive unit to move the volume variation unit cooperating with the valve element for increasing the volume of the processing liquid flow path. This decreases the flow rate of the processing liquid when the on-off valve closes the processing liquid flow path, leading to prevention of the drips of the processing liquid caused by the increased flow rate of the processing liquid. That is, this certainly allows prevention of the drips. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram schematically illustrating a substrate treating apparatus according to one embodiment. 
         FIG. 2  is a longitudinal sectional view of an on-off valve and a suck back valve with a flow rate regulating function. 
         FIG. 3  is a timing chart illustrating operation of the on-off valve and the suck back valve with the flow rate regulating function. 
         FIG. 4( a )  illustrates operation of the processing liquid supplying unit and a position of the dispensing nozzle relative to a substrate,  FIG. 4( b )  illustrates one example of a dispensation amount (flow rate) in a position relationship of  FIG. 4( a ) , and  FIG. 4( c )  illustrates another example of the dispensation amount (flow rate) in the position relationship of  FIG. 4( a ) . 
         FIG. 5  is a timing chart illustrating operation of an on-off valve and a suck back valve with a flow rate regulating function according to one modification. 
         FIG. 6  is a longitudinal sectional view of the on-off valve and the suck back valve with the flow rate regulating function according to the modification. 
         FIG. 7  illustrates operation of a processing liquid supplying unit according to the modification. 
         FIG. 8  is a block diagram schematically illustrates a current 1 y-used processing liquid supplying apparatus. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes embodiments of the present invention with reference to drawings.  FIG. 1  is a block diagram schematically illustrating a substrate treating apparatus according to one embodiment.  FIG. 2  is a longitudinal sectional view of an on-off valve and a suck back valve having a flow rate regulating function. 
     &lt;Configuration of Substrate Treating Apparatus  1 &gt;Reference is made to  FIG. 1 . A substrate treating apparatus  1  includes a holding rotator  2  that holds and rotates a substrate W in a substantially horizontal attitude, and a processing liquid supplying unit  3  that supplies a processing liquid. Examples of the processing liquid used include a coating liquid such as a photoresist, a developer, a solvent, or a rinse liquid such as deionized water. Here, the processing liquid supplying unit  3  corresponds to the processing liquid supplying apparatus in the present invention. 
     The holding rotator  2  includes a spin chuck  4  that holds a rear face of the substrate W through vacuum-suction, and a rotation drive unit  5  that is composed of a motor and the like for rotating the spin chuck  4  around a rotary shaft AX in a substantially vertical direction. A cup  6  that is movable upwardly/downwardly is disposed around the holding rotator  2  so as to surround a lateral side of the substrate W. 
     The processing liquid supplying unit  3  includes a dispensing nozzle  11  that dispenses the processing liquid to the substrate W, a processing liquid supplying source  13  composed of a tank and the like for storing the processing liquid, and a processing liquid pipe  15  that feeds the processing liquid from the processing liquid supplying source  13  to the dispensing nozzle  11 . A pump P, an on-off valve  17 , and a suck back valve  19  having a flow rate regulating function rate are interposingly arranged on the processing liquid pipe  15  in this order from the processing liquid supplying source  13 . It should be noted that another element may be interposingly arranged on the processing liquid pipe  15 . For instance, a filter, not shown, may be interposingly arranged between the pump P and the on-off valve  17 . Here, the processing liquid pipe  15  corresponds to the pipe in the present invention. 
     A nozzle moving mechanism  21  causes the dispensing nozzle  11  to move between a standby pot  23  outside the substrate W and a dispensing position above the substrate W. The nozzle moving mechanism  21  is composed of a holder arm, a motor, and the like. Here, the dispensing nozzle  11  is disposed downstream of the suck back valve  19 , and is connected to a processing liquid flow path  70  mentioned later via the processing liquid pipe  15 . 
     The pump P feeds out the processing liquid to the dispensing nozzle  11 . The on-off valve  17  performs supply and stops the supply of the processing liquid. The suck back valve  19  is combined with the on-off valve  17  to suck back the processing liquid and regulate a flow rate of the processing liquid. The on-off valve  17  and the suck back valve  19  are described later in detail. It should be noted that the suck back valve  19  having the flow rate regulating function is also referred to as a flow regulating valve having a suck back function. 
