JPH10252942A - Vacuum pressure control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum pressure control system in which the required time to regulate the pressure in a vacuum container from the high vacuum pressure to the low vacuum pressure, and the whole size is miniaturized. SOLUTION: A vacuum control valve 10 is provided with a valve disk 40, a valve seat 45 and a pilot valve 31. The gas pressure to be regulated by an electropneumatic proportional valve 56 and two solenoid valves 54, 55 is fed to a pressurization chamber 33b of the pilot valve 31. A controller 51 controls the valves 54-56 in order to rapidly bring the detected pressure by a pressure sensor 25 close to the prescribed value by changing the opening of the vacuum control valve 10. In the continuous first and second controls, the controller 51 operates the solenoid valves 54, 55 to rapidly release the gas pressure from the pressurization chamber 33b, and controls the electropneumatic proportional valve 56 to regulate the vacuum pressure to the prescribed value when the detected opening by a potentiometer 37 reaches the prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum pressure control system which adjusts and maintains a predetermined vacuum pressure in a vacuum vessel. For example, the present invention relates to a vacuum pressure control system applied to a single-wafer apparatus that processes semiconductor wafers one by one in a semiconductor manufacturing process, and adjusts the inside of the vacuum vessel to a predetermined vacuum pressure.

[0002]

2. Description of the Related Art Conventionally, there is a vacuum pressure control system in which the inside of a vacuum vessel is adjusted to a predetermined vacuum pressure and held. FIG. 13 discloses an example of this system.

This system has a vacuum chamber 81 which is a vacuum container. In the chamber 81, a plurality of semiconductor wafers 82 are arranged in a stepped manner. The chamber 81 has an inlet 83 and an outlet 84. A supply source for supplying a process gas into the chamber 81 and a supply source for supplying a nitrogen gas for purging the process gas supplied into the chamber 81 are connected to the inlet 83 via a pipe 85, respectively. Is done.

An outlet 84 is connected to an inlet of a pilot operation valve 86 formed of a bellows type poppet valve via a pipe 87. The outlet of the operation valve 86 is connected to a vacuum pump 89 via a pipe 88. The operation valve 86 has both pipes 8
7, 88 is selectively opened and closed. In the middle of the pipe 88, an opening proportional valve 90 whose opening is adjusted in a butterfly manner is provided.

The proportional valve 90 has a support shaft and a disc-shaped valve element (both not shown) which is rotated about the support shaft. The outer diameter of the valve body is substantially the same as the inner diameter of the pipe 88. The support shaft is rotated by a step motor 91. The opening of the proportional valve 90 is changed by rotating the valve body by the rotation of the support shaft. The pipe 87 is provided with a pressure sensor 92 for detecting a vacuum pressure in the chamber 81. Piping 8
Between the pressure sensor 7 and the pressure sensor 92 for shutting off the transmission of pressure to the sensor 92 during maintenance.
3 are provided. The controller 94 takes in the detection value of the pressure sensor 92. The controller 94 includes the chamber 81
The motor 91 is controlled in order to adjust the opening of the proportional valve 90 so that the vacuum pressure in the inside becomes a predetermined value.

In a semiconductor manufacturing process, the chamber 81
Is supplied with a process gas from a supply source. The controller 94 controls the motor 91 to increase the opening of the proportional valve 90 when the vacuum pressure in the chamber 81 becomes higher than the target value toward the atmospheric pressure. Thus, the amount of air sucked by the vacuum pump 89 increases. The controller 94 controls the motor 91 to reduce the opening of the proportional valve 90 when the vacuum pressure in the chamber 81 becomes lower than the target value toward the absolute vacuum pressure.
Thus, the amount of air sucked by the vacuum pump 89 decreases.

However, with a butterfly valve such as the proportional valve 90, the flow of air sucked from the chamber 81 to the vacuum pump 89 cannot be completely shut off. For this reason, in the above system, a separate shutoff valve such as the pilot operated valve 86 needs to be connected in series to the proportional valve 90 in order to completely shut off the flow of the suction air. Here, the shutoff valve has a function of completely shutting off the flow of the suction air in addition to a function of completely shutting off the flow of the suction air, in addition to a function of immediately closing when the power supply to the system is stopped. Required. Therefore, a cylinder type valve having a different structure from the butterfly type valve is used as the pilot operation valve 86.

On the other hand, it is assumed that the flow of the suction air is completely shut off only by the butterfly type proportional valve 90. In this case, O is placed between the valve body and the inner wall of the pipe 88.
It is also conceivable to interpose a packing such as a ring. However, in the above-described semiconductor manufacturing apparatus, the product of the process gas passing through the proportional valve 90 may precipitate on the surface of the packing. Therefore, this product becomes a resistance and the proportional valve 9
The torque load required to rotate the zero valve element becomes excessive. For this reason, the proportional valve 90 is unlikely to be fully closed, and the flow of the suction air may not be completely shut off by the proportional valve 90.

On the other hand, when the inside of the chamber 81 is evacuated, a large amount of process gas may remain in the chamber 81. In this case, when the opening of the proportional valve 90 becomes excessive, a large amount of process gas is rapidly sucked from the chamber 81 to the vacuum pump 89. For this reason,
An air current may be generated in the chamber 81, and particles adhering to the wall surface may be wound up. When the chamber 81 is made of quartz, the chamber 81
When the pressure inside the chamber suddenly changes from the atmospheric pressure to the vacuum pressure, the chamber 81 may be damaged due to the pressure change. Therefore, in order to eliminate such damage, the inside of the chamber 81 must be slowly evacuated.

It is rare that all the wound particles are sucked by the vacuum pump 89, and the particles may be excessively attached to the wafer 82. Therefore, in order to prevent the particles from being rolled up, it is necessary to suck the process gas in the chamber 81 little by little first. For this purpose, first, the proportional valve 90 needs to be opened slightly, and the motor 91 needs to be controlled so that the state is maintained in a stable manner.

However, the butterfly type proportional valve 90 has a gap of about 0.5 mm between the outer peripheral edge of the valve body and the inner wall of the valve due to its structure. For this reason, even if the valve element is fully closed, the pressure is sucked from the gap with considerable force. Also, in the butterfly type proportional valve 90, in a small opening range, the opening degree tends to largely change even if the valve element is slightly rotated. For this reason, it is difficult for the vacuum pump 89 to gradually remove the process gas from the chamber 81.

Therefore, in the above system, the bypass valve 95 and the shutoff valve 96 connected in series with each other are provided in parallel with the operation valve 86. Here, the opening degree of the bypass valve 95 is set to be small in advance. Therefore, the operation valve 86
Is closed, the proportional valve 90 is opened, and the shut-off valve 96 is opened, the space between the vacuum pump 89 and the chamber 81 is passed through a narrow flow path. As a result, the process gas in the chamber 81 is gradually sucked into the vacuum pump 89. These controls are performed by the controller 94 based on the value detected by the pressure sensor 92.
This is performed by controlling 95 and 96.

[0013]

However, the conventional vacuum pressure control system described above may have the following problems.

