JP4006101B2 - Vacuum pump control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a vacuum pump that controls regeneration processing and the like of a plurality of vacuum pumps such as cryopumps.
[0002]
[Prior art]
In general, a cryopump condenses water and the like by a first-stage cryopanel cooled to 60K to 80K, freezes and collects it, and a second-stage cryopanel cooled to 10K to 20K uses a nitrogen gas or an argon gas. Condensate etc. to freeze and collect. Further, hydrogen gas or the like that does not condense at 10K to 20K is adsorbed by activated carbon attached to the second-stage cryopanel. Such a cryopump is attached to a vacuum chamber in a semiconductor manufacturing apparatus such as a sputtering apparatus, and places the inside of the vacuum chamber in a high vacuum state.
[0003]
The semiconductor manufacturing apparatus is usually provided with a plurality of vacuum chambers, each of which has the cryopump. As described above, there is a cryopump control apparatus for controlling the regeneration processing operation of a plurality of cryopumps installed in a semiconductor manufacturing apparatus as shown in FIG. 3 (Japanese Patent Publication No. 4-501751).
[0004]
Water vapor and process gas generated in the vacuum chambers 2, 3, and 4 of the semiconductor manufacturing apparatus 1 are frozen and collected by the corresponding cryopumps 5, 6, and 7, and the respective cryopumps 5, 6, and 7 are collected. It is stored in the first and second stage cryopanels and activated carbon (both not shown). Thus, the vacuum chambers 2, 3, and 4 are kept in a vacuum state. As described above, since the cryopumps 5, 6, and 7 are reservoir-type pumps, regeneration processing for periodically discharging the accumulated gas to the outside of the pump is necessary. Such reproduction processing is performed based on control by the control devices 8, 9, and 10.
[0005]
One controller 8, 9, 10 is installed in each cryopump 5, 6, 7. During the regeneration process, the control devices 8, 9, 10 control the temperature sensors, vacuum gauges, heaters (not shown), etc. provided in the cryopumps 5, 6, 7, respectively. Heat is added to the stored gas and the gas is exhausted. After that, the compressor unit 11 is driven to lower the cryopumps 5, 6, 7 to a temperature at which evacuation is possible. In FIG. 3, refrigerant supply piping from the compressor unit 11 to the cryopumps 5, 6, and 7 is omitted.
[0006]
The control devices 8, 9, 10 include the cryopumps 5, 6, 7 including the control of the gate valves 12, 13, 14 and the roughing pump (not shown) in addition to the regeneration processing control as described above. The evacuation control, the monitoring of the panel temperature and the degree of vacuum, and the like are performed according to the contents of communication with the host computer 15 on the semiconductor manufacturing apparatus 1 side. The main control device 10 and the host computer 15 are connected by a communication line 16 so that each control device 8, 9, 10 can execute each control without any delay. 9 and 10 are also connected by communication lines 17 and 18, respectively. In this way, the mutual control state can be monitored.
[0007]
Further, in order to control the compressor unit 11 from each of the control devices 8, 9, 10 and to supply power to the control devices 8, 9, 10 from the compressor unit 11, each control device 8, 9, 10 and the compressor unit 11 are connected by a cable. Further, in order to perform the regeneration process control and the vacuum exhaust process control, the heaters, temperature sensors, motorized valves, vacuum gauges, etc. of the cryopumps 5, 6, 7 and the control devices 8, 9, 10 are connected by cables. It is connected.
[0008]
[Problems to be solved by the invention]
However, the conventional cryopump control device that controls the regeneration processing of the plurality of cryopumps has the following problems. That is, a plurality of control devices 8, 9, 10 and a host computer 15 are provided in one evacuation system (in other words, a plurality of CPUs (central processing units) are provided), and the operation states of each other are controlled. Since monitoring is performed, there is a problem in that the entire control program becomes complicated. In addition, there is a problem that reliability is lowered due to disconnection of the communication lines 17 and 18 between the control devices 8, 9 and 10, noise from the surroundings, and the like. For this reason, it is necessary to take a connection structure in which the communication lines 17 and 18 are not disconnected, and to take measures against noise from the surroundings, resulting in a complicated structure and an increase in cost.