     The processing liquid supplying unit  3  includes a controller  31  composed of a central processing unit (CPU) and the like, and an operating unit  33  for operating the substrate treating apparatus  1 . The controller  31  controls each element of the substrate treating apparatus  1 . The operating unit  33  includes a display unit such as a liquid crystal monitor, a memory unit such as a ROM (Read-only Memory), a RAM (Random-Access Memory), and a hard disk, and an input unit such as a keyboard, a mouse, and various types of buttons. The memory unit stores various conditions for controlling the on-off valve  17  and the suck back valve  19 , and other conditions for substrate treatment. 
     &lt;On-Off Valve  17  and Suck Back Valve  19  with Flow-Rate Regulating Function&gt; 
     The following describes detailed configurations of the on-off valve  17  and the suck back valve  19 . Reference is made to  FIG. 2 . The on-off valve  17  opens/closes a processing liquid flow path  70  composed of an upstream flow path  43 , an on-off chamber internal flow path  50 , a coupling flow path  51 , a valve chamber internal flow path  63 , and a downstream flow path  67 , which are to be mentioned later. The suck back valve  19  sucks back the processing liquid in combination with the operation of the on-off valve  17 , and regulates the flow rate of the processing liquid. 
     &lt;Configuration of On-Off Valve  17 &gt; 
     The on-off valve  17  is disposed in the course of the processing liquid pipe  15 , and is composed of the upstream flow path  43 , the on-off chamber internal flow path  50  of an on-off chamber  41 , and the coupling flow path  51  in communication with the valve chamber  61  of the suck back valve  19  which are connected to one another in series. The processing liquid pipe  15  is attached to the on-off chamber  41  via an upstream joint  71 , and is in fluid communication with the upstream flow path  43  of the on-off valve  17 . The on-off valve  17  performs switching of flow of the processing liquid between a circulation state and a blocked state in the on-off chamber  41  by on-off operation, which is to be mentioned later. 
     A first end of the upstream flow path  43  is in communication with a bottom of the on-off chamber internal flow path  50  of the on-off chamber  41 . Here, a second end of the processing liquid pipe  15  is connected to the pump P. Accordingly, the processing liquid fed out through the pump P passes through the upstream flow path  43  into the on-off chamber internal flow path  50  of the on-off chamber  41 . 
     The on-off chamber  41  is a hollow box, and includes inside thereof a piston  42 , a spring  47 , a partition  45 , and a diaphragm  46  as the valve element. The piston  42  is slidably disposed within the on-off chamber  41  in a vertical direction of the drawing. The spring  47  is disposed between a top face of the piston  42  and an upper inner wall of the on-off chamber  41 . 
     The partition  45  is a flat plate member that divides the interior of the on-off chamber  41  vertically, and the center thereof is passed through by the piston  42 . A contact portion between the piston  42  and the partition  45  is completely sealed although the piston  42  is slidably relative to the partition  45 . Accordingly, when air is blown into the on-off chamber  41  through a gas pipe  48   a  , the air does not leak below the partition  45  (adjacent to the diaphragm  46 ). 
     A periphery edge of the diaphragm  46  is fixed to an inner wall of the on-off chamber  41 . The center of the diaphragm  46  is fixed to a lower end of the piston  42 . 
     A first valve seat  44  is disposed at the center of the bottom of the on-off chamber internal flow path  50  in the on-off chamber  41 . The coupling flow path  51  provides communication between the first valve seat  44  of the on-off chamber  41  and a valve chamber internal flow path  63  in the valve chamber  61  of the suck back valve  19  to be mentioned later. 
     An intake and exhaust port  49  for performing intake and exhaust of gas from a gas supplying unit  48  is disposed on a side wall of the on-off chamber  41 . The gas supplying unit  48  is controlled by the controller  31 . The gas supplying unit  48  is composed of a gas supplying source, a gas on-off valve, a speed controller (each not shown) and the like. The controller  31  performs control so as to cause the gas supplying unit  48  to supply gas to the intake and exhaust port  49  through the gas pipe  48   a  and to exhaust gas through the intake and exhaust port  49 . 