That is, in the conventional system, the opening of the butterfly type proportional valve 90 is adjusted to adjust the vacuum pressure. In the proportional valve 90, even if the flow of the suction air toward the vacuum pump 89 is reduced at a high speed, it takes a certain time (for example, about 10 seconds) until the valve element is fully closed so that the flow is minimized. ) Is required. This is due to the fact that the rotation speed of the motor for driving the valve element cannot be so high corresponding to shutting off the vacuum flow or the process gas at high speed. That is, the response of the proportional valve 90 is not sufficient to shut off the vacuum flow or the process gas at a high speed. Therefore, the time required to adjust the inside of the chamber 81 from a high vacuum pressure to a low vacuum pressure becomes longer.
This is the same when the proportional valve 90 is switched from the fully open state to a target opening degree in order to adjust the inside of the chamber 81 from a high vacuum pressure to a lower vacuum pressure.

Such a response performance of the proportional valve 90 is particularly problematic in, for example, a vacuum chamber applied to a single-wafer apparatus. The single-wafer apparatus is an apparatus configured to process semiconductor wafers one by one in a semiconductor manufacturing process. The single-wafer apparatus has a plurality of vacuum chambers. One wafer is placed in each chamber, and supply and purging of a process gas are performed under control of a vacuum pressure.
After the process, the wafer is taken out of the chamber.
A series of steps performed in a plurality of chambers are slightly shifted with respect to time. Therefore, from multiple chambers,
One wafer is sequentially taken out. In order to improve the process capability of such a single-wafer apparatus, it is necessary to shorten the tact time required for a series of processes in each chamber. In the conventional system, it is difficult to reduce the tact time due to the limitation due to the insufficient responsiveness of the proportional valve 90.

In addition, in the conventional system, the proportional valve 90
In addition, a pilot operation valve 86, a bypass valve 95, and a shutoff valve 96 are required. Therefore, each of the valves 86, 95, 9
6 and the pipes 87 and 88 have more connections, and the pipe 8
There is an increased possibility that particles will be mixed into 7, 88. Furthermore, the equipment of the system becomes large, and the process becomes complicated. For this reason, there is a problem as a semiconductor manufacturing system that requires a reduction in the size of each facility.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to make it possible to reduce the time required for adjusting the inside of a vacuum vessel from a high vacuum pressure to a low vacuum pressure. To provide a vacuum pressure control system capable of making the whole compact.

Still another object of the present invention is to provide a vacuum pressure control system which can precisely adjust a vacuum pressure to a target value.

[0019]

According to a first aspect of the present invention, there is provided a vacuum vessel, a vacuum pump for sucking a gas supplied into the vacuum vessel,
A pipe for connecting the vacuum vessel and the vacuum pump, a vacuum control valve provided on the pipe to change the vacuum pressure in the vacuum vessel by changing its own opening, and a vacuum control valve in the vacuum vessel. A vacuum having a pressure sensor for detecting a vacuum pressure, and a control device for controlling an opening of a vacuum control valve based on the detected vacuum pressure so that the vacuum pressure in the vacuum container becomes a predetermined value. In the pressure control system, the vacuum control valve has a valve body, a valve seat, and a pilot valve,
The valve body includes a tapered surface tapered on its outer periphery, and when the valve body moves along the central axis of the hole of the valve seat, the size of the gap between the valve seat and the tapered surface changes to change the vacuum control valve. The pilot valve is supplied with the gas pressure adjusted by the servo valve to move the valve body, and the control device changes the opening of the vacuum control valve. Operates to adjust the gas pressure supplied to the pilot valve by controlling the servo valve to adjust the vacuum pressure to a predetermined value, and to quickly release the gas pressure supplied to the pilot valve from the same valve. The quick exhaust valve to be controlled, and the control device controls the quick exhaust valve in order to quickly reduce the opening of the vacuum control valve by quickly releasing the gas pressure from the pilot valve. I do.

According to the configuration of the first aspect of the present invention, when the vacuum pump operates, the gas in the vacuum vessel is sucked by the vacuum pump, and the inside of the vacuum vessel is evacuated. Here, when the opening of the vacuum control valve changes, the amount of gas sucked from the inside of the vacuum container to the vacuum pump is adjusted, and the vacuum pressure in the vacuum container changes. This vacuum pressure is detected by a pressure sensor.

The control device controls the opening of the vacuum control valve based on the detected vacuum pressure so that the vacuum pressure in the vacuum vessel becomes a predetermined value. Here, in the vacuum control valve,
A valve body including a tapered surface on its outer periphery moves along the central axis of the hole in the valve seat. The opening degree of the vacuum control valve is changed by moving the valve body by the pilot valve and changing the size of the gap between the valve seat and the tapered surface. To move the valve element, the pilot valve is supplied with a gas pressure regulated by a servo valve. The controller adjusts the gas pressure supplied to the pilot valve by controlling the servo valve. Thereby, the opening degree of the vacuum control valve changes, and the vacuum pressure is adjusted. The quick exhaust valve operates to quickly release gas pressure supplied to the pilot valve from the pilot valve. The controller controls the quick exhaust valve.

Therefore, when a certain amount of gas pressure is supplied to the pilot valve, that is, when the vacuum control valve is opened to some extent, the control device controls the quick exhaust valve. As a result, the gas pressure is quickly released from the pilot valve, the valve body of the vacuum control valve is quickly moved, and the opening thereof is quickly reduced. As a result, the amount of gas sucked into the vacuum pump from the inside of the vacuum container is quickly reduced, and the vacuum pressure in the vacuum container is quickly reduced.

In order to achieve the above object, the second invention according to the second invention is different from the first invention in that a rapid operation is performed to quickly release the gas pressure supplied to the pilot valve from the pilot valve. The exhaust valve, the opening sensor for detecting the opening of the vacuum control valve, and the control device perform the first control to change the opening of the vacuum control valve to quickly bring the vacuum pressure close to a predetermined value. And the second control is executed continuously. The first control is to operate a quick exhaust valve to quickly release the gas pressure supplied to the pilot valve from the pilot valve. Is that the servo valve is controlled to adjust the vacuum pressure to a predetermined value when the detected opening reaches a predetermined value.

According to the configuration of the second invention, unlike the first invention, the opening of the vacuum control valve is detected by the opening sensor. Here, the control device continuously executes the first and second controls in order to move the valve body and change the opening thereof to bring the vacuum pressure close to a predetermined value. That is,
As a first control, the control device first operates the quick exhaust valve in order to quickly release the gas pressure from the pilot valve. Thereafter, when the detected opening reaches a predetermined value, the control device adjusts the vacuum pressure to a predetermined value.
Control the servo valve.

Therefore, when the vacuum control valve is opened to some extent, the control device executes the first and second controls continuously. As a result, the gas pressure is quickly released from the pilot valve first, and the opening degree of the vacuum control valve is rapidly reduced. As a result, the amount of gas sucked into the vacuum pump from the inside of the vacuum container is quickly reduced, and the vacuum pressure in the vacuum container is quickly reduced. Thereafter, when the opening of the vacuum control valve reaches a predetermined value, the servo valve is controlled, the gas pressure supplied to the pilot valve is adjusted, and the opening of the vacuum control valve is adjusted. Thereby, the reduced vacuum pressure is further adjusted toward the predetermined value.

In order to achieve the above object, a third aspect of the present invention is directed to the third aspect of the present invention, wherein the pilot valve moves in the hollow cylinder chamber and the cylinder chamber. The invention is intended to include a piston having an inner peripheral end fixed to the piston and a bellofram fixed to an inner wall of the cylinder chamber at an outer peripheral end.

