Patent Publication Number: US-2023136494-A1

Title: Valve system, output monitoring method and output adjusting method for diaphragm valve, and semiconductor manufacturing apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a valve system, an output monitoring method and an output adjusting method for diaphragm valve, and a semiconductor manufacturing apparatus using the valve system. 
     BACKGROUND ART 
     In a process of depositing a film on a substrate by atomic layer deposition (ALD) method or a process of etching by atomic layer etching (ALE) method, in order to stably supply a process gas, the process gas supplied from a fluid control device is temporarily stored in a tank as a buffer, and a diaphragm valve provided in the immediate vicinity of the processing chamber is frequently opened and closed to supply the process gas from the tank to a processing chamber in a vacuum atmosphere. As such a diaphragm valve provided in the immediate vicinity of the processing chamber, see for example, Patent Literature 1. 
     In the semiconductor manufacturing process by ALD method or ALE method, it is necessary to precisely adjust the mass of the process gas. 
     PATENT LITERATURE 
     
         
         PTL 1: Japanese Laid-Open Patent Application No. 2007-64333 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the prior art, it was impossible to monitor in real time the mass of the gas supplied from the diaphragm valve which is opened and closed periodically. 
     It was also difficult to control the output mass of the gases supplied from several diaphragm valves equally due to difference between the diaphragm valves in mechanical characteristic and flow path resistance etc. 
     One of the objects of the present invention is to provide a valve system capable of monitoring in real time the output mass of the gas supplied from a valve which is opened and closed periodically. 
     Another object of the present invention is to provide a valve system capable of adjusting the output mass of gas supplied from a valve, which is opened and closed periodically, toward a target mass. 
     Still another object of the present invention is to provide a semiconductor manufacturing apparatus using the above-described valve system. 
     Solution to Problem 
     The valve system according to the present invention comprises: a diaphragm valve including a body defining a flow path through which fluid flows, a diaphragm defining a portion of the flow path and opening and closing flow path by contacting to and separating from a valve seat provided in the body, an operating member for operating the diaphragm, the operating member movably provided between a closed position for making the diaphragm close the flow path and an open position for making the diaphragm open the flow path, and a drive mechanism for moving the operating member to the open or closed position; 
     a displacement sensor for detecting a displacement of the operating member with respect to the body; 
     a drive control unit for operating the drive mechanism to make the diaphragm periodically open and close the flow path; 
     an output monitor unit that calculates an output mass of a fluid that passes through a gap between the diaphragm and the valve seat and is output from the diaphragm valve using the detected displacement data of the displacement sensor. 
     Preferably, a configuration may be adopted in which the output monitor unit calculates the output mass based on a time integration of the displacement data detected by the displacement sensor. 
     The valve system of the present invention further comprises a lift amount adjustment mechanism for adjusting the lift amount of the diaphragm defined by the operating member positioned in the open position. 
     Preferably, a configuration may be adopted in which the valve system of the present invention further comprises an output adjustment unit that determines the adjustment lift amount based on the output mass calculated by the output monitor unit, and makes the lift amount adjustment mechanism adjust the lift amount with the determined adjustment lift amount to adjust the output mass of the fluid output from the diaphragm valve. 
     An output monitoring method of a diaphragm valve of the present invention is a method for monitoring an output of a diaphragm valve comprising: a body defining a flow path through which a fluid flows; a diaphragm defining a portion of the flow path and opening and closing the flow path by contacting to and separating from a valve seat provided in the body; an operating member for operating the diaphragm, the operating member movably provided between a closed position for making the diaphragm close the flow path and an open position for making the diaphragm open the flow path; and a drive mechanism for moving the operating member to the open or closed position, 
     the method comprising: supplying a pressure-controlled fluid to the diaphragm valve; 
     operating the driving mechanism to make the diaphragm periodically open and close the flow path; 
     detecting a displacement of the operating member with respect to the body; and 
     using the detected displacement data, calculating the output mass of the fluid that passes through a gap between the diaphragm and the valve seat and is output from the diaphragm valve. 
     An output adjusting method of a diaphragm valve of the present invention is a method for adjusting an output of a diaphragm valve comprising: a body defining a flow path through which a fluid flows; a diaphragm defining a portion of the flow path and opening and closing the flow path by contacting to and separating from a valve seat provided in the body; an operating member for operating the diaphragm, the operating member movably provided between a closed position for making the diaphragm close the flow path and an open position for making the diaphragm open the flow path; a drive mechanism for moving the operating member to the open or closed position; and a lift amount adjustment mechanism for adjusting a lift amount of the diaphragm valve defined by the operating member positioned at the open position, 
     the method comprising: supplying a pressure-controlled fluid to the diaphragm valve; 
     operating the driving mechanism to make the diaphragm periodically open and close the flow path; 
     detecting a displacement of the operating member with respect to the body; 
     using the detected displacement data, calculating an output mass of the fluid that passes through a gap between the diaphragm and the valve seat and is output from the diaphragm valve; and 
     determining an adjustment lift amount based on the calculated output mass and adjusting a lift amount by the lift amount adjustment mechanism with the determined adjustment lift amount. 
     A semiconductor manufacturing apparatus of the present invention is a semiconductor manufacturing apparatus comprising the above-described valve system for controlling a supply of a process gas in a manufacturing process of a semiconductor device requiring a processing step with the process gas in a sealed chamber. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to monitor in real time the mass of a gas supplied from the valve which is periodically opened and closed. 