     With the configuration of the on-off valve  17  mentioned above, when the gas supplying unit  48  supplies the gas into the on-off chamber  41  through the intake and exhaust port  49 , the piston  42  is pressed upward against an elastic force of the spring  47  (under the condition as illustrated by solid lines in  FIG. 2 ). When the piston  42  is pressed upwardly, the diaphragm  46  fixed thereto is deformed to be remote from the first valve seat  44 . 
     As illustrated by the solid lines in  FIG. 2 , when the diaphragm  46  as the valve element is remote from the first valve seat  44 , communication is provided among the upstream flow path  43 , the on-off chamber internal flow path  50 , and the coupling flow path  51 . Then, the processing liquid fed out from the pump P passes from the upstream flow path  43  through the on-off chamber internal flow path  50 , the coupling flow path  51 , a valve chamber internal flow path  63  mentioned later, and the downstream flow path  67  into the dispensing nozzle  11 , and accordingly, the processing liquid is dispensed from the dispensing nozzle  11  to the substrate W. In other words, the condition illustrated by the solid lines in  FIG. 2  corresponds to the condition in which the processing liquid flow path  70  are opened to pass the processing liquid. That is, the above corresponds to the condition (opened condition) where the on-off valve  17  opens the processing liquid flow path  70 . 
     In contrast to this, when the gas supplying unit  48  exhausts gas within the on-off chamber  41  through the intake and exhaust port  49 , pressure within the on-off chamber  41  decreases, and thus no pressure exists that presses the piston  42  upwardly against the restoring force of the spring  47 . Accordingly, the piston  42  is pressed downwardly by the restoring force of the spring  47  as illustrated by dotted lines in  FIG. 2 . When the piston  42  is pressed downwardly, the diaphragm  46  fixed thereto is deformed as illustrated by the dotted lines in  FIG. 2  to be sealed tight 1 y with the first valve seat  44 . 
     As illustrated in  FIG. 2 , when the diaphragm  46  as the valve element is tight 1 y sealed with the first valve seat  44 , an unblocked condition is provided between the on-off chamber flow path  50  and the coupling flow path  51 . Accordingly, the processing liquid fed out from the pump P is not able to flow toward the coupling flow path  51 , and thus the processing liquid stops flowing. That is, the above leads to the condition where the processing liquid flow path  70  is blocked by the on-off valve  17  (a closed condition). 
     As mentioned above, the gas supplying unit  48  functions as an actuating device of actuating the diaphragm  46  as the valve element by the piston  42 , the spring  47 , and the like. 
     &lt;Configuration of Suck Back Valve  19  with Flow-Rate Regulating Function&gt; 
     As illustrated in  FIG. 2 , the suck back valve  19  is disposed downstream of the on-off valve  17 . The suck back valve  19  includes a valve chamber  61  as a hollow box member, a needle  62  that is movable upwardly/downwardly in  FIG. 2  within the valve chamber  61 , and a downstream flow path  67 . 
     The valve chamber internal flow path  63  is disposed within the valve chamber  61  for passing the processing liquid. In addition, a second valve seat  64  for receiving the needle  62  is disposed at the center of the bottom of the valve chamber internal flow path  63  in the valve chamber  61 . An opening  64   a  is provided in the second valve seat  64  for passing the processing liquid. The opening  64   a  is in communication with the downstream flow path  67 . The processing liquid pipe  15  is attached to the valve chamber  61  via a downstream joint  72 , and thus in fluid communication with the downstream flow path  67  of the suck back valve  19 . When the second valve seat  64  receives the needle  62 , the needle  62  blocks the opening  64   a . This achieves closure of a flow path between the valve chamber internal flow path  63  and the downstream flow path. 
     The needle  62  is configured to adjust a width of the flow path (an aperture of the opening  64   a ) provided between the valve chamber internal flow path  63  and the downstream flow path  67 , i.e., an aperture of the processing liquid flow path  70 . In other words, the needle  62  adjusts a clearance to the opening  64   a  of the second valve seat  64 , thereby regulating a flow rate of the processing liquid that passes through the clearance. 
     Moreover, the suck back valve  19  includes a diaphragm  66  that is attached to a tip portion of the needle  62  and a motor (electric motor)  68  that drives the needle  62  upwardly/downwardly in  FIG. 2 . A periphery edge of the diaphragm  66  is fixed to a side wall  61   a  of the valve chamber  61 , and the diaphragm  66  divides the interior of the valve chamber  61  across a moving direction of the needle  62 . 
