US20090126374A1

US20090126374A1 - Cryopump apparatus and operation method therefor

Info

Publication number: US20090126374A1
Application number: US12/260,439
Authority: US
Inventors: Tokumitsu Arai; Kazutoshi Aoki; Isao Mochizuki
Original assignee: Canon Anelva Technix Corp
Current assignee: Canon Anelva Corp
Priority date: 2007-11-01
Filing date: 2008-10-29
Publication date: 2009-05-21
Also published as: CN101424257A; JP4791520B2; JP2009133304A; CN101424257B

Abstract

A cryopump apparatus includes a sensor which detects at least one of the temperature and pressure in a cryopump, a controller which detects a change in at least one of the temperature and pressure in the cryopump on the basis of the detection result obtained by the sensor, thereby determining the connection state between the controller and the cryopump, and a display device which displays an abnormal point for the cryopump estimated from the determination result obtained by the controller.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a cryopump apparatus having a cryopump which drives a refrigerator to exhaust a gas in a vessel as the exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls its operation and exhaust performance, and an operation method therefor.
2. Description of the Related Art
A vacuum exhaust system including a cryopump or cryotrap and a controller is often used as a vacuum processing apparatus represented by a semiconductor manufacturing apparatus. In particular, a general vacuum processing apparatus for the semiconductor manufacture has a structure in which a large number of vacuum chambers are partitioned with valves. One cryopump or cryotrap is mounted in each of these vacuum chambers. Therefore, several to several tens of cryopumps or cryotraps are mounted per apparatus.
The cryopump or cryotrap has a refrigerator, a temperature sensor for measuring the temperature of its internal space, and a pressure sensor for measuring the pressure of its internal space. Cables for supplying power to the respective devices and those for reading out the values output from the sensors are necessary.
The cryopump or cryotrap is a so-called storage type vacuum pump. This pump requires so-called regeneration for discharging the stored gas. In addition, this pump has a property that it cannot cool down to a temperature at which vacuum exhaust is possible unless it is temporarily roughed out to a certain pressure by a roughing vacuum pump after the regeneration. For this reason, the cryopump has a plurality of valves such as a purge valve for introducing a purge gas to its inside in regeneration, a roughing valve for roughing it out, and a discharge valve for discharging a gas generated upon vaporization due to the regeneration to its outside as needed.
Cables for opening/closing these valves are accordingly necessary.
The cryopump or cryotrap often includes a heater to shorten the regeneration time. In this case, a cable for supplying power to the heater is also necessary.
These wiring lines are connected between the cryopump or cryotrap and the controller to extend in the vacuum processing apparatus. FIGS. 11 and 12 show such states.
The cryopump apparatus shown in FIG. 11 includes one cryopump 2 a and a controller 1 which controls it.
The cryopump 2 a includes a temperature sensor 3, a heater 4, a pressure sensor 5, a purge valve 6 connected to a purge gas supply pipe, a roughing valve 7 connected to a pipe which communicates with a roughing vacuum pump 17, and a refrigerator 9. The cryopump 2 a also includes a discharge valve 8 for discharging a gas or liquid from its inside to its outside.
The following cables 10 to 16 are connected between the cryopump 2 a and the controller 1. That is, a temperature sensor cable 10 for measuring the temperature in the cryopump 2 a by the temperature sensor 3, a heater cable 11 for supplying power to the heater 4, and a pressure sensor cable 12 for measuring the pressure in the cryopump 2 a by the pressure sensor 5 are connected. A purge valve opening/closing cable 13 for opening/closing the purge valve 6, and a roughing valve opening/closing cable 14 for opening/closing the roughing valve 7 are also connected. A discharge valve opening/closing cable 15 for opening/closing the discharge valve 8, and a refrigerator driving cable 16 for driving the refrigerator 9 are also connected. The roughing vacuum pump 17 is connected to a roughing pipe connected to the roughing valve 7.
The cryopump apparatus shown in FIG. 12 includes two cryopumps 2 a and 2 b and a controller 1 which controls them. The cryopumps 2 a and 2 b have the same configuration as that of the cryopump 2 a described above, and cables 10 to 16 identical to those described above are connected to the controller 1.
Japanese Patent Laid-Open No. 2001-317457, for example, discloses the above-described cryopump apparatus and an operation method therefor.
A vacuum processing apparatus which mounts a cryopump apparatus including a plurality of cryopumps and a controller as described above often has a large, complicated structure. Also, the cryopumps and controller are often set at a great distance, which makes it hard to wire them.
Wiring is generally performed in accordance with a wiring diagram by writing wiring names at the two ends to prevent any faulty connection. Nevertheless, wiring errors sometimes occur when an enormous number of wiring lines are connected in similar patterns.
After the wiring operation, the cryopump apparatus is activated. Note that if a plurality of cryopumps are activated at once, they often start up while any wiring errors remain unspecified. In this case, normal control cannot be performed in subsequent regeneration, which may damage the apparatus.
A case in which the temperature sensor cables 10 are incorrectly connected to the two cryopumps 2 a and 2 b as shown in FIG. 12 will be considered. In this case, when no large difference in, for example, a change in temperature between the two cryopumps 2 a and 2 b is detected upon activating the cryopumps 2 a and 2 b at once, they continue operation without noticing faulty wiring. After that, for example, one of the two cryopumps 2 a and 2 b is regenerated using a heating means such as the heater 4 without noticing the fact that the temperature sensors 3 are incorrectly wired. In this case, despite a rise in the actual temperature in the regenerated cryopump, temperature measurement is performed for the other cryopump with a low temperature. For this reason, the controller 1 detects the temperature in the regenerated cryopump as being kept low. If this state is prolonged, the cryopump regenerated using the heating means may be damaged after an excessive rise in temperature.
Other wiring errors, if any, may cause troubles: for example, the valve opens or the cryopump starts regeneration or stops at an unintended timing.
The above-described situations are typically encountered when a cryopump is used, but the same applies a case in which a cryotrap is used.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above-described problem, and has as its object to prevent, for example, any faulty-wiring-related troubles and erroneous operations by detecting faulty wiring of a cryopump apparatus having a plurality of cryopumps and a controller.
According to one aspect of the present invention, there is provided a cryopump apparatus including a cryopump which drives a refrigerator to exhaust a gas in a vessel as an exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls an operation and exhaust performance thereof, comprising:
detection means for detecting at least one of a temperature and pressure in the cryopump;
determination means for detecting a change in at least one of the temperature and pressure in the cryopump on the basis of the detection result obtained by the detection means, thereby determining a connection state between the controller and the cryopump; and
display means for, if the determination means determines that there is an abnormality of the connection state, displaying an estimated abnormal point for the cryopump.
According to another aspect of the present invention, there is provided an operation method for a cryopump apparatus including a cryopump which drives a refrigerator to exhaust a gas in a vessel as an exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls an operation and exhaust performance thereof, the cryopump including detection means for detecting at least one of a temperature and pressure, comprising:
a detection step of detecting a change in at least one of the temperature and pressure in the cryopump by the detection means;
a determination step of determining, by the controller, a connection state between the controller and a predetermined cryopump on the basis of the detection result obtained in the detection step; and a display step of, if it is determined in the determination step that there is an abnormality of the connection state, displaying an estimated abnormal point for the predetermined cryopump on display means.
According to the present invention, it is possible to prevent, for example, any faulty-wiring-related troubles and erroneous operations by detecting faulty wiring of a cryopump apparatus having a plurality of cryopumps and a controller.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a connection diagram of a cryopump apparatus including a plurality of cryopumps and a controller according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating an operation for determining the connection states between the cryopumps and the controller by the controller shown in FIG. 1;