According to the configuration of the third aspect, in addition to the operation of the first aspect or the second aspect, in the pilot valve, the piston is fixed to the inner wall of the cylinder via the bellofram. For this reason, the movement resistance generated between the piston and the cylinder inner wall is reduced. Therefore, the movement and stop of the piston with respect to the cylinder chamber wall become easy, and the position adjustment becomes easy.

In order to achieve the above object, according to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the quick exhaust valve is selectively opened and closed by energization. A first solenoid valve that operates and a second solenoid valve, wherein the first solenoid valve switches the communication of the pilot valve to the servo valve or the second solenoid valve, and the second solenoid valve is a source of gas pressure. Or switching the communication of the first solenoid valve to the exhaust pipe for releasing the gas pressure, and the control device switches to at least one of the first solenoid valve and the second solenoid valve to operate the quick exhaust valve. It is intended to include supplying a signal.

According to the configuration of the fourth aspect of the invention, in addition to the operation of any one of the first to third aspects, the first solenoid valve receives a switching signal from the control device and receives the switching signal. The communication of the pilot valve with the servo valve or the second solenoid valve is switched in accordance with. The second solenoid valve receives a switching signal from the control device, and switches the communication of the first solenoid valve to the gas pressure supply source or the exhaust pipe according to the switching signal. Thereby, the flow of the pilot valve to the servo valve, the supply source of the gas pressure or the exhaust pipe is switched, and the supply and discharge of the gas pressure to the pilot valve are adjusted.

In order to achieve the above object, a fifth aspect of the present invention is directed to the fifth aspect of the present invention, in any one of the first to fourth aspects, wherein the servo valve comprises a time interval corresponding to a pulse frequency. The solenoid valve for air supply is connected between a supply source for gas pressure and a pilot valve, and is connected between an exhaust pipe and a pilot valve for releasing gas pressure. The control device controls the opening degree of the vacuum control valve by supplying a pulse signal to the supply air valve and the discharge electromagnetic valve. It is intended to include.

According to the configuration of the fifth aspect, in addition to the function of any one of the first to fourth aspects, in the servo valve, the solenoid valve for supplying air is provided with a pulse signal from the control device. In response to this, the switching operation is performed at a time interval corresponding to the pulse frequency of the pulse signal. Thereby, the supply of the gas pressure from the supply source to the pilot valve is adjusted. The exhaust electromagnetic valve receives a pulse signal from the control device and opens and closes at a time interval corresponding to the pulse frequency. As a result, the gas pressure released from the pilot valve to the exhaust pipe is adjusted.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a vacuum pressure control system according to the present invention will be described in detail with reference to the drawings. In this embodiment, a vacuum pressure control system is embodied in a semiconductor manufacturing apparatus, in particular, a single-wafer apparatus.

FIG. 3 is a schematic configuration diagram showing the single-wafer apparatus 1. The apparatus 1 simultaneously processes a plurality of wafers 2 in a semiconductor manufacturing process. The apparatus 1 includes a transfer robot 3 and a plurality of vacuum chambers 4A and 4
B, 4C, 4D, and 4E. Multiple chambers 4A
4E are arranged radially around the robot 3. The robot 3 and the plurality of chambers 4A to 4E are housed in one closed room 5. The inside of the room 5 is always set to a vacuum state. Some of the plurality of chambers 4A to 4E are load lock chambers for loading, and one or two chambers are provided in one apparatus. When two load lock chambers are provided, one of them is a chamber dedicated to the entrance for loading the wafer 2, and the other one is a chamber dedicated to the exit for unloading the wafer 2. Each of the chambers 4A to 4E has a gate 6 arranged at a position facing the robot 3. Each gate 6 is selectively opened and closed. When each gate 6 is opened, the robot 3 moves the wafer 2 in and out of the corresponding chambers 4A to 4E.

A gas supply pipe 7 and a gas discharge pipe 8 are connected to each of the chambers 4A to 4E.
The supply pipe 7 is connected to a process gas supply source (not shown) and a purge nitrogen gas supply source (not shown), respectively. A vacuum pump 9 (shown in FIG. 4) is connected to the discharge pipe 8. A vacuum control valve 10 composed of a pilot operation valve is provided on each discharge pipe 8. In the semiconductor manufacturing process, one wafer 2 is accommodated in each of the processing chambers 4A to 4D. In each of the processing chambers 4A to 4D, the supply of the process gas and the purging thereof are performed under the condition that the vacuum pressure is controlled. After the process in each of the chambers 4A to 4D, each wafer 2 is moved by the robot 3 to each of the chambers 4A to 4D.
4D and temporarily stored in the loading chamber 4E.

The loading chamber 4E further has a gate 11 different from the gate 6. When the gate 11 is opened, the wafer 2 is carried out of the chamber 4E to the outside of the room 5. The unloaded wafer 2 is mounted on a carrier 12 and transported to a predetermined position by a conveyor 13. A series of steps performed in the plurality of chambers 4A to 4E have slightly different start times. Therefore, one wafer 2 is sequentially processed in each of the processing chambers 4A to 4D, and the processed wafer 2 is sequentially carried out of the room 5 through the chamber 4E. In order to improve the process capability of such a single-wafer apparatus 1, it is necessary to shorten the tact time required to execute a series of processes in each of the processing chambers 4A to 4E.

In this embodiment, each of the chambers 4A to 4A
One vacuum pressure control system is provided independently for each of E. FIG. 4 schematically shows the configuration of one vacuum control system corresponding to each chamber 4A. This configuration is similar to that of the other chambers 4B to 4D. Therefore, the control system will be described below with the chamber 4A as a representative.

The wafer 2 is placed on the table 21 in the chamber 4A. The chamber 4A has an inlet 22 and an outlet 23. A supply source of a process gas is connected to the inlet 22 via the pipe 7. Similarly, a supply source of nitrogen gas for purging the process gas supplied to the chamber 4A is connected to the inlet 22 via the pipe 7.

The outlet 23 is connected to the inlet 10 of the vacuum control valve 10.
a is connected via the pipe 8. An outlet 10 b of the vacuum control valve 10 is connected to a vacuum pump 9 via a pipe 8.
A pressure sensor 25 is connected to the outlet 23 via a shutoff valve 24. In the present embodiment, as the pressure sensor 25,
A capacitance manometer is used.

FIGS. 5 and 6 are sectional views of the vacuum control valve 10. FIG. FIG. 5 shows a state in which the control valve 10 is closed, and FIG. 6 shows a state in which the control valve 10 is fully opened. The vacuum control valve 10 includes a pilot valve 31 and a bellows-type poppet valve 32 which are assembled vertically.

The pilot valve 31 has a single-acting pneumatic cylinder 33 having a hollow cylinder chamber, and a piston 34 movably attached to the cylinder chamber. The piston 34 is urged downward by a return spring 35. A slide lever 36 extending upward is provided at the upper end of the piston 34.

A potentiometer 37 as an opening sensor is mounted outside the cylinder 33. The potentiometer 37 has a built-in variable resistor (not shown).
The upper end of the lever 36 is connected to a variable resistor. When the lever 36 moves up and down integrally with the piston 34, the value of the variable resistance changes. The potentiometer 37 outputs the resistance value as a value correlated with the position of the piston 34 in the vertical direction.