     Further, according to the present invention, it is possible to precisely adjust an output mass of a fluid supplied every time the valve is opened and closed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1 A  is a longitudinal sectional view of a diaphragm valve, and is a sectional view taken along a line  1   a - 1   a  in  FIG.  1 B . 
         FIG.  1 B  is a top view of the diaphragm valve in  FIG.  1 A . 
         FIG.  1 C  is an enlarged cross-sectional view of an actuator portion of the diaphragm valve in  FIG.  1 A . 
         FIG.  1 D  is an enlarged cross-sectional view of the actuator portion along a  1 D- 1 D line in  FIG.  1 B . 
         FIG.  1 E  is an enlarged cross-sectional view in a circle A in  FIG.  1 A . 
         FIG.  2    is an explanatory diagram showing the operation of the piezoelectric actuator. 
         FIG.  3    is an enlarged cross-sectional view of a main portion for explaining a fully closed state of the diaphragm valve in  FIG.  1 A . 
         FIG.  4    is an enlarged cross-sectional view of a main portion for explaining the fully open state of the diaphragm valve in  FIG.  1 A . 
         FIG.  5    is an enlarged cross-sectional view of a main portion for explaining the state when adjusting the flow rate (when the flow rate is reduced) of the valve device in  FIG.  1 A . 
         FIG.  6    is an enlarged cross-sectional view of a main portion for explaining a state when adjusting the flow rate (when the flow rate is increased) of the valve device in  FIG.  1 A . 
         FIG.  7    is a schematic diagram which shows a valve system according to an embodiment of the present invention, and an application example to a process gas control system of a semiconductor manufacturing apparatus. 
         FIG.  8    is a graph which shows an example of a temporal displacement data V of an operating member, an output (flow rate) Q from a diaphragm valve, and a pressure value when the diaphragm valve is opened and closed periodically. 
         FIG.  9 A  is a flowchart showing an example of processing in a controller. 
         FIG.  9 B  is a flowchart showing an example of drive control process. 
         FIG.  9 C  is a flowchart showing an example of output monitor process. 
         FIG.  9 D  is a flowchart showing an example of output adjustment process. 
         FIG.  9 E  is a flowchart showing another example of the output adjustment process. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Diaphragm Valve 
       FIG.  1 A  is a cross-sectional view showing the configuration of a diaphragm valve  1 , showing a state in which the valve is fully closed.  FIG.  1 B  is a top view of the diaphragm valve  1 ,  FIG.  1 C  is an enlarged longitudinal sectional view of an actuator portion of the diaphragm valve  1 ,  FIG.  1 D  is an enlarged longitudinal sectional view of the actuator portion in a direction 90 degrees different from that of  FIG.  1 C , and  FIG.  1 E  is an enlarged sectional view in a circle A in  FIG.  1 A . In the following explanations, A 1  in  FIG.  1 A  indicates the upward direction, and A 2  indicates the downward direction. 
     The diaphragm valve  1  comprises a housing box  301  provided on a support plate  302 , a valve body  2  installed in the housing box  301 , and a pressure regulator  200  installed in a ceiling portion of the housing box  301 . 
     In  FIGS.  1 A to  1 E,  10    indicates a body,  15  indicates a valve sheet,  20  indicates a diaphragm,  25  indicates a presser adapter,  27  indicates an actuator receiver,  30  indicates a bonnet,  40  indicates an operating member,  48  indicates a diaphragm presser,  50  indicates a casing,  60  indicates a main actuator as a driving mechanism,  70  indicates an adjustment body,  80  indicates an actuator presser,  85  indicates a displacement sensor,  86  indicates a magnetic sensor,  87  indicates a magnet,  90  indicates a coil spring,  100  indicates a piezoelectric actuator as a lift amount adjusting mechanism,  120  indicates a disc spring,  130  indicates a partition wall member,  150  indicates a supply pipe,  160  indicates a limit switch, OR indicates an O-ring as a seal member, and G indicates a compressed air. 
     The body  10  is made of a metal such as stainless steel and defines flow paths  12 ,  13 . The flow path  12  has one end that opens on one side surface of the body  10  as an opening  12   a , and a pipe joint  601  is connected to the opening  12   a  by welding. The other end  12   b  of the flow path  12  is connected to a flow path  12   c  extending in the vertical directions A 1  and A 2  of the body  10 . The upper end portion of the flow path  12   c  is opened at an upper surface side of the body  10 , the upper end portion is opened at a bottom surface of a recess  11  formed on the upper surface side of the valve body  10 , and the lower end portion is opened at the lower surface side of the body  10 . 
     The valve seat  15  is provided around the opening of the upper end portion of the flow path  12   c . The valve seat  15  is made of synthetic resin (PFA, PA, PI, PCTFE, etc.), it is fitted and fixed to a mounting groove provided in the opening periphery of the upper end side of the flow path  12   c . In the present embodiment, the valve seat  15  is fixed in the mounting groove by caulking. 
     The flow path  13  has one end that opens at the bottom surface of the recess  11  of the valve body  10  and the other end that opens as an opening  13   a  on a side surface of the body  10  on the opposite side of the flow path  12 , and a pipe joint  602  is connected to the opening  13   a  by welding. 
     The diaphragm  20  is disposed above the valve seat  15 , defines a flow path communicating the flow path  12   c  and the flow path  13 , and opens and closes the gateway between the flow paths  12  and  13  by moving the central portion thereof up and down to contact to and separate from the valve seat  15 . In the present embodiment, the diaphragm  20  has a spherical shell shape that is an upward convex arc shape in natural state formed by swelling upward a central portion of a metal thin plate of special stainless steel or the like and a nickel-cobalt alloy thin plate. Three such special stainless steel thin plates and one nickel-cobalt alloy thin plate are laminated to form a diaphragm  20 . 