     In addition, the diaphragm  66  cooperates with the needle  62  as in  FIG. 2 . This allows the diaphragm  66  to vary the volume of the flow path from the coupling flow path  51  downstream of the on-off valve  17  via the valve chamber internal flow path  63  to the downstream flow path  67 . In other words, movement of the needle  62  allows adjustment in clearance to the second valve seat  64  and variation in volume of the flow path from the coupling flow path  51  via the valve chamber internal flow path  63  to the downstream flow path  67  simultaneously. 
     Here, the needle  62  corresponds to the valve element in the present invention. The diaphragm  66  corresponds to the volume variation unit in the present invention. Moreover, the motor  68  corresponds to the valve element drive unit in the present invention. 
     The controller  31  controls the motor  68  by a given number of pulse, for example. A mechanism not shown converts rotation of the motor  68  to apply an upward/downward driving force to the needle  62 . For instance, the controller  31  causes the motor  68  to move the diaphragm  66  cooperating with the needle  62  when the on-off valve  17  is closed, thereby increasing the volume of the flow path for suck back from the coupling flow path  51  via the valve chamber internal flow path  63  to the downstream flow path  67 . Moreover, the controller  31  causes the motor  68  to move the needle  62  when the on-off valve  17  is opened for regulating the flow rate of the processing liquid. Moreover, it is preferred that a sensor such as a rotary encoder, not shown, is attached to the motor  68  for obtaining an accurate moving amount of the needle  62  in the upward/downward direction. 
     In addition, the on-off valve  17  is disposed adjoining the suck back valve  19 . Accordingly, the on-off valve  17  is integrated with the suck back valve  19  for achieving a simplified configuration. Moreover, the upstream flow path  43  of the on-off valve  17 , the downstream flow path  67  of the suck back valve  19 , and the coupling flow path  51  connecting the on-off chamber internal flow path  50  and the valve chamber internal flow path  63  are formed as a single part. In this case, the on-off chamber  41  and the valve chamber  61  may be partially formed as a single part as the on-off chamber  41  and the valve chamber  61  illustrated below the dotted lines L in  FIG. 2 . 
     Moreover, the upstream flow path  43 , the on-off chamber internal flow path  50 , the coupling flow path  51 , the valve chamber internal flow path  63 , and the downstream flow path  67  form the processing liquid flow path  70  that passes the processing liquid. Here, the coupling flow path  51 , the valve chamber internal flow path  63 , and the downstream flow path  67  correspond to the downstream processing liquid flow path in the present invention. 
     &lt;Operation of Substrate Treating Apparatus  1 &gt; 
     The following describes operation of the substrate treating apparatus  1 , especially operation of the processing liquid supplying unit  3 .  FIG. 3  is a timing chart illustrating operation of the on-off valve  17  and the suck back valve  19  having a flow-rate regulating function. The controller  31  controls each element of the substrate treating apparatus  1  in accordance with dispensing conditions (recipes) set in advance. 
     With the embodiment of the present invention, the motor  68  of the suck back valve  19  moves the needle  62  in response to opening/closing of the on-off valve  17  to perform suck back (drip prevention) and flow regulation of the processing liquid. At this time, the suck back leads to irregular flow regulation, whereas the flow regulation leads to irregular suck back. In the embodiment of the present invention, operation is performed in consideration with this point. 
     In the suck back valve  19 , the motor  68  performs upward/downward movement of the needle  62 . Here, the upward movement corresponds to remote movement of the needle  62  from the second valve seat  64 . The downward movement corresponds to approach of the needle  62  to the second valve seat  64 . Moreover, in  FIGS. 3 and 5  mentioned later, the position “ 0 ” of the needle  62  is the position where the needle  62  moves closest to the second valve seat  64  regardless of flow of the processing liquid. 