On the lower surface of the piston 34, a bellofram 38 is provided.
Is provided. The inner peripheral end of the bellofram 38 is a piston 3
Fixed to 4. The outer peripheral end of the bellofram 38 is fixed to the inner wall of the cylinder chamber. Velofram 38 is extremely thin and structurally formed by coating rubber on strong polyester, tetron cloth or the like. The bellofram 38 has a long deformation stroke and a deep turn. The bellows diaphragm 38 is a diaphragm having a cylindrical shape, the effective pressure receiving area of which is kept constant during deformation. The cylinder chamber is
It includes an atmospheric chamber 33a and a pressurizing chamber 33b vertically divided by a piston 34 and a bellofram 38. The upper atmosphere chamber 33a accommodates a return spring 35, and air is introduced from an atmosphere port (not shown). The lower pressurizing chamber 33b is provided with a supply source (not shown) through a pressurizing port (not shown).
Compressed air is introduced from.

At the center of the piston 34, a piston rod 39 extending downward is fixed. The poppet valve 32 includes a rod 39, a valve body 40, and a casing 41. The valve body 40 is fixed to the lower end of the rod 39. Those two members 3
9 and 40 are accommodated in a casing 41. Casing 4
Reference numeral 1 denotes a cylindrical shape, and the above-described inlet 10a and outlet 10b
Having. A bellows 42 is provided on the upper surface of the valve body 40. The bellows 42 is arranged so as to include the rod 39.

7 and 8 show the structure of the valve body 40 in detail.
FIG. 7 shows a state of the valve body 40 when the vacuum control valve 10 is closed. FIG. 8 shows the state of the valve body 40 when the opening of the vacuum control valve 10 is medium.

The valve body 40 is connected to the main body 4 connected to the rod 39.
0a and an attachment portion 40b to which the O-ring 43 is attached.
, A stainless steel valve body 44, and a mounting portion 40c to which the stainless steel valve body 44 is mounted. In this embodiment, the material of the stainless steel valve body 44 is SUS316.
L is used. The stainless steel valve element 44 has a tapered tapered surface 44a on its outer periphery and a straight surface 4
4b. In the vicinity of the inlet 10a of the casing 41, a valve seat 45 corresponding to the valve body 40 is provided. The valve seat 45 is set on the inner peripheral surface of a cylinder provided at the inlet 10a. The valve body 40 moves along the central axis of the hole of the valve seat 45. The O-ring 43 suppresses fluid leakage when the valve body 40 is pressed downward so that the straight surface 44b contacts the valve seat 45, that is, when the vacuum control valve 10 is fully closed. In the present embodiment, the angle θ of the tapered surface 44a is set to “3 °”.

As shown in FIG. 8, when the tapered surface 44a of the stainless steel valve element 44 moves vertically along the center line of the hole of the valve seat 45, the gap between the tapered surface 44a and the valve seat 45 is increased. Area changes. The area of this gap corresponds to the opening of the vacuum control valve 10. As shown in FIG.
Is in contact with the upper end surface of the cylinder constituting the valve seat 45,
The ring 43 is pressed against the upper end surface of the cylinder, and the leakage of fluid between the valve body 40 and the valve seat 45 is completely shut off. That is, when the vacuum control valve 10 is fully closed, the valve body 40 and the valve seat 45
And the leakage of fluid between them is suppressed.

When the piston 34 moves up and down, the valve element 40 moves up and down via the rod 39. This allows
The opening of the vacuum control valve 10 changes. Therefore, the potentiometer 37 measures the position of the piston 34 in the vertical direction, that is, the position of the valve body 40 in the vertical direction, that is, the opening of the vacuum control valve 10, and outputs the measured value.

FIG. 1 shows a configuration related to control in the vacuum pressure control system of the present embodiment. This control system includes a controller 51 as a control device and an air pressure control unit 5.
2, a vacuum control valve unit 53, and a pressure sensor 25.

The vacuum control valve section 53 includes the vacuum control valve 10, the potentiometer 37 and its amplifier 63. The air pressure control unit 52 has a first solenoid valve 54, a second solenoid valve 55, an electropneumatic proportional valve 56 as a servo valve of the present invention, a position control circuit 57, and a pulse drive circuit 58. The first solenoid valve 54 and the second solenoid valve 55 constitute a quick exhaust valve of the present invention.

The first port 54a of the first solenoid valve 54
Is connected to an electropneumatic proportional valve 56. The third port 55c of the second solenoid valve 55 is connected to the second port 54b of the first solenoid valve 54. The third port 54c of the first solenoid valve 54 is connected to the pressurizing chamber 33b of the vacuum control valve 10. The first port 55a of the second solenoid valve 55 is connected to a compressed air supply source (not shown). Second solenoid valve 5
The fifth second port 55b is connected to an exhaust pipe (not shown). The first solenoid valve 54 has a first solenoid SV1. The second solenoid valve 55 has a second solenoid SV2.

FIG. 2 shows the structure of the electropneumatic proportional valve 56. This electro-pneumatic proportional valve 56 is a proportional valve 61 as an air supply solenoid valve.
And a proportional valve 62 as an exhaust electromagnetic valve. An input port 61a of the proportional valve 61 for air supply is connected to a compressed air supply source. Output port 6 of proportional valve 62 for exhaust
2a is connected to an exhaust pipe. Output port 61b of proportional valve 61 for air supply and input port 6 of proportional valve 62 for exhaust
2b is a first port 54a of the first solenoid valve 54, respectively.
Connected to.

As shown in FIG. 1, the controller 51 includes an interface circuit 71, a sequence control circuit 72, a vacuum pressure control circuit 73, and a central processing unit (not shown). The interface circuit 71 receives a signal for remote control and a signal for manual operation, respectively. The interface circuit 71 is electrically connected to the sequence circuit 72. The sequence circuit 72 includes the first solenoid valve 54
Solenoid SV1 of the second solenoid valve 55
2 is electrically connected. The interface circuit 71 is electrically connected to the vacuum pressure control circuit 73. The pressure sensor 25 is electrically connected to the control circuit 73.

In the air pressure control section 52, the electropneumatic proportional valve 5
6, a pulse drive circuit 58 is electrically connected. The drive circuit 58 is electrically connected to a position control circuit 57. The position control circuit 57 includes an amplifier 63
The potentiometer 37 is electrically connected via the.
A vacuum pressure control circuit 73 is electrically connected to the position control circuit 57.

The contents of the control executed by the controller 51 will be described below. As shown in FIG.
0 is fully opened, the controller 51 turns off the solenoid SV1 of the first solenoid valve 54 and the second solenoid valve 55
Is turned on. Thereby, the first port 55a of the second solenoid valve 55 communicates with the third port 55c. The second port 54b of the first solenoid valve 54 communicates with the third port 54c. As a result, the pressurized chamber 33b of the vacuum control valve 10 communicates with the compressed air supply source via the solenoid valves 54 and 55, and the compressed air is supplied to the pressurized chamber 33b. As a result, as shown in FIG. 6, the piston 34 and the valve body 40 move upward against the urging force of the return spring 35, and the stainless steel valve body 44 is farthest from the valve seat 45. That is, the vacuum control valve 10 is fully opened. In this state, the gas, particularly the process gas, supplied into the chamber 4A is sucked by the vacuum pump 9, so that the gas is quickly discharged from the chamber 4A and purged.

In order to bring the vacuum control valve 10 to an arbitrary target opening degree smaller than the full open state or to the fully closed state from the fully open state, the controller 51 sets the two solenoid valves 54 and 55 and the electropneumatic proportional valve 56 as follows. Control. Controller 51
Executes the first control and the second control that are continuous with each other.