     The diaphragm  20  has an outer peripheral edge portion mounted on a protruding portion formed on the bottom of a recess  11  of the body  10 , and by inserting the lower end portion of the bonnet  30  into the recess  11  and screwing the lower end portion with the screw portion of the body  10 , the diaphragm is pressed toward the protruding portion of the body  10  via a presser adapter  25  made of stainless alloy and is clamped and fixed in an airtight state. The nickel-cobalt alloy thin film can be used in other configurations as the diaphragm which is arranged on the gas contact side. 
     The operating member  40  is a member for operating the diaphragm  20  so that the diaphragm  20  opens and closes the gateway between the flow path  12  and the flow path  13 , and is formed in a substantially cylindrical shape, opened at its upper end side. The operating member  40  is fitted to the inner peripheral surface of the bonnet  30  via an O-ring OR (see  FIGS.  1 C and  1 D ) and is supported movably in the vertical directions A 1  and A 2 . 
     On the lower end surface of the operating member  40 A, a diaphragm presser  48  made of a synthetic resin such as polyimide is mounted and abutted on the upper surface of the central portion of the diaphragm  20 . 
     A coil spring  90  is provided between the upper surface of a flange portion  48   a  formed on the outer peripheral portion of the diaphragm presser  48  and the ceiling surface of the bonnet  30 , and the operating member  40  is constantly biased downward A 2  by the coil spring  90 . Therefore, when the main actuator  60  is not operated, the diaphragm  20  is pressed against the valve seat  15 , and the gateway between the flow path  12  and the flow path  13  is closed. 
     Between the lower surface of the actuator receiver  27  and the upper surface of the diaphragm presser  48 , a disc spring  120  is provided as an elastic member. 
     The casing  50  is composed of an upper casing member  51  and a lower casing member  52 , and a screw on the inner circumference of the lower end portion of the lower casing member  52  is screwed into a screw on the outer circumference of the upper end portion of the bonnet  30 . Further, a screw on the inner circumference of the lower end portion of the upper casing member  51  is screwed into a screw on the outer circumference of the upper end portion of the lower casing member  52 . 
     An annular bulkhead  65  is fixed between the upper end portion of the lower casing member  52  and an opposing surface  51   f  of the upper casing member  51  facing the upper end portion of the lower casing member  52 . Between the inner peripheral surface of the bulkhead  65  and the outer peripheral surface of the operating member  40  and between the outer peripheral surface of the bulkhead  65  and the inner peripheral surface of the upper casing member  51 , sealing is provided by respective O-rings OR. 
     The main actuator  60  has annular first to third pistons  61 ,  62 ,  63 . The first to third pistons  61 ,  62 , and  63  are fitted to the outer peripheral surface of the operating member  40  and are movable in the vertical directions A 1  and A 2  together with the operating member  40 . Sealing is provided by a plurality of O-rings OR between the inner peripheral surfaces of the first to third pistons  61 ,  62 ,  63  and the outer peripheral surface of the operating member  40 , and between the outer peripheral surfaces of the first to third pistons  61 ,  62 ,  63  and the inner peripheral surfaces of the upper casing member  51 , the lower casing member  52 , and the bonnet  30 . 
     As shown in  FIGS.  1 C and  1 D , a cylindrical partition wall member  130  is fixed to the inner peripheral surface of the operating member  40  so as to have a gap GP 1  between the inner peripheral surface of the operating member  40 . The gap GP 1  is sealed by a plurality of O-rings OR 1 ˜OR 3  provided between the outer peripheral surface of the upper end side and the lower end side of the partition wall member  130  and the inner peripheral surface of the operating member  40 , and forms a flow path of a compressed air G as a driving fluid. The flow path formed by the gap GP 1  is concentrically arranged with the piezoelectric actuator  100 . A gap GP 2  is formed between a casing  101  of the piezoelectric actuator  100  and the partition wall member  130 , which will be described later. 
     As shown in  FIG.  1 D , pressure chambers C 1  to C 3  are formed under the lower surfaces of the first to third pistons  61 ,  62 , and  63 , respectively. 
     Flow passages  40   h   1 ,  40   h   2 ,  40   h   3  are formed to penetrate radially through the operating member  40  at positions communicating with the pressure chambers C 1 , C 2 , and C 3 . The flow passages  40   h   1 ,  40   h   2 ,  40   h   3  are each a plurality of flow passages formed at equal intervals in the circumferential direction of the operating member  40 . The flow passages  40   h   1 ,  40   h   2 ,  40   h   3  are each connected to the flow passage formed by the gap GP 1 . 
     The upper casing member  51  of the casing  50  is formed with a flow passage  51   h  which opens at the upper surface and extends in the vertical directions A 1  and A 2  and communicates with the pressure chamber C 1 . A supply pipe  150  is connected to the opening of the flow passage  51   h  via a pipe joint  152 . As a result, the compressed air G supplied from the supply pipe  150  is supplied to the pressure chambers C 1 , C 2 , and C 3  through the flow passages described above. 
     Space SP above the first piston  61  in the casing  50  is connected to the atmosphere through a through hole  70   a  of the adjustment body  70 . 
     As shown in  FIG.  1 C , the limit switch  160  is installed on the casing  50 , and a movable pin  161  penetrates the casing  50  and is in contact with the upper surface of the first piston  61 . The limit switch  160  detects the amount of movement of the first piston  61  (operating member  40 ) in the vertical directions A 1 , A 2  in response to the movement of the movable pin  161 . 