[0009]
Further, as described above, one controller 8, 9, 10 is installed for each cryopump 5, 6, 7, and the controller 8, 9, 10 and the cryopump 5, 6, 7 Is integrated. Therefore, there is a problem that the cryopumps 5, 6, and 7 themselves are increased in size and press the space of the semiconductor manufacturing apparatus 1 to be connected. Further, since the control devices 8, 9, and 10 are directly provided in the cryopumps 5, 6, and 7, the reactive gas leaked from the cryopumps 5, 6, and 7 enters the control devices 8, 9, and 10, respectively. There is also a problem that a malfunction occurs in the internal electrical components.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum pump control device that can control a plurality of vacuum pumps with a simple structure and high reliability.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a control device for a vacuum pump of the invention according to claim 1 comprises:
A plurality of vacuum pumps such as a cryopump or a cold trap that evacuates the vacuum chamber by freezing and collecting the gas in the vacuum chamber on a panel cooled to a cryogenic temperature;
Provided to a compressor unit compressor body for supplying a compressed refrigerant to the respective vacuum pump is mounted, with only one control unit for controlling the operation of the vacuum pump and the compressor body of said respective <br /> with a,
The controller may, and operating including a vacuum exhaust treatment operation and the reproduction processing operation of the respective vacuum pumps, the operation and including a start and stop operation and protection operation of the compressor body, so as to centralized control <br/> It is characterized by that.
[0012]
According to the above configuration, the only control unit that controls the operation of the plurality of vacuum pumps is provided in the compressor unit, and also controls the operation including the start / stop operation and the protection operation of the compressor body. . Thus, by controlling the operations of the plurality of vacuum pumps and the compressor by one control unit, the control program for each of the vacuum pumps and the compressor main body is simplified. Furthermore, a communication line for monitoring the states of the vacuum pumps is not necessary, and malfunctions due to noise are reduced. Furthermore, an increase in the size of each vacuum pump is prevented.
[0013]
According to a second aspect of the present invention, in the vacuum pump control apparatus according to the first aspect of the present invention, a sensor provided in each of the vacuum pumps and a detection signal from each of the sensors is transmitted to the control unit. It is characterized by having an amplifier interposed in the cable.
[0014]
According to the above configuration, since the control unit for controlling the operations of the plurality of vacuum pumps is provided in the compressor unit, the distance between each vacuum pump and the control unit is increased. Even in such a case, since the minute output from the sensor of each vacuum pump is amplified by the amplifier provided in the cable, the minute output from each sensor is attenuated by transmission or the SN ratio is deteriorated. Is prevented.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a configuration diagram illustrating an example of a control device for a vacuum pump according to the present embodiment. As in the case of the cryopump control device shown in FIG. 3, the vacuum pump control device in the present embodiment has a plurality of cryopumps connected to the vacuum chambers 22, 23, 24 provided in the semiconductor manufacturing apparatus 21. The pumps 25, 26, and 27 are controlled for evacuation processing and regeneration processing.
[0016]
The control device for the vacuum pump in the present embodiment is provided integrally with the compressor unit 28. That is, the compressor unit 28 includes a compressor unit 29 and a control unit 30. The compressor unit 29 includes a compressor body 31, a solenoid valve, an adsorber, a relay, a timer, a pressure / temperature sensor, and the like, compresses helium gas as a refrigerant, and supplies the compressed helium gas to the cryopumps 25, 26, and 27. . The control unit 30 controls the operations of the compressor unit 29 and the cryopumps 25, 26, and 27 as described in detail below. In FIG. 1, refrigerant supply piping from the compressor unit 29 to the cryopumps 25, 26, 27 is omitted.
[0017]
The control unit 30 is generally configured by I / O ports 32 and 34, a cryopump drive unit 33, a compressor drive unit 35, a CPU 36, and a communication port 37. The cryopump drive unit 33 includes a memory, a relay, a timer, and the like that are used during cryopump control. The compressor driving unit 35 is configured by a memory, a relay, a timer, and the like that are used during compressor control. The CPU 36 collects data from the temperature sensors and vacuum gauges (both not shown) of the cryopumps 25, 26, and 27 via the I / O port 32, and the cryopump drive unit is based on these data. 33 is used to set the evacuation processing procedure and the regeneration processing procedure for each cryopump 25, 26, 27. Then, according to the set procedure, control signals are sent to the cryopumps 25, 26, 27, the gate valves 38, 39, 40, the heaters and the motorized valves (both not shown) via the I / O port 32. Thus, the evacuation processing operation and the regeneration processing operation of each cryopump 25, 26, 27 are controlled.