     First 1 y, in the substrate treating apparatus  1  of  FIG. 1 , a transport mechanism not shown transports the substrate W to the holding rotator  2 . The holding rotator  2  holds the rear face of the substrate W, and rotates the held substrate W. The nozzle moving mechanism  21  moves the dispensing nozzle  11  from the standby pot  23  outside the substrate W to the dispensing position above the substrate W. The controller  31  performs control to the on-off valve  17  and the suck back valve  19  to dispense the processing liquid from the dispensing nozzle  11 . Here, the pump P is driven. When the on-off valve  17  is opened, the processing liquid stored in the processing liquid supplying source  13  is dispensed from the dispensing nozzle  11 . 
     At time t 0  in  FIG. 3 , the on-off valve  17  is opened and the processing liquid is dispensed from the dispensing nozzle  11 . In addition, in the suck back valve  19 , the motor  68  causes the needle  62  to move to a position NA while the on-off valve  17  is opened, thereby regulating the flow rate of the processing liquid corresponding to the position NA. 
     The controller  31  performs control to decrease the flow rate to certainly avoid drips before the on-off valve  17  is closed when the dispensing nozzle  11  stops dispensation of the processing liquid. Specifically, the controller  31  causes the motor  68  to move the needle  62  to a suck back reference position SB 0  for decreasing the flow rate of the processing liquid at time t 1 . Thereafter, the controller  31  causes the on-off valve  17  to close the flow path between the on-off chamber internal flow path  50  of the processing liquid flow path  70  and the coupling flow path  51  at time t 2 . 
     Moreover, the controller  31  causes the motor  68  to move the needle  62  to a suck back executable position SB 1  at time t 3 . In other words, the controller  31  causes the motor  68  to move the diaphragm  66  cooperating with the needle  62  for increasing a volume of the flow path from the coupling flow path  51  via the valve chamber internal flow path  63  to the downstream flow path  67 . This allows suck back (suction) of the processing liquid within the tip end of the dispensing nozzle  11 . It should be noted that the time t 2  may be the same timing as the time t 3 . Alternatively, the time t 2  may be delayed a litt 1 e from the time t 3 . In addition, the suck back includes a set moving amount SD of the needle  62 . The moving amount SD may be constant, or may be varied. 
     After dispensation of the processing liquid to the substrate W is finished, the substrate W on the holding rotator  2  is replaced. Specifically, the holding rotator  2  in  FIG. 1  stops rotation of the substrate W, and releases the holding of the substrate W. The nozzle moving mechanism  21  causes the dispensing nozzle  11  to move to the standby pot  23  outside the substrate W. Then, the transport mechanism not shown replaces the substrate W. As noted above, the holding rotator  2  holds the rear face of the substrate W, and rotates the held substrate W. In addition, the nozzle moving mechanism  21  moves the dispensing nozzle  11  from the standby pot  23  outside the substrate W to the dispensing position above the substrate W. 
     The processing liquid is again dispensed from the dispensing nozzle  11 . The suck back causes the needle  62  to move depending on the configuration of the suck back valve  19  in the present invention. Movement of the needle  62  needs another flow regulation. The controller  31  causes the motor  68  to move the needle  62  from the suck back executable position SB 1  of the needle  62  while the volume of the flow path is increased from the coupling flow path  51  through the valve chamber internal flow path  63  to the downstream flow path  67  at time t 4 , and then to open the on-off valve  17  at time t 5 . 
     The following describes two examples of controlling operation at the time t 4 . Here, the two examples of controlling operation correspond to upward movement to a position NB and downward movement to a position NC. 
     First 1 y, the case is to be described where the needle  62  is moved upwardly from the suck back executable position SB 1  to the position NB. The controller  31  causes the motor  68  to move the needle  62  from the suck back executable position SB 1  to the position NB at the time t 4 . The diaphragm  66  cooperating with the needle  62  moves upward in synchronization with the upward movement of the needle  62 . Accordingly, further suck back is to be performed. Under such a condition, the controller  31  causes the on-off valve  17  to open the processing liquid flow path  70  for dispensing the processing liquid from the dispensing nozzle  11  at the time t 5 . Since the needle  62  is moved upward from the suck back executable position SB 1  when the on-off valve  17  opens the processing liquid flow path  70 , no processing liquid is pushed out from the dispensing nozzle  11  to achieve further suck back. This clears possibility of drips. 