     Displacement Sensor 
     As shown in  FIG.  1 E , the displacement sensor  85  is provided on the bonnet  30  and the operating member  40  and includes a magnetic sensor  86  embedded along the radial direction of the bonnet  30  and a magnet  87  embedded in a portion of the circumferential direction of the operating member  40  so as to face the magnetic sensor  86 . 
     In the magnetic sensor  86 , a wiring  86   a  is led out to the outside of the bonnet  30 , the wiring  86   a  is composed of a feeder line and a signal line, and the signal line is electrically connected to a controller  410  to be described later. Examples of the magnetic sensor  86  include those utilizing a Hall element, those utilizing a coil, those utilizing an AMR element whose resistance value changes depending on the strength and orientation of the magnetic field, or the like, and position detection can be made in non-contact manner by combining with the magnet. 
     The magnets  87  may be magnetized in the vertical directions A 1  and A 2 , or may be magnetized in the radial direction. Further, the magnet  87  may be formed in a ring shape. 
     In the present embodiment, the magnetic sensor  86  is provided on the bonnet  30  and the magnet  87  is provided on the operating member  40 , but it is not limited thereto, and can be changed as appropriate. For example, it is also possible to provide a magnetic sensor  86  on the presser adapter  25  and provide a magnet  87  at a position of a flange portion  48   a  formed on the outer peripheral portion of the diaphragm presser  48  facing thereto. It is preferable to install the magnet  87  on the side movable with respect to the body  10  and install the magnetic sensor  86  on the side not movable with respect to the valve body  10  or the body  10 . 
     Here, the operation of the piezoelectric actuator  100  will be described with reference to  FIG.  2   . 
     The piezoelectric actuator  100  incorporates a laminated piezoelectric element (not shown) in a cylindrical casing  101  shown in  FIG.  2   . The casing  101  is made of a metal such as stainless steel alloy, and the end surface of the hemispherical tip end portion  102  side and the end surface of the base end portion  103  side are closed. By applying a voltage to the laminated piezoelectric element to extend it, the end surface of the casing  101  on the tip end portion  102  side is elastically deformed, and the hemispherical tip end portion  102  is displaced in the longitudinal direction. Assuming that the maximum stroke of the laminated piezoelectric element is 2d, the total length of the piezoelectric actuator  100  becomes L 0  by previously applying a predetermined voltage VO at which the elongation of the piezoelectric actuator  100  becomes d. When a voltage higher than the predetermined voltage VO is applied, the total length of the piezoelectric actuator  100  becomes L 0 +d at the maximum, and when a voltage (including no voltage) lower than the predetermined voltage VO is applied, the total length of the piezoelectric actuator  100  becomes L 0 −d at the minimum. Therefore, it is possible to expand and contract the total length from tip end portion  102  to base end portion  103  in the vertical directions A 1  and A 2 . In the present embodiment, the tip end portion  102  of the piezoelectric actuator  100  is hemispherical, but the present invention is not limited thereto, and the tip end portion may be a flat surface. 
     As shown in  FIGS.  1 A and  1 C , power is supplied to the piezoelectric actuator  100  by a wiring  105 . The wiring  105  is led out to an external controller  410  to be described later through the through hole  70   a  of the adjustment body  70 . 
     As shown in  FIGS.  1 C and  1 D , the vertical position of the base end portion  103  of the piezoelectric actuator  100  is defined by the lower end surface of the adjustment body  70  via the actuator presser  80 . In the adjustment body  70 , a screw portion provided on the outer peripheral surface of the adjustment body  70  is screwed into a screw hole formed in the upper portion of the casing  50 , and by adjusting the position of the adjustment body  70  in the vertical directions A 1  and A 2 , the position of the piezoelectric actuator  100  in the vertical directions A 1  and A 2  can be adjusted. 
     As shown in  FIG.  1 A , the tip end portion  102  of the piezoelectric actuator  100  is in contact with the conical receiving surface formed on the upper surface of the disk-shaped actuator receiver  27 . The actuator receiver  27  is movable in the vertical directions A 1  and A 2 . 
     The pressure regulator  200  has a primary side connected to a supply pipe  203  via a pipe joint  201 , and a secondary side connected to a pipe joint  151  provided at the tip end portion of a supply pipe  150 . 
     The pressure regulator  200  is a well-known poppet valve type pressure regulator, and although a detailed description thereof will be omitted, it reduces the high-pressure compressed air G supplied through the supply pipe  203  to a desired pressure to control the secondary pressure to be a preset adjusted pressure. When the pressure of the compressed air G supplied through the supply pipe  203  fluctuates due to pulsation or disturbance, this fluctuation is suppressed and output to the secondary side. 
     Next, the basic operation of the diaphragm valve  1  will be described referring to  FIGS.  3  and  4   . 
       FIG.  3    shows the valve fully closed state of the diaphragm valve  1 . In the state shown in  FIG.  3   , the compressed air G is not supplied. In this state, the disc spring  120  has already been compressed to some extent and elastically deformed, and the restoring force of the disc spring  120  causes the actuator receiver  27  to be constantly biased toward the upward direction A 1 . Thus, the piezoelectric actuator  100  is also constantly biased toward the upward direction A 1 , and the upper surface of the base end portion  103  is in a state of being pressed against actuator presser  80 . Thus, the piezoelectric actuator  100  receives the compressive force in the vertical directions A 1  and A 2  and is disposed at a predetermined position with respect to the body  10 . Since the piezoelectric actuator  100  is not connected to any member, it is relatively movable in the vertical directions A 1  and A 2 . 