That is, as shown in FIG. 10, first in the first control, the controller 51 controls the solenoid valves 54 and 55
Of the solenoids SV1 and SV2 are turned off. As a result, the second port 55b of the second solenoid valve 55 is connected to the third port 55b.
Port 55c. The second port 54b of the first solenoid valve 54 communicates with the third port 54c. As a result, the pressurizing chamber 10b of the vacuum control valve 10 is
It communicates with the exhaust pipe through 55. As a result, the piston 3
4 and the valve body 40 start to move downward based on the urging force of the return spring 35.

In the subsequent second control, as shown in FIG. 11, the controller 51 turns on the solenoid SV1 of the first solenoid valve 54. As a result, the third port 55c of the second solenoid valve 55 is closed, and the first port 54a of the first solenoid valve 54 communicates with the third port 54c. At the same time, the controller 51 controls the electropneumatic proportional valve 56. That is, the controller 51 communicates the pressurizing chamber 33b of the vacuum control valve 10 with the exhaust pipe via the first solenoid valve 54 and the electropneumatic proportional valve 56, and adjusts the vacuum pressure in the chamber 4A to a predetermined target value. The two proportional valves 61 and 62 of the electropneumatic proportional valve 56 are controlled so that At this time, the controller 51 monitors the detection value of the pressure sensor 25 and controls the electropneumatic proportional valve 56 so that the detection value matches the target value.
As a result, the piston 34 and the valve body 40 are
Moves further downward based on the urging force of the vacuum control valve 10.
Is adjusted to the target opening degree or the fully closed state. Thus, the supply of the vacuum pressure to the chamber 4A is further shut off, the suction of the process gas from the chamber 4A to the vacuum pump 9 is suppressed, and the pressure in the chamber 4A quickly reaches the target value.

Here, the controller 51 switches from the first control to the second control based on the measured value of the potentiometer 37, that is, the opening of the vacuum control valve 10. Specifically, when the value measured by the potentiometer 37 changes from a value corresponding to full opening of the vacuum control valve 10 to a predetermined value corresponding to a reference opening Rop smaller than full opening, the controller 51 switches from the first control to the second control. Switch to control.

Here, the contents of the second control performed by the controller 51 will be described in detail. In this embodiment, the stainless steel valve body 44 of the vacuum control valve 10 has a tapered surface 44a on its outer periphery. For this reason, the pressure in the chamber 4A is finely adjusted by the vacuum control valve 10 as follows. That is, by adjusting the stop position of the valve body 40,
The area of the gap between the valve seat 45 and the tapered surface 44a, that is, the opening degree of the vacuum control valve 10 slightly changes. Therefore, the controller 51 controls the solenoid valves 54 and 55 and the electropneumatic proportional valve 56 as described below.

That is, when the inside of the chamber 4A is adjusted to a vacuum pressure of a low level, the controller 51 causes the two solenoid valves 54 and 54 to stop at a position where the straight surface 44b of the stainless steel valve body 44 faces the valve seat 45. 55 is controlled. When adjusting the inside of the chamber 4A to a moderate vacuum pressure, the controller 51 controls the two solenoid valves 5 so that the tapered surface 44a of the stainless steel valve body 44 stops at a position opposing the valve seat 45.
4, 55 are controlled. Further, when the inside of the chamber 4A is adjusted to a high vacuum pressure, the tapered surface 44a is
Controller 5 so that it stops at a position slightly away from
1 controls both solenoid valves 54 and 55.

More specifically, in the controller 51, the sequence control circuit 72 receives a target value for the pressure in the chamber 4A from the central processing unit via the interface circuit 71. Thereby, the solenoid SV1 of the first solenoid valve 54 is turned on, and the solenoid SV2 of the second solenoid valve 55 is turned off. Further, the vacuum pressure control circuit 73
Receives the target value related to the pressure via the interface circuit 71.

The vacuum pressure control circuit 73 compares the target value of the vacuum pressure received from the interface circuit 71 with the current value detected by the pressure sensor 25. The vacuum pressure control circuit 73 controls the electropneumatic proportional valve 56 via the pulse drive circuit 58 in order to adjust the opening of the vacuum control valve 10 so that the two values match.

That is, when the vacuum pressure in the chamber 4A is closer to the atmospheric pressure than the target value, the vacuum pressure control circuit 73 moves the position of the piston 34 of the vacuum control valve 10 upward to increase its opening. . When the vacuum pressure in the chamber 4A is closer to the absolute vacuum pressure than the target value, the vacuum pressure control circuit 73 controls the electropneumatic proportional valve 56 to reduce the opening of the vacuum control valve 10.

Here, the pulse drive circuit 58 converts the signal from the vacuum pressure control circuit 73 into a pulse signal, and supplies the pulse signal as an opening / closing signal to the proportional valves 61 and 62 for air supply and exhaust. Each of the proportional valves 61 and 62 opens and closes in response to a pulse signal to adjust the air pressure supplied to the pressurizing chamber 33b of the vacuum control valve 10. Here, the two proportional valves 61 and 62 are electromagnetic valves that separate a valve body from a valve seat according to an input voltage of a pulse signal.

The pulse drive circuit 58 supplies compressed air for driving to the pressurizing chamber 33b of the vacuum control valve 10 by turning on the proportional valve 61 for air supply. At the same time, by turning on the exhaust proportional valve 62, the pulse drive circuit 58 releases a part of the compressed air to the exhaust pipe, and adjusts the size of the compressed air to be supplied to the pressurizing chamber 33b of the vacuum control valve 10. adjust.

In this embodiment, the pulse drive circuit 58 includes a proportional valve 61 connected to a compressed air supply source and a proportional valve 62 connected to an exhaust pipe.
8, the compressed air supplied to the pressurizing chamber 33b is adjusted. Therefore, in the vacuum control valve 10, the piston 34 can be accurately stopped at a predetermined position with a high response speed, and the vacuum control valve 10 can be adjusted to a predetermined opening.

That is, proportional valves 61 and 6 for air supply and exhaust are provided.
2 are driven by pulse signals which change at the same constant interval as each other. The ratio between the on-time and off-time of the proportional valves 61 and 62, that is, the duty ratio is changed based on the pulse interval, so that each proportional valve 6 is changed.
The amount of air passing through 1,62 is varied.

Here, the duty ratio of the pulse signal supplied to the two proportional valves 61 and 62 is determined by the position control circuit 57 as follows. To make the opening of the vacuum control valve 10 larger than the target value, the duty ratio supplied to the proportional valve 61 for air supply is made larger. Thereby, the air flow rate supplied to the pressurizing chamber 33b of the vacuum control valve 10 increases,
The pressure in the pressurizing chamber 33b increases, and the valve body 40 moves in the opening direction. This movement is measured by the potentiometer 37, and the measured value is sent to the position control circuit 57. Since the measured value of the potentiometer 37 and the target value related to the opening of the vacuum control valve 10 are close to each other, the duty ratio supplied to the proportional valve 61 for air supply is reduced. When the two values completely match each other, the proportional valve 6
The duty ratio supplied to 1 becomes the bias value.