[0018]
The CPU 36 sends a control signal to the compressor unit 29 via the I / O port 34 in accordance with the set evacuation processing procedure and regeneration processing procedure. In this way, the start / stop operation and the protection operation of the compressor body 31 constituting the compressor unit 29 are controlled. That is, in the present embodiment, the control of the compressor body 31 and the control of the cryopumps 25, 26, 27 are performed by one CPU 36 of the control unit 30 provided in the compressor unit 28.
[0019]
The CPU 36 is connected to a host computer 41 of the semiconductor manufacturing apparatus 21 via a communication port 37 through a communication line 48, and transmits and receives control commands and status reports for the entire cryopump system.
[0020]
As described above, in the present embodiment, the control unit 30 that controls the vacuum exhaust processing and the regeneration processing of the plurality of cryopumps 25, 26, 27 is integrated with the compressor unit 29 on which the compressor body 31 is mounted. The compressor unit 28 is provided. Therefore, one CPU 36 of the control unit 30 can centrally control the operation of each cryopump 25, 26, 27 and the operation of the compressor body 31, and the vacuum pumping process of each cryopump 25, 26, 27 can be performed. The control program for the reproduction process and the control program for the compressor body 31 can be simplified. Further, since the program is simplified, finer control can be achieved.
[0021]
Further, in order to centrally control the operation of the cryopumps 25, 26, 27 and the operation of the compressor with one CPU 36, there is a communication line for monitoring the states of the cryopumps 25, 26, 27 with each other. It becomes unnecessary. Therefore, the cost can be reduced combined with the use of one CPU or the like, and high reliability can be obtained by reducing malfunction caused by noise. For this reason, the cost for noise countermeasures can be reduced.
[0022]
Furthermore, it is not necessary to mount a control device on each of the cryopumps 25, 26, and 27, and an increase in size of the cryopumps 25, 26, and 27 can be prevented. Therefore, the space of the semiconductor manufacturing apparatus 21 to which each cryopump 25, 26, 27 is connected is not compressed.
[0023]
In the above configuration, the distance between the cryopumps 25, 26, 27 and the control means of the cryopumps 25, 26, 27 is longer than in the conventional cryopump control device shown in FIG. Therefore, as a temperature sensor attached to each cryopump 25, 26, 27, when an extremely small gold-iron chromel temperature sensor having an output of −5309 μV to +599 μV when the temperature is 0 K to 300 K is used, The detected temperature is far from the actual temperature due to signal attenuation and noise caused by transmission. Therefore, in the present embodiment, the amplifier circuits 45, 46, 47 are provided in the cables 42, 43, 44 that connect the I / O port 32 of the compressor unit 28 and the cryopumps 25, 26, 27. is there. Thus, for example, the detection error can be greatly reduced by amplifying the detection signal of the temperature sensor by about 100 times.
[0024]
As a vacuum pump for condensing the gas in the vacuum chamber into a cryogenic panel for freezing and collecting, there is a cold trap for exhausting water vapor as shown in FIG. 2 in addition to the cryopump described above. The cold trap 51 includes a refrigerator 52, a cylindrical enclosure 53 attached to the tip of the refrigerator 52, and a cylindrical panel 55 attached to the heat station 54 of the refrigerator 52 and housed in the enclosure 53. It is roughly composed of. A vacuum chamber to be evacuated is attached to a flange provided at the upper end of the enclosure 53.
[0025]
In the above configuration, the panel 55 is cooled to a temperature of 120K to 150K by the refrigerator 52, the water vapor in the vacuum chamber is frozen and collected, and the water vapor in the vacuum chamber is exhausted. Then, when water vapor is frozen and collected on the entire surface of the panel 55 and the degree of vacuum is lowered, the panel 55 is heated by the heater 56 and the like, and the frozen water molecules are vaporized and regenerated.
[0026]
Similar to the cryopumps 25, 26 and 27, the cold trap 51 as described above is installed and used in each of a plurality of vacuum chambers provided in a semiconductor manufacturing apparatus, and exhausts water vapor in each vacuum chamber. There is a case. In this case, the present invention can also be applied to exhaust processing control and regeneration processing control for a plurality of cold traps.