     The number and orientation of the disc spring  120  can be appropriately changed depending on the condition. In addition to the disc spring  120 , other elastic members such as a coil spring or a leaf spring can be used, but the use of a disc spring makes it easy to adjust spring stiffness, stroke, or the like. 
     As shown in  FIG.  3   , when the diaphragm  20  is in contact with the valve seat  15  and the valve is closed, a gap is formed between the regulating surface  27   b  on the lower surface side of the actuator receiver  27  and the contact surface  48   t  on the upper surface side of the diaphragm presser  48  mounted on the operating member  40 . The position of the regulating surface  27   b  in the vertical directions A 1  and A 2  becomes the open position OP in a state in which the opening degree is not adjusted. The distance between the regulating surface  27   b  and the contact surface  48   t  corresponds to the lift amount Lf of the diaphragm  20 . The lift amount Lf is defined by the operating member  40  positioned in the open position OP. The lift amount Lf, defines the opening degree of the valve, that is, the flow rate. The lift amount Lf can be changed by adjusting the position of the adjustment body  70  in the vertical directions A 1  and A 2 . The Diaphragm presser  48  (operating member  40 ) in the state shown in  FIG.  4    is located at the closed position CP with reference to the contact surface  48   t . When the contact surface  48   t  moves to a position in contact with the regulating surface  27   b  of the actuator receiver  27 , that is, to the open position OP, the diaphragm  20  is separated from the valve seat  15  by the lift amount Lf. 
     When compressed air G is supplied into the diaphragm valve  1  through the supply pipe  150 , as shown in  FIG.  4   , a thrust force that pushes the operating member  40  upward A 1  is generated in the main actuator  60 . The pressure of the compressed air G is set to a value sufficient to move the operating member  40  upward A 1  against the biasing force of the downward A 2  acting on the operating member  40  from the coil spring  90  and disc spring  120 . When such compressed air G is supplied, as shown in  FIG.  4   , the operating member  40  moves in the upward direction A 1  while further compressing the disc spring  120 , the contact surface  48   t  of the diaphragm presser  48  abuts the regulating surface  27   b  of the actuator receiver  27 , and the actuator receiver  27  receives a force from the operating member  40  in the upward direction A 1 . This force acts as a force compressing the piezoelectric actuator  100  in the vertical directions A 1  and A 2  through the tip end portion  102  of the piezoelectric actuator  100 . Therefore, the force in the upward direction A 1  acting on the operating member  40  is received by the tip end portion  102  of the piezoelectric actuator  100 , and the movement in the A 1  direction of the operating member  40  is regulated in the open position OP. In this state, the diaphragm  20  is separated from the valve seat  15  by the lift amount Lf described above. 
     Next, an example of the flow rate adjustment of the diaphragm valve  1  will be described with reference to  FIGS.  5  and  6   . 
     First, the displacement sensor  85  described above constantly detects the relative displacement between the body  10  and the magnetic sensor  86  in the states shown in  FIGS.  3  and  4   . The relative positional relationship between the magnetic sensor  86  and the magnet  87  in the valve closed state shown in  FIG.  3    can be set as the origin position of the displacement sensor  85 . The origin position of the displacement data V to be described later is also set to this position. 
     Here, the left side of the center line Ct of  FIGS.  5  and  6    shows a state shown in  FIG.  3   , the right side of the center line Ct shows a state after adjusting the position of the operating member  40  in the vertical directions A 1  and A 2 . 
     When adjusting the flow rate of the fluid in the reducing direction as shown in  FIG.  5   , the piezoelectric actuator  100  is extended to move the operating member  40  downward A 2 . Thus, the lift amount Lf− after adjustment that is the distance between the diaphragm  20  and the valve seat  15  is smaller than the lift amount Lf before adjustment. The extension amount of the piezoelectric actuator  100  may be a deformation amount of the valve seat  15  detected by the displacement sensor  85 . 
     When adjusting the flow rate of the fluid in the increasing direction, as shown in  FIG.  6   , the piezoelectric actuator  100  is shortened to move the operating member  40  upward A 1 . Thus, the lift amount Lf+ after adjustment that is the distance between the diaphragm  20  and the valve seat  15  is larger than the lift amount Lf before adjustment. The reduction amount of the piezoelectric actuator  100  may be the deformation amount of the valve seat  15  detected by the displacement sensor  85 . 
     In the present embodiment, the maximum value of the lift amount Lf of the diaphragm  20  is about 100 to 900 μm, and the adjustment amount by the piezoelectric actuator  100  is about ±20 to 50 μm. 
     The stroke of the piezoelectric actuator  100  cannot cover the lift amount of the diaphragm  20 , but by using the main actuator  60  operated by compressed air G and the piezoelectric actuator  100  together, it is possible to precisely adjust the flow rate with the piezoelectric actuator  100  which has a relatively short stroke, while ensuring the supply flow rate of the diaphragm valve  1  with the main actuator  60  having a relatively long stroke, and it is not necessary to manually adjust the flow rate by the adjustment body  70  or the like. 
     In the present embodiment, the piezoelectric actuator  100  is used as an adjustment actuator utilizing a passive element that converts a given electric power into a force that expands or contracts, but the adjustment actuator is not limited thereto. For example, an electrically driven material made of a compound that deforms in response to a change in an electric field can be used as an actuator. The shape and size of the electrically driven material can be changed by the current or voltage, and the restricted open position of the operating member  40  can be changed. Such an electrically driven material may be a piezoelectric material or an electrically driven material other than a piezoelectric material. When the material is an electrically driven material other than a piezoelectric material, the material may be electrically driven type polymeric material. 