     The following describes downward movement of the needle  62  from the suck back executable position SB 1  to the position NC. The controller  31  causes the motor  68  to move the needle  62  at the time t 4  from the suck back executable position SB 1  to the position NC. Downward movement of the needle  62  pushes out the processing liquid. Accordingly, the processing liquid may be dispensed from the dispensing nozzle  11  depending on the downward movement amount of the needle  62 . 
     Then, the controller  31  causes the motor  68  to change a moving speed of the needle  62  so as to obtain a preset flow rate F when the needle  62  is moved downward to the position NC where the flow rate is changed to the preset low rate F. That is, a lowering speed of the needle  62  (see gradient  81  in  FIG. 3 ) is adjusted in such a manner that the processing liquid is pushed out at the flow rate F equal to or close to the flow rate F at the position NC of the needle  62 . Subsequent 1 y, the controller  31  causes the on-off valve  17  to open the processing liquid flow path  70  at the time t 5  for dispensing the processing liquid from the dispensing nozzle  11 . Since the lowering speed of the needle  62  is adjusted and subsequent 1 y the on-off valve  17  is turned opened, the processing liquid is able to flow naturally and successively at the preset flow rate F. 
     After the processing liquid is dispensed from the dispensing nozzle  11  for a given period of time, the needle  62  of the suck back valve  19  is moved downwardly to the suck back reference position SB 0  at the time t 6  to decrease the flow rate. Thereafter, the on-off valve  17  is turned closed at time t 7 . Then, the needle  62  of the suck back valve  19  is moved upwardly to the suck back executable position SB 1  at time t 8  to move the diaphragm  66  cooperating with the needle  62  upwardly for suck back. 
     The following describes the case where a dispensation rate is changed within the same substrate W with reference to  FIGS. 4( a ) to 4( c ) . With the present invention, as in the position NA and the position NB in  FIG. 3 , the flow regulation is readily performable to every different substrate W or every set of substrates when the substrates are prepared in sets. In addition, the flow regulation within the same substrate W is readily performable. 
       FIG. 4( a )  illustrates a position of the dispensing nozzle  11  relative to the substrate W.  FIGS. 4( b ) and 4( c )  each illustrate one example of a dispensation amount (flow rate) in the positional relationship of  FIG. 4( a ) . There may be the case where the nozzle moving mechanism  21  causes the dispensing nozzle  11  to move from the center C of the substrate W to an edge E of the substrate W while the dispensing nozzle  11  dispenses the processing liquid. In such a case, a dispensation amount may be increased to a width of 50 mm from the edge E, for example, as in  FIG. 4( b ) . Alternatively, the amount may be decreased if necessary. Alternatively, the processing liquid may be dispensed from the dispensing nozzle  11  at the flow rate with the gradient as in  FIG. 4( c ) . 
     With the present embodiment, provided downstream of the on-off valve  17  that opens/closes the processing liquid flow path  70  are the needle  62  that adjusts the width of the flow path (aperture of the opening  64   a ) formed between the valve chamber internal flow path  63  and the downstream flow path  67 , and the diaphragm  66  that cooperates with the needle  62  and changes the volume of the flow path from the coupling flow path  51  downstream of the on-off valve  17  via the valve chamber internal flow path  63  to the downstream flow path  67 . The motor  68  drives the needle  62 . The controller  31  causes the motor  68  to move the diaphragm  66  cooperating with the needle  62  for increasing the volume of the flow path from the coupling flow path  51  via the valve chamber internal flow path  63  to the downstream flow path  67  when the on-off valve  17  closes the processing liquid flow path  70 . Accordingly, this allows suck back, leading to prevention of drips of the processing liquid. In addition, the controller  31  causes the motor  68  to move the needle  62  for regulating the flow rate of the processing liquid when the on-off valve  17  opens the processing liquid flow path  70 . This facilitates the flow regulation of the processing liquid by the motor  68  which is current 1 y made by the operator&#39;s sense. Moreover, since prevention of the drips of the processing liquid as well as the flow regulation of the processing liquid are performable with the same motor  68 , a needless configuration is omittable to achieve space saving compared to the configuration in which the motor  68  is provided individually. This allows supply of the processing liquid at different flow rates to every substrate W, and the flow rate of the processing liquid is variable to the same substrate W in the course of the supply. 