By changing the opening of the vacuum control valve 10 to a direction closer to its target value, the duty ratio supplied to the exhaust proportional valve 62 increases. As a result, the flow rate of air discharged from the pressurizing chamber 33b increases, and
The pressure of 3b decreases, and the valve body 40 moves in the closing direction. This movement is measured by the potentiometer 37, and the measured value is sent to the position control circuit 57. When the measured value of the potentiometer 37 and the target value related to the opening of the vacuum control valve 10 are close to each other, the duty ratio supplied to the exhaust proportional valve 62 is reduced. When the two values completely match, the duty ratio supplied to the proportional valve 62 becomes the bias value.

This bias value is provided for the operation of each of the proportional valves 61 and 62 in order to eliminate a dead zone for a pulse signal. The reason that each of the proportional valves 61 and 62 has a dead zone is that
This is due to the surface pressure load of the compressed air acting on the valves 61 and 62 and the urging force of the return springs provided on the valves 61 and 62.

For example, when the vacuum pressure in the chamber 4A is closer to the atmospheric pressure than the target value, the valve body 40 of the vacuum control valve 10 is slightly moved upward to increase its opening. As a result, the amount of the process gas sucked from the chamber 4A by the vacuum pump 9 increases, and the value of the vacuum pressure in the chamber 4A can be made to match its target value.

That is, the vacuum pressure control circuit 73 supplies a pulse signal to the air supply proportional valve 61 via the position control circuit 57 and the pulse drive circuit 58. As a result, the valve element of the proportional valve 61 is separated from the valve seat, and a large amount of compressed air for driving is supplied to the vacuum control valve 10. Then, the piston 34 and the valve body 40 move upward, and the opening of the vacuum control valve 10 increases.

Here, the piston 34 cannot be stopped at a predetermined position simply by driving the proportional valve 61 for air supply. This is because the piston 34 may move too much. In the present embodiment, when the piston 41 moves excessively, the compressed air supplied to the vacuum control valve 10 is reduced by the proportional valve 62 for exhaust. As a result, the piston 3
4 can be quickly and accurately stopped at a predetermined position. That is, the opening of the vacuum control valve 10 can be accurately adjusted to its target value.

On the other hand, for example, when the vacuum pressure in the chamber 4A is closer to the absolute vacuum than the target value, the valve body 40 is moved slightly downward. Thus, the opening degree of the vacuum control valve 10 is reduced, and the amount of the process gas in the chamber 4A sucked by the vacuum pump 19 is reduced. Thereby, the vacuum pressure in the vacuum chamber 11 can be made to coincide with the target value.

That is, the vacuum pressure control circuit 73 supplies a pulse signal to the exhaust proportional valve 62 via the position control circuit 57 and the pulse drive circuit 58. As a result, the valve element of the proportional valve 62 is separated from the valve seat, and the supply of air to the pressurizing chamber 33b of the vacuum control valve 10 is stopped.
Increase exhaust from b. As a result, the piston 34 and the valve body 40 of the vacuum control valve 10 move downward, and the vacuum control valve 1
The opening degree of 0 becomes small.

Here, it is difficult to accurately stop the piston 34 of the vacuum control valve 10 at a predetermined position only by driving the proportional valve 62 for exhaust. This is because the piston 34 may move too much. In the present embodiment,
When the piston 34 moves excessively, the compressed air supplied to the vacuum control valve 10 is increased by the proportional valve 61 for air supply, so that the piston 34 can be quickly and accurately stopped at a predetermined position. . Thereby, the vacuum control valve 1
The opening of 0 can be quickly and accurately adjusted to its target value.

As described above, in this embodiment, in the vacuum pressure control system corresponding to each of the chambers 4A to 4E, when the vacuum pump 9 operates, the process gas in the chambers 4A to 4E is sucked. The inside of the chambers 4A to 4E is evacuated. Here, the vacuum control valve 10
Is changed, the amount of process gas sucked from the chambers 4A to 4E to the vacuum pump 9 is adjusted, and the vacuum pressure in the chambers 4A to 4E is changed. This vacuum pressure is detected by the pressure sensor 25 and sent to the controller 51.

The controller 51 includes the chambers 4A to 4E
The opening degree of the vacuum control valve 10 is adjusted by controlling the air pressure control unit 52 based on the detected vacuum pressure so that the vacuum pressure in the inside becomes a predetermined target value. Here, the opening degree of the vacuum control valve 10 is determined by setting the valve body 40 to the pilot valve 3.
1 to change the size of the gap between the valve seat 45 and the tapered surface 44a of the valve body 40 (stainless valve body 44). In order to move the valve element 40, compressed air (pressure) adjusted by the first and second solenoid valves 54 and 55 and the electropneumatic proportional valve 56 is supplied to the pressurizing chamber 33b of the pilot valve 31. . Controller 51
Controls the compressed air supplied to the pressurizing chamber 33b of the pilot valve 31 by controlling the solenoid valves 54 and 55 and the electropneumatic proportional valve 56. Thereby, the vacuum control valve 10
Of the valve body 40 is moved, and the opening degree of the valve body 40 is changed.
The vacuum pressure in A-4E is adjusted to its target value.

In this embodiment, the two solenoid valves 54 and 55 used to adjust the opening of the vacuum control valve 10 are
The pilot valve 31 operates as a rapid exhaust valve for quickly releasing the compressed air supplied to the pressurizing chamber 33b from the pilot chamber 31b. For this purpose, the controller 51 controls both the solenoid valves 54 and 55.

Therefore, it is assumed here that compressed air is supplied to the pressurizing chamber 33b of the pilot valve 31 and the vacuum control valve 10 is opened to some extent. At this time, the chambers 4A to 4E
It is assumed that the controller 51 controls both the solenoid valves 54 and 55 in order to adjust the inside of the device from a high vacuum pressure to a low vacuum pressure. As a result, the compressed air is quickly released from the pressurizing chamber 33b, the valve body 40 of the vacuum control valve 10 moves quickly, and the opening thereof is rapidly reduced. As a result, the amount of process gas sucked from the chambers 4A to 4E to the vacuum pump 9 decreases quickly, and the vacuum pressure in the chambers 4A to 4E decreases quickly. For this reason, chamber 4
The time required for adjusting the inside of A to 4E from a high vacuum pressure to a low vacuum pressure can be shortened.

In particular, in this embodiment, the vacuum control valve 1
In order to bring the vacuum pressure in the chambers 4A to 4E closer to a predetermined target value by changing 0 from a fully open state to an arbitrary opening degree smaller than that or a fully closed state, the controller 51 performs the first and second operations. Is continuously executed.

For example, as shown in FIG. 12, when the vacuum control valve 10 is fully open, the controller 51 executes the first control. That is, at time t1, the controller 51 switches the second solenoid valve 55 from on to off while the first solenoid valve 54 is off. As a result, both solenoid valves 54 and 55 are operated as quick exhaust valves. After that, the controller 51 executes the second control. That is,
At time t2, when the opening measured by the potentiometer 37 reaches the predetermined reference value Rop, the controller 51 turns on the first solenoid valve 54 while keeping the second solenoid valve 55 off. At the same time, the controller 51 turns on the electropneumatic proportional valve 56 and controls the two proportional valves 61 and 62 of the valve 56. Here, the predetermined reference value Rop means an optimum valve opening for making the vacuum pressure reach the target pressure Tvp in the shortest time. That is, the vacuum pressure is reduced to the target pressure Tv.
The valve opening degree for setting to p is determined in advance by the CPU of the controller 51.
And it is set as a reference value Rop. Then, in the actual operation, when the valve opening reaches the reference value Rop, the control is quickly switched to the control of the vacuum proportional valve 56. FIG.
Is input to the controller 51 in advance and stored, or the C value of the controller 51 is
This is set depending on whether the PU makes a judgment.