     Electrically driven type polymeric material is also referred to as an electroactive polymer material (Electro Active Polymer: EAP), and includes, for example, an electric EAP driven by an external electric field or a Coulombic force, a nonionic EAP in which a solvent swelling a polymer is flown by an electric field to deform a polymer, an ionic EAP driven by movement of ions and molecules by an electric field, and any one or a combination thereof can be used. 
       FIG.  7    shows an exemplary valve system  400  using the diaphragm valve  1  described above and a semiconductor manufacturing apparatus in which the valve system  400  is applied to a process gas control system. This semiconductor manufacturing apparatus is used, for example, in ALD-based semiconductor manufacturing processes. 
     In  FIG.  7   , the valve system  400  includes a diaphragm valve  1  and a controller  410 . The controller  410  is composed of hardware including a processor (not shown), an input/output circuit, a memory, and the like, a required software, a display, and the like. The controller  410  can output a control signal SG 1  for driving and controlling the main actuator  60  and a control signal SG 2  for driving and controlling the piezoelectric actuator  100  to the diaphragm valve  1 , and is adapted to input a detection signal SG 3  of the displacement sensor  85  provided in the diaphragm valve  1 . Further, the pressure value P to be detected by a pressure sensor  420  provided in the flow path on the primary side of the diaphragm valve  1  is input to the controller  410 . 
     In  FIG.  7 ,  500    indicates a process gas source,  502  indicates a gas box,  504  indicates a tank,  506  indicates a processing chamber, and  508  indicates an exhaust pump. 
     The gas box  502  is an integrated gas system in which various fluid devices such as open-close valve, regulator, and flow rate control device are integrated and housed in a box to supply accurately weighed process gas to the processing chamber  506 . 
     The tank  504  functions as a buffer for temporarily storing the processing gas supplied from the gas box  502 , and the pressure value P of the gas supplied from the tank  504  to the diaphragm valve  1  is controlled to be constant. 
     The processing chamber  506  provides a sealed processing space for forming a film on a substrate by an ALD method. 
     An exhaust pump  508  evacuates the inside of the processing chamber  506 . 
     Here, an outline of the processing of the controller  410  will be described with reference to  FIG.  8   . Controller  410 , as described later, first, periodically opens and closes the diaphragm valve  1  to supply a gas to the processing chamber  506 , second, calculates and monitors the output mass of the gas output for each opening and closing of the diaphragm valve  1 , and third, adjusts the lift amount Lf of the diaphragm  20  so that the output mass of the gas output for each opening and closing of the diaphragm valve  1  follows the target mass. 
       FIG.  8    shows the mass flow rate Q of the gas output from the diaphragm valve  1  and the displacement data V obtained from the displacement sensor  85  when the diaphragm valve  1  is periodically opened and closed, and the horizontal axis represents a time t. The mass flow rate Q is the mass of the gas per unit time output from the diaphragm valve  1 . Incidentally, in  FIG.  8   , P indicates a pressure value, and the pressure value P is the pressure of the primary side of the diaphragm valve  1 . 
     As shown in  FIG.  8   , the diaphragm valve  1  is repeatedly opened and closed at a period TO. A valve opening command is given to the diaphragm valve  1  at an initial time point  0  in the period TO, and a closing command is given to close the diaphragm valve  1  at a time point T 1 . In  FIG.  8   , t 1  indicates a rising region in which the mass flow rate Q is gradually increased, t 2  indicates a valve fully open region in which the mass flow rate Q is constant, t 3  indicates a falling region in which the mass flow rate Q is gradually decreased, t 4  indicates a valve fully closed region in which the gas output is shut off, and the period TO can be divided into each region of t 1  to t 4 . The period TO is, for example, 2.5 seconds, and the total time of the rising region t 1 , the valve fully open region t 2 , and the falling region t 3  is, for example, about 1.5 seconds. 
     Here, the important point is that, since the pressure value P can be regarded to be so constant that the change due to the opening and closing operation of the diaphragm valve  1  is negligible, the relationship of the following equation (1) holds between the mass flow rate Q of the gas and the pressure value P and the displacement data V. 
         Q=V×P   (1)
 
     If the gap between the diaphragm  20  and the valve seat  15  of the diaphragm valve  1  is regarded as a variable orifice whose cross-sectional area changes, the mass flow rate Q of the gas is proportional to the pressure value P. By utilizing the relation of equation (1), the gas outputted by the diaphragm valve  1  can be monitored in real time from the displacement data V obtained from the detected signal SG 3  of the displacement sensor  85  and the pressure value P. Further, by time integrating the mass flow rate Q, it is possible to monitor the output mass of the gas output every opening and closing of the diaphragm valve  1 . In the present embodiment, the pressure value P is fetched into the controller  410 , but when this value is known in advance, it is not necessary to fetch the value into the controller  410 . If the displacement data V, which is time series data, can be obtained, the output mass, which is the time integral of the mass flow rate Q and the mass flow rate Q of the gas, can be monitored. 
     In  FIG.  8   , the height of the flat portion of the valve fully open region t 2  of the displacement data V corresponds to the lift amount Lf of the diaphragm  20 . With the piezoelectric actuator  100  described above, the lift amount Lf can be adjusted up and down within the range indicated by R 1 . Incidentally, when the valve seat  15  is deformed by collision with the diaphragm  20 , the height of the flat portion of the displacement data V gradually decreases. 