[0027]
In the case of a multi-system using a plurality of cold traps 51,..., As in the case of the multi-system using a plurality of cryopumps 25, 26, 27 shown in FIG. It consists of a control unit. The compressor section includes a compressor body, a solenoid valve, an adsorber, a relay, a timer, a pressure / temperature sensor, and the like, compresses helium gas as a refrigerant, and supplies the compressed helium gas to each cold trap 51. The control unit controls the operation of the compression unit and each cold trap 51.
[0028]
As described above, even in the multi-system using the plurality of cold traps 51,..., The operation of each cold trap 51,... And the operation of the compressor are centrally controlled by one CPU mounted on the control unit. It is possible to simplify the exhaust processing control and regeneration processing control of each cold trap 51,... And the compressor operation control program, thereby enabling finer control. Further, a communication line for monitoring the states of the cold traps 51,. Therefore, the cost can be reduced, and malfunctions caused by noise can be reduced to obtain high reliability.
[0029]
Further, there is no need to mount a control device on each of the cold traps 51,... Therefore, the space of the semiconductor manufacturing apparatus to which each cold trap 51,... Is connected is not compressed.
[0030]
【The invention's effect】
As is clear from above, the control apparatus for a vacuum pump of the invention according to claim 1, provided with only one control unit which controls a plurality of vacuum pumps to the compressor unit, the compressor body start-stop operation and Since the operation including the protection operation is also controlled, the operations of a plurality of vacuum pumps and compressors can be controlled by the one control unit. Therefore, the control program for each of the vacuum pumps and the compressor main body can be simplified, and fine control can be performed by the simplified amount. Further, it is possible to eliminate the need for communication lines for monitoring the states of the vacuum pumps, eliminate malfunctions due to noise, eliminate the need for noise countermeasures, and reduce costs. Furthermore, the enlargement of each vacuum pump can be prevented.
[0031]
That is, according to the present embodiment, it is possible to provide a control device for a vacuum pump that can improve reliability and simplify the structure.
[0032]
Further, in the vacuum pump control device according to the second aspect of the present invention, an amplifier is provided in a cable for transmitting a detection signal from each sensor provided in each vacuum pump to the control unit. Can be amplified by the amplifier, and can be prevented from being attenuated by transmission or from deteriorating the SN ratio. Therefore, according to the present invention, the temperature and the degree of vacuum of each vacuum pump can be accurately detected even when the distance between each vacuum pump and the control unit is increased.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a control device for a vacuum pump according to the present invention.
FIG. 2 is a schematic view of a cold trap as another example of a vacuum pump.
FIG. 3 is a configuration diagram of a conventional cryopump control device.
[Explanation of symbols]
21 ... Semiconductor manufacturing equipment, 22, 23, 24 ... Vacuum chamber,
25, 26, 27 ... Cryo pump, 28 ... Compressor unit,
29 ... Compressor part, 30 ... Control part,
31 ... Compressor body 32,34 ... I / O port,
33 ... Cryo pump drive unit, 35 ... Compressor drive unit,
36 ... CPU, 37 ... communication port,
38,39,40 ... Gate valve, 51 ... Cold trap.

Claims (2)

A plurality of vacuum pumps (25, 26, 27), such as cryopumps or cold traps, that evacuate the vacuum chamber by freezing and collecting the gas in the vacuum chamber on a panel cooled to a cryogenic temperature;
Each of the vacuum pumps (25, 26, 27) is provided in a compressor unit (28) on which a compressor body (31) for supplying a compressed refrigerant to the respective vacuum pumps (25, 26, 27) is mounted. ) and comprising only one control unit for controlling the operation of the compressor body (31) and (30) the <br/>,
The control unit ( 30 ) includes an operation including an evacuation processing operation and a regeneration processing operation of each of the vacuum pumps ( 25 , 26 , 27 ) , a start / stop operation and a protection operation of the compressor body ( 31 ). A control device for a vacuum pump, wherein the operation is centrally controlled . In the vacuum pump control device according to claim 1,
A sensor provided in each of the vacuum pumps (25, 26, 27);
Amplifiers (45, 46, 47) interposed in cables (42, 43, 44) for transmitting detection signals from the respective sensors to the control unit (30).
A control device for a vacuum pump.

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