     Moreover, with the present embodiment, the on-off valve  17  is primarily used for opening/closing, and the suck back valve  19  performs fine adjustment. Accordingly, the on-off valve  17  with the simplified configuration is selectable. 
     Moreover, the motor  68  moves the needle  62  of the suck back valve  19 , leading to easy suck back at plural times, i.e., in multiple stages. This also achieves ready variation in position of the needle  62  for the flow regulation. 
     Moreover, the controller  31  causes the motor  68  to move the needle  62  to the suck back reference position SB 0  for decreasing the flow rate of the processing liquid, and thereafter causes the on-off valve  17  to close the processing liquid flow path  70  and causes the motor  68  to move the diaphragm  66  cooperating with the needle  62  for increasing the volume of the processing liquid flow path  70 . Accordingly, the flow rate of the processing liquid becomes decreased when the on-off valve  17  closes the processing liquid flow path  70 , leading to suppressed drips of the processing liquid caused by the increased flow rate of the processing liquid. That is, this certainly allows prevention of the dripping. 
     Moreover, the controller  31  causes the motor  68  to move the needle  62  from the position of the needle  62  where the volume of the flow path increases from the coupling flow path  51  via the valve chamber internal flow path  63  to the downstream flow path  67  to a position at which the flow rate is changed to the preset flow rate, and causes the on-off valve  17  to open the processing liquid flow path  70 . Although the position of the needle  62  is changed by the suck back, the preset flow rate of the processing liquid is able to be supplied upon opening of the processing liquid flow path  70  with the on-off valve  17 . 
     Moreover, the needle  62  is moved upwardly to the position where the flow rate is changed to the preset flow rate upon the opening of the processing liquid flow path  70  with the on-off valve  17 . Since the needle  62  is moved upwardly for the preset flow rate upon the opening of the processing liquid flow path  70  with the on-off valve  17 , no processing liquid is pushed out and further suck back is performed. This clears possibility of liquid drips. 
     Moreover, the lowering speed (see the gradient  81  in  FIG. 3 ) of the needle  62  is changed such that the flow rate is changed to the preset flow rate when the motor  68  causes the needle  62  to move downward to a position where the flow rate is changed to the preset flow rate. For instance, the lowering speed of the needle  62  is changed such that the dispensing nozzle  11  dispenses the processing liquid at the preset flow rate when the needle  62  is moved downwardly to a position where the flow rate is changed to the preset flow rate. This allows the flow rate of the processing liquid dispensed by the movement of the needle  62  to approach to a flow rate at which the on-off valve  17  opens the processing liquid flow path  70 . 
     Moreover, the processing liquid supplying apparatus  3  further includes the dispensing nozzle  11  downstream of the needle  62 , the dispensing nozzle  11  being connected to the processing liquid flow path  70  via the processing liquid pipe  15  for dispensing the processing liquid. This allows suction of the processing liquid within the dispensing nozzle  11  for flow regulation of the processing liquid dispensed from the dispensing nozzle  11 . 
     The present invention is not limited to the foregoing examples, but may be modified as follows. 
     (1) In the embodiments mentioned above, the needle  62  of the suck back valve  19  is moved downwardly to the suck back reference position SB 0  before the on-off valve  17  is turned off as at the time t 1  in  FIG. 3 . In contrast to this, the on-off valve  17  may be turned off without the movement of the needle  62  when the downward movement to the suck back reference position SB 0  is not needed. 
     The on-off valve  17  is turned off at the time til in  FIG. 5  without the downward movement of the needle  62  of the suck back valve  19  at the position NA. The needle  62  is moved upwardly to the position SB 2  by a preset moving amount SD at the time t 12 . That is, the diaphragm  66  cooperating with the needle  62  is moved upwardly for suck back. After the substrate W is replaced, the dispensing nozzle  11  again dispenses the processing liquid while the needle  62  is disposed at the position NC lower than the position NA. 
     The following describes the example of the operation in this case. The nozzle moving mechanism  21  moves the dispensing nozzle  11  to the standby pot  23 . Under such a condition, the needle  62  is moved downwardly to a position NC at time t 13 . At this time, the processing liquid pushed out from the dispensing nozzle  11  is collected within the standby pot  23 . Then, the needle  62  is moved upwardly by the moving amount SD to the position SB 3 . That is, the diaphragm  66  cooperating with the needle  62  performs suck back. It should be noted that dummy dispensation of the processing liquid may be made while the on-off valve  17  is turned on as illustrated by the numeral  83  between the time t 14  to t 15  in  FIG. 5 . 