     If the gap between the diaphragm  20  and the valve seat  15  of the diaphragm valve  1  is regarded as a variable orifice, the relationship between the cross-sectional area of the variable orifice and the lift amount Lf is different among the plurality of diaphragm valves  1 . Further, the characteristics of the rising region t 1 , the valve fully open region t 2 , and the falling region t 3  are also different among the plurality of diaphragm valves  1 . 
     Therefore, it is necessary to measure the relationship between the value of the lift amount Lf and the value of the cross-sectional area of the variable orifice with each diaphragm valve to create a data table and store the data table in the memory of the controller  410 . Since the value of the cross-sectional area of the variable orifice cannot be measured directly, it is necessary to measure and acquire the relationship data between the value of the lift amount Lf and the value of the mass flow rate Q of the gas for each diaphragm valve  1  in advance. 
     Next, an exemplary process of the controller  410  will be described with reference to the flowcharts shown in  FIGS.  9 A to  9 D . 
     In the controller  410 , in a case of supplying a process gas to the processing chamber  506 , it is determined whether or not the supply should be started (step S 1 ), and when it is determined that the supply should be started (step S 1 :Y), the drive control process of the main actuator  60  is executed (step S 2 ). When it is determined that the supply is not to be started (step S 1 :N), a standby state is maintained. 
     In the drive control process, as shown in  FIG.  9 B , it is determined whether the present time is within the section from the time point  0  to the time point T 1  in the period TO (step S 11 ), and when it is determined that it is within the section (step S 11 :Y), the control signal SG 1  output to the diaphragm valve  1  (valve opening command signal) is turned on (step S 12 ), and when it is determined that it is outside the section (step S 11 :N), the control signal SG 1  (valve opening command signal) is turned off (step S 13 ). With such a process, the diaphragm valve  1  is opened and closed periodically in a period TO, and the gas is output to the gas processing chamber  506  through the diaphragm valve  1 . 
     Next, the output monitoring process shown in  FIG.  9 A  is performed (step S 3 ). In the output monitoring process, as shown in  FIG.  9 C , it is determined whether the current time is in a section that is any of the rising region t 1 , the valve fully open region t 2 , and the falling region t 3  (step S 21 ), and when it is determined to be within the section (step S 21 :Y), the detected signal SG 3  of the displacement sensor  85  is sampled (step S 22 ) and stored as the displacement data V (step S 23 ). Mass flow rate Q of the gas is calculated using the sampled displacement data V (step S 24 ), and the mass flow rate Q is time integrated to calculate the output mass TQ of the gas (step S 25 ). In step S 21 , when it is determined that the current time is outside the section described above, that is, in the valve fully closed region t 4  (step S 21 :N), the process is terminated. Calculated mass flow Q and the output mass TQ can be graphically displayed on a display or the like. 
     Next, the output adjustment process  1  shown in  FIG.  9 A  is performed (step S 4 ). 
     In the output adjustment process  1 , as shown in  FIG.  9 D , it is determined whether the current time is in the valve fully closed region t 4  (step S 31 ), and when the current time is determined to be in the valve fully closed region t 4  (step S 31 :Y), the output mass TQ calculated in step S 25  is obtained (step S 32 ), and the deviation E between the output mass TQ and the target mass RQ is calculated (step S 33 ). The target mass RQ is the ideal mass of the gas output in one opening and closing operation of the diaphragm valve  1 . In step S 31 , if the current time is determined to be outside the section of the valve fully closed region t 4  (step S 31 :N), the process is terminated. 
     Next, it is determined whether the deviation E is larger than the threshold value Th (step S 34 ), and when the deviation E is determined to be larger than the threshold value Th (step S 34 :Y), the above-described relationship data between the above-described value of the lift amount Lf and the mass flow rate Q of the gas is referred to determine the lift adjustment amount for adjusting the lift amount Lf for canceling the deviation E (step S 35 ). The control signal SG 2  corresponding to the calculated lift adjustment amount is output to the piezoelectric actuator  100  (step S 36 ). Thus, within the section of the valve fully closed region t 4 , the lift amount Lf is changed, and consequently, the mass flow rate Q when the diaphragm valve  1  is opened and closed in the next cycle is modified, and the output mass TQ follows the target mass RQ. When it is determined in step S 34  that the deviation E is smaller than the threshold value Th (step S 34 :N), the process is terminated. 
     Referring back to  FIG.  9 A , after step S 4 , it is determined whether or not the supplying of the gases should be terminated (step S 5 ), and when it is determined that the supplying of the gases should be terminated (step S 5 :Y), the processing is terminated, and when it is determined that the supplying of the gases should not be terminated (step S 5 :N), the processing of steps S 2  to S 4  is repeatedly executed. Note that the processes of steps S 2  to S 5  in  FIG.  9 A  are executed at predetermined sampling times. 
     As described above, according to the present embodiment, it is possible to monitor in real time the mass flow rate Q and the output mass TQ of the gas output from the diaphragm valve  1  each time the valve is opened and closed. In addition, since the lift amount Lf can be adjusted so that the deviation E between the output mass TQ and the target mass RQ is canceled based on the output mass TQ obtained by one opening and closing operation (one cycle) of the diaphragm valve  1 , the output mass of the gas supplied from the diaphragm valve  1  which is opened and closed periodically can be more precisely controlled. 
     In the output adjustment process  1  shown in  FIG.  9 D , based on the output mass TQ obtained by one opening and closing operation of the diaphragm valve  1 , the lift amount Lf in the next opening and closing operation of the diaphragm valve  1  is adjusted, but the present invention is not limited thereto. 