Therefore, in the first control, the compressed air is quickly released from the pressurizing chamber 33b of the pilot valve 31, and the opening degree of the vacuum control valve 10 is rapidly increased as shown from time t1 to t2 in FIG. To decrease. Thereby, the chamber 4
The flow of the suction air from A to 4E to the vacuum pump 9 is quickly shut off, and the vacuum pump 9 is removed from the chambers 4A to 4E.
The amount of process gas sucked into the chamber quickly decreases, and the vacuum pressure in the chambers 4A to 4E rapidly decreases. Thereafter, in the second control, when the measured value of the potentiometer 37 reaches a predetermined reference opening Rop, the electropneumatic proportional valve 5
6 is controlled. Thereby, the compressed air supplied to the pressurizing chamber 33b of the pilot valve 31 is finely adjusted, and the opening of the vacuum control valve 10 is finely adjusted. Thereby, the vacuum pressure in the chambers 4A to 4E is further adjusted, and FIG.
2, at time t3, the predetermined target pressure Tv
converges to p. As a result, the responsiveness of the vacuum control valve 10 can be improved, and the time required for adjusting the vacuum pressure can be reduced.

From this, the plurality of chambers 4A to 4E
In the single-wafer apparatus 1 configured to sequentially process one wafer 2 in each of the chambers 4A to 4E
Can reduce the tact time required for a series of steps in the process, and can improve the process capability of the apparatus 1.

According to this embodiment, the pilot valve 3
In 1, the piston 34 is fixed to the cylinder interior wall of the cylinder 33 via the bellow ram 38. For this reason,
The movement resistance generated between the piston 34 and the inner wall of the cylinder is reduced. Therefore, the movement and the stop of the piston 34 with respect to the cylinder chamber inner wall are respectively facilitated, and the position adjustment is smoothly performed. Therefore, stick-slip occurring between the cylinder chamber inner wall and the piston 34 is reduced. In addition, the piston 34 can be moved with high responsiveness and accurate positional accuracy. In this sense, the opening degree of the vacuum control valve 10 can be adjusted with high responsiveness and high accuracy. Eventually, chamber 4A ~
The vacuum pressure in 4E can be adjusted with high responsiveness and high accuracy to the target pressure Tvp.

In this sense, inside the chambers 4A to 4E,
It is possible to accurately adjust over a wide range from a low vacuum pressure close to the atmospheric pressure to a high vacuum pressure. Particularly, in the range of low vacuum pressure, the chambers 4A to 4E
It is possible to finely adjust the vacuum pressure in the inside.

In this embodiment, in one vacuum control system, only one vacuum control valve 10 is provided to adjust the vacuum pressure in one of the chambers 4A to 4E. Therefore, unlike the conventional system, it is not necessary to separately provide a bypass valve or the like for adjusting the vacuum pressure. In this sense, it is possible to make the entire vacuum control system compact and to reduce manufacturing costs.

In this embodiment, the first and second solenoid valves 54 and 55 constituting the quick exhaust valve are controlled by the controller 5.
It operates in response to a switching signal from the control unit 1. This allows
The flow of the pilot valve 31 to the electropneumatic proportional valve 56, the supply source of the compressed air or the exhaust pipe is switched, and the supply and discharge of the compressed air to the pressurizing chamber 33b of the pilot valve 31 are adjusted. In particular, in this embodiment, the solenoid valves 54 and 55 are provided without providing a special quick exhaust valve in the system.
Is also used as a quick exhaust valve. That is, both solenoid valves 54,
55 is used not only for discharging compressed air from the pressurizing chamber 33b but also for supplying compressed air to the pressurizing chamber 33b. Also in this sense, the number of parts and members for configuring the present system can be reduced, and the system can be made more compact.

In this embodiment, a proportional valve 61 for air supply and a proportional valve 62 for exhaust constituting the electropneumatic proportional valve 56 each receive a pulse signal from the controller 51 and receive a time interval corresponding to the pulse frequency. Open / close operation with.
Thereby, the compressed air supplied to the pressurizing chamber 33b of the pilot valve 31 and the compressed air released from the pressurizing chamber 33b to the exhaust pipe are adjusted.

Therefore, the two proportional valves 61 and 62 can be used simultaneously in parallel, and the compressed air for the pressurizing chamber 33b can be finely adjusted. As a result, the degree of opening of the vacuum control valve 10 and thus the vacuum pressure in the chambers 4A to 4E can be finely adjusted. In this sense, the adjustment of the vacuum pressure by the first and second controls can be further smoothly performed.

The present invention is not limited to the above embodiment, but can be implemented as follows without departing from the spirit of the invention.

(1) Although the potentiometer 37 is used as the opening sensor in the above embodiment, a magnetic linear scale, an optical linear scale, or a rotary encoder can be used as the opening sensor.

(2) In the above embodiment, the controller 51 controls the vacuum pressure by applying the detection value of the pressure sensor 25 to the control of the electropneumatic proportional valve 56. On the other hand, the feedforward control relating to the vacuum pressure may be performed by reflecting the differential element in the detection value of the pressure sensor 25. According to this control,
The vacuum pressure in the chambers 4A to 4E can be adjusted to the target value without overshooting.

(3) In the above embodiment, the electropneumatic proportional valve 5
A combination of an electromagnetic valve for supplying air and a solenoid valve for exhausting (EV valve) is used as 6, but the same applies when a proportional valve of a nozzle flapper type is used.

[0095]

According to the first aspect of the present invention,
By adjusting the opening of one vacuum control valve, the vacuum pressure in the vacuum vessel is adjusted. In order to adjust the opening of the vacuum control valve, the gas pressure supplied to the pilot valve is adjusted by controlling the servo valve. Further, by controlling the quick exhaust valve, the gas pressure is quickly released from the pilot valve. Therefore, when the gas pressure is supplied to the pilot valve and the vacuum control valve is open, by controlling the quick exhaust valve, the gas pressure is quickly released from the pilot valve, and the opening degree of the vacuum control valve is rapidly increased. Decrease to
The vacuum pressure in the vacuum vessel decreases quickly. For this reason,
The time required for adjusting the inside of the vacuum vessel from a high vacuum pressure to a low vacuum pressure can be shortened, and the whole system can be made compact.

According to the second aspect of the present invention, unlike the configuration of the first aspect, in order to quickly bring the vacuum pressure in the vacuum vessel close to a predetermined value by changing the opening of the vacuum control valve. First, the quick exhaust valve is operated to quickly release the gas pressure from the pilot valve, and then, after the opening of the vacuum control valve reaches a predetermined value, the servo valve is controlled to adjust the vacuum pressure. I have. For this reason, when adjusting the inside of a vacuum container from a high vacuum pressure to a low vacuum pressure, the time required for the adjustment can be shortened, and further, the whole system can be made compact. At the same time, the vacuum pressure can be adjusted to a target value with high accuracy.