     Thereafter, the nozzle moving mechanism  21  moves the dispensing nozzle  11  from the standby pot  23  to the above of the substrate W. At time t 16 , the needle  62  is moved downwardly for flow regulation. At time t 17 , the on-off valve  17  is turned on to dispense the processing liquid from the dispensing nozzle  11 . Moreover, at time t 18 , the on-off valve  17  is turned off to stop dispensation of the processing liquid from the dispensing nozzle  11 . At time t 19 , the diaphragm  66  cooperating with the needle  62  performs suck back. 
     In addition, at the time t 13 , the lowering speed of the needle  62  (see the gradient  81  in  FIGS. 3 and 5 ) may be adjusted such that the flow rate is equal to or close to the flow rate F at the position NC of the needle  62  above the substrate W to push out the processing liquid from the dispensing nozzle  11  for flow regulation. Then, the on-off valve  17  may be turned on subsequent 1 y. 
     (2) In the embodiments and the modification (1) mentioned above, the diaphragm  66  is provided as the volume variation unit of the suck back valve  19 . In contrast to this, as in  FIG. 6 , the needle  82  may include a partition  82   a  across the moving direction of the needle  82 , and the partition  82   a  may be movable while contacting to the side inner wall of the valve chamber  61  via a sealed holder  82   b  such as an O-ring. 
     (3) In the embodiments and the modifications mentioned above, the developer is occasionally used as the processing liquid. This allows prevention of drips of the developer, leading to flow regulation of the developer. As illustrated in  FIG. 7 , the controller  31  causes the nozzle moving mechanism  21  to move the dispensing nozzle  11  to the standby pot  23  where the tip end of the dispensing nozzle  11  is immersed into the container  85  in which deionized water remains. Then, the controller  31  causes the motor  68  of the suck back valve  19  to reciprocate the diaphragm  66  cooperating with the needle  62  while the upstream flow path  43  is closed. The tip end of the dispensing nozzle  11  is immersed into the deionized water, and the deionized water is sucked, the sucked deionized water is retained for a given period of time, or the sucked deionized water is pushed out, whereby the tip end of the dispensing nozzle  11  is cleanable.  FIG. 7  illustrates a developer layer by the numeral  86 , a gas layer such as air by the numeral  87 , and the deionized water by the numeral  88 . 
     (4) In the embodiments and the modifications mentioned above, the on-off valve  17  is an air operated valve, but may be a motor driven valve such as the suck back valve  19 . In addition, the valve element of the on-off valve  17  is composed of the diaphragm  46 , but may allow flow regulation such as the needle  62  of the suck back valve  19 . The on-off valve  17  has the configuration as  FIG. 2 , but may have another known configuration. 
     (5) In the embodiments and the modifications mentioned above, the processing liquid flows at the suck back reference position SB 0 . Alternatively, no processing liquid may flow at the suck back reference position SB 0  as necessary. 
     (6) In the embodiments and the modifications mentioned above, each flow path in the suck back valve  19  is formed as a single part, but may be an individual part. That is, the on-off valve  17  and the suck back valve  19  are formed individually. In this case, the on-off valve  17  is connected to the suck back valve  19  via the processing liquid pipe  15 . 
     REFERENCE SIGNS LIST 
       1  . . . substrate treating apparatus 
       3  . . . processing liquid supplying unit 
       11  . . . dispensing nozzle 
       15  . . . processing liquid pipe 
       17  . . . on-off valve 
       19  . . . suck back valve 
       31  . . . controller 
       43  . . . upstream flow path 
       50  . . . on-off chamber internal flow path 
       51  . . . coupling flow path 
       62 ,  82  . . . needle 
       63  . . . valve chamber internal flow path 
       66  . . . diaphragm 
       67  . . . downstream flow path 
       68  . . . motor 
       70  . . . processing liquid flow path 
       81  . . . gradient 
     t 0  to t 8 , t 1 l to t 19  . . . time