     In the output adjustment process  2  shown in  FIG.  9 E , the adjustment lift amount is determined based on the output mass calculated during one opening and closing operation of the diaphragm valves  1 , and the lift amount Lf is adjusted during the opening and closing operation of the one. 
     In the output adjustment process  2 , as shown in  FIG.  9 E , it is determined whether the current time is in the falling region t 3  (step S 41 ), and when it is determined that the current time is in the falling region t 3  (step S 41 :Y), a predicted output mass PTQ is calculated (step S 42 ). When it is determined that the current time is not in the falling region t 3  (step S 41 :N), the process ends. 
     The predicted output mass PTQ is based on, for example, the change characteristics of the mass flow rate Q (displacement data V) of the rising region t 1  and the valve fully open region t 2  and the falling region t 3  up to the present time (that is, up to the middle of the falling region t 3 ), and is a predicted output mass to be output when the falling region t 3  is finally completed. For example, the predicted output mass PTQ output when the falling region t 3  is finally completed can be calculated from the change characteristics of the output mass up to the present time and the mass flow rate Q of the falling region t 3  obtained up to the present time. Incidentally, it is not limited to this method, and it is sufficient that the final output mass can be predicted by utilizing the displacement data V obtained during one opening and closing operation of the diaphragm valve  1 . 
     Next, a deviation E between the predicted output mass PTQ and the target mass RQ is calculated (step S 43 ). The target mass RQ is an ideal mass output in one opening and closing operation. 
     Then, it is determined whether or not the deviation E is larger than the threshold value Th (step S 44 ), and if the deviation E is determined to be larger than the threshold value Th (step S 44 :Y), the lift adjustment amount for adjusting the lift amount Lf of the diaphragm  20  for canceling the deviation E is determined with reference to the above-described relational data between the lift amount Lf and the mass flow rate Q (step S 45 ). The control signal SG 2  corresponding to the calculated lift adjusting amount is output to the piezoelectric actuator  100  (step S 46 ). 
     Thus, the lift amount Lf of the diaphragm  20  is changed within the section of the falling area t 3 , that is, in the middle of one opening and closing operation of the diaphragm valve  1 . As a result, the mass flow rate Q and the output mass TQ is corrected in real time within the same opening and closing operation. As a result, the output mass for each opening and closing of the diaphragm valve  1  can be more precisely controlled. The lift amount Lf of the diaphragm  20  may be changed within the section of the rising region t 1  and the valve fully open region t 2 . 
     If it is determined in step S 44  that the deviation E is smaller than the threshold Th (step S 44 :N), the process is terminated. 
     In the above embodiment, a displacement sensor including a magnetic sensor and a magnet has been exemplified, but the displacement sensor is not limited thereto, and a non-contact type position sensor such as an optical position detection sensor can be adopted. 
     In the above embodiment, the piezoelectric actuator  100  is used to adjust the lift amount, but the present invention is not limited thereto, and it is also possible to adjust the lift amount Lf manually while monitoring the output of the diaphragm valve  1 . 
     Note that the present invention is not limited to the above-described embodiment. Various additions, modifications, and the like can be made by those skilled in the art within the scope of the present invention. For example, in the above application example, the case in which the flow rate control device of the present invention is used in the semiconductor manufacturing process by the ALD method has been exemplified, but the present invention is not limited thereto, and can be applied to, for example, an atomic layer etching method or the like. 
     REFERENCE SIGNS LIST 
     
         
           1 : Diaphragm valve 
           2 : Valve body 
           10 : Body 
           11 : Recess 
           12 : Flow path 
           12   a : Opening 
           12   b : The other end 
           12   c , 13 : Flow path 
           13   a : Opening 
           15 : Valve seat 
           20 : Diaphragm 
           25 : Presser adapter 
           27 : Actuator receiver 
           27   b : Regulating surface 
           30 : Bonnet 
           40 : Operating member 
           48 : Diaphragm presser 
           48   a : Flange portion 
           48   t : Contact surface 
           50 : Casing 
           51 : Upper casing member 
           51   f : Opposing surface 
           51   h : Flow passage 
           52 : Lower casing member 
           60 : Main actuator 
           70 : Adjustment body 
           80 : Actuator presser 
           85 : Displacement sensor 
           86 : Magnetic sensor 
           86   a : Wiring 
           87 : Magnet 
           90 : Coil spring 
           100 : Piezoelectric actuator 
           101 : Casing 
           102 : Tip end portion 
           103 : Base end portion 
           105 : Wiring 
           120 : Disc spring 
           130 : Partition wall member 
           150 : Supply pipe 
           151 , 152 : Pipe joint 
           160 : Limit switch 
           161 : Movable pin 
           200 : Pressure regulator 
           201 : Pipe joint 
           203 : Supply pipe 
           301 : Housing box 
           302 : Support plate 
           400 : Valve system 
           410 : Controller 
           420 : Pressure sensor 
           502 : Gas box 
           504 : Tank 
           506 : Processing chamber 
           508 : Exhaust pump 
           601 , 602 : Pipe joint 
         E: Deviation 
         G: Compressed air 
         Lf: Lift amount 
         OP: Open position 
         P: Pressure value 
         PTQ: Predicted output mass 
         Q: Mass flow rate 
         RQ: Target mass 
         TO: Period 
         TQ: Output mass 
         Th: Threshold 
         V: Displacement data 
         t 1 : Rising region 
         t 2 : Valve fully open region 
         t 3 : Falling region 
         t 4 : Valve fully closed region