According to the third aspect of the present invention, in the configuration of the first or second aspect, the piston moving in the hollow cylinder chamber, the inner peripheral end is fixed to the piston, and the outer peripheral end is fixed to the piston. The pilot valve includes a bellows part fixed to the inner wall of the cylinder chamber. Therefore, in addition to the functions and effects of the first or second invention, the movement / stop and position adjustment of the piston with respect to the inner wall of the cylinder of the pilot valve are facilitated. As a result, the effect that the vacuum pressure in the vacuum vessel can be accurately adjusted to the target value is exhibited.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the first electromagnetic switch for switching the communication of the pilot valve with the servo valve or the second electromagnetic valve. Activating the quick exhaust valve by supplying a switching signal to at least one of the valve and a second electromagnetic valve that switches communication of the first electromagnetic valve to a gas pressure supply source or an exhaust pipe that releases the gas pressure. Like that. Therefore, in addition to the function and effect of any one of the first to third aspects, the passage of the pilot valve to the servo valve, the supply source or the exhaust pipe is switched, and the supply and discharge of the gas pressure to the pilot valve are adjusted. You. Thus, an effect that an electromagnetic valve capable of supplying gas pressure to the pilot valve can be used also as a rapid exhaust valve can be achieved.

The fifth invention according to claim 5 is the first invention.
In any one of the fourth to fourth aspects of the invention, the air supply solenoid valve connected between the pilot valve and the gas pressure supply source and the pilot valve and an exhaust pipe for releasing the gas pressure are connected. And a solenoid valve for exhaust connected to the solenoid valve are configured as components of the servo valve, and a pulse signal is supplied to these solenoid valves. Therefore, in addition to the operation and effect of any one of the first to fourth inventions, the supply of gas pressure to the pilot valve and the discharge of gas pressure from the pilot valve are adjusted by the respective solenoid valves. Thereby, the gas pressure supplied to the pilot valve can be finely adjusted, and an effect that the vacuum pressure can be finely adjusted by the vacuum control valve is exhibited.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control configuration of a vacuum pressure control system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an electropneumatic proportional valve.

FIG. 3 is a schematic configuration diagram illustrating a configuration of a single-wafer apparatus for manufacturing a semiconductor.

FIG. 4 is a schematic configuration diagram showing a vacuum pressure control system provided corresponding to one chamber of the single-wafer apparatus.

FIG. 5 is a cross-sectional view showing the vacuum control valve when closed.

FIG. 6 is a sectional view showing the vacuum control valve when opened.

FIG. 7 is a sectional view showing the operation of the poppet valve.

FIG. 8 is a sectional view showing the operation of the poppet valve.

FIG. 9 is a block diagram showing the operation of the first and second solenoid valves and the electropneumatic proportional valve.

FIG. 10 is a block diagram showing the operation of first and second solenoid valves and an electropneumatic proportional valve.

FIG. 11 is a block diagram showing the operation of the first and second solenoid valves and the electropneumatic proportional valve.

FIG. 12 is a time chart showing behaviors of first and second solenoid valves, an electropneumatic proportional valve, a vacuum control valve, and a vacuum pressure.

FIG. 13 is a schematic configuration diagram showing a conventional vacuum pressure control system.

[Explanation of symbols]

 4A to 4E Vacuum chamber 7, 8 Piping 9 Vacuum pump 10 Vacuum control valve 25 Pressure sensor 31 Pilot valve 33 Pneumatic cylinder 33a Atmospheric chamber 33b Pressurizing chamber 31 Piston 38 Bellofram 40 Valve body 44 Stainless steel valve body 44a Tapered surface 45 Valve seat 51 Controller 54 First solenoid valve 55 Second solenoid valve 56 Electropneumatic proportional valve 61 Proportional valve for air supply 62 Proportional valve for exhaust

Claims (5)

[Claims] A vacuum vessel, a vacuum pump for sucking a gas supplied into the vacuum vessel, a pipe for connecting the vacuum vessel and the vacuum pump, and a pipe provided on the pipe. A vacuum control valve configured to change the vacuum pressure in the vacuum vessel by changing its own opening degree, a pressure sensor for detecting the vacuum pressure in the vacuum vessel, and a vacuum pressure in the vacuum vessel. A control device for controlling the opening degree of the vacuum control valve based on the detected vacuum pressure so that a predetermined value is obtained. And a pilot valve,
The valve body includes a tapered surface that is tapered on its outer periphery, and the size of the gap between the valve seat and the tapered surface is reduced by the valve body moving along the central axis of the hole of the valve seat. The opening degree of the vacuum control valve changes, and the pilot valve is supplied with a gas pressure adjusted by a servo valve to move the valve body. Adjusting the gas pressure supplied to the pilot valve by controlling the servo valve to adjust the vacuum pressure to the predetermined value by changing the opening of the control valve; A quick exhaust valve that operates to quickly release the gas pressure from the valve, and the control device quickly releases the gas pressure from the pilot valve to quickly open the vacuum control valve. To make small of the vacuum pressure control system is characterized in that a controlling of the quick exhaust valve. 2. A vacuum vessel, a vacuum pump for sucking a gas supplied into the vacuum vessel, a pipe for connecting the vacuum vessel and the vacuum pump, and a pipe provided on the pipe. A vacuum control valve configured to change the vacuum pressure in the vacuum vessel by changing its own opening degree, a pressure sensor for detecting the vacuum pressure in the vacuum vessel, and a vacuum pressure in the vacuum vessel. A control device for controlling the opening degree of the vacuum control valve based on the detected vacuum pressure so that a predetermined value is obtained. And a pilot valve,
The valve body includes a tapered surface that is tapered on its outer periphery, and the size of the gap between the valve seat and the tapered surface is reduced by the valve body moving along the central axis of the hole of the valve seat. The opening degree of the vacuum control valve is changed, and the pilot valve is supplied with a gas pressure adjusted by a servo valve to move the valve element, and supplied to the pilot valve. A quick exhaust valve that operates to quickly release gas pressure from the valve; an opening sensor for detecting an opening of the vacuum control valve; and the control device changes an opening of the vacuum control valve. The first control and the second control are continuously performed in order to quickly bring the vacuum pressure closer to the predetermined value, and the first control is based on the gas pressure supplied to the pilot valve. Quickly escaped from the valve Operating the quick exhaust valve in order to adjust the vacuum pressure to the predetermined value when the detected opening degree reaches a predetermined value. Controlling a valve. 3. The system according to claim 1, wherein the pilot valve has a hollow cylinder chamber, a piston moving in the cylinder chamber, and an inner peripheral end fixed to the piston. A vacuum pressure control system, wherein an outer peripheral end portion includes a bellofram fixed to an inner wall of the cylinder chamber. 4. The system according to claim 1, wherein the quick exhaust valve has a first solenoid valve and a second solenoid valve that selectively open and close when energized. The first solenoid valve switches the communication of the pilot valve to the servo valve or the second solenoid valve, and the second solenoid valve is connected to a supply source of the gas pressure or an exhaust pipe for releasing the gas pressure. Switching communication of the first solenoid valve; and the control device operates the quick exhaust valve,
Supplying a switching signal to at least one of the first solenoid valve and the second solenoid valve. 5. The system according to claim 1, wherein the servo valve opens and closes at a time interval according to a pulse frequency, and supplies the gas for the gas pressure. Having a solenoid valve for air supply connected between a source and the pilot valve, and a solenoid valve for exhaust gas connected between the exhaust pipe and the pilot valve for releasing the gas pressure; Wherein the control device controls an opening degree of the vacuum control valve by supplying a pulse signal to the air supply solenoid valve and the exhaust solenoid valve. Vacuum pressure control system.