FIG. 3 is a flowchart illustrating the operation of the controller continued to FIG. 2;

FIG. 4 is a flowchart illustrating the operation of the controller continued to FIG. 3;

FIG. 5 is a flowchart illustrating the operation of the controller continued to FIG. 4;

FIG. 6 is a flowchart illustrating the operation of the controller continued to FIG. 5;

FIG. 7 is a flowchart illustrating the operation of the controller continued to FIG. 6;

FIG. 8 is a flowchart illustrating the operation of the controller continued to FIG. 7;

FIG. 9 is a flowchart illustrating the operation of the controller continued to FIG. 8;

FIGS. 10A and 10B are tables for explaining abnormal statuses obtained by the operation of the controller shown in FIGS. 2 to 9;

FIG. 11 is a connection diagram of a cryopump apparatus including one cryopump and a controller according to a prior art; and

FIG. 12 is a connection diagram of a cryopump apparatus including two cryopumps and a controller according to a prior art.

DESCRIPTION OF THE EMBODIMENT

A cryopump apparatus and an operation method therefor according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In this embodiment, the present invention is applied to a cryopump apparatus having a cryopump which drives a refrigerator to exhaust a gas in a vessel as the exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls its operation and exhaust performance. However, the present invention is not particularly limited to this, and may be applied to a vacuum exhaust system having a cryotrap and a controller which is connected to the cryotrap and controls its operation and exhaust performance. The same reference numerals as in the cryopump apparatuses according to the prior arts denote the same constituent elements, and a description thereof will be simplified or not be given.
FIG. 1 is a connection diagram of a cryopump having a plurality of cryopumps 2 a, 2 b, . . . , 2 c and a controller 1 which is connected to them and controls their operations and exhaust performances.
The cryopump apparatus includes a detection means for detecting at least one of the temperature and pressure (temperature sensor and pressure sensor) in each of the cryopumps 2 a, 2 b, . . . , 2 c. The controller 1 detects a change in at least one of the temperature and pressure in each of the cryopumps 2 a, 2 b, . . . , 2 c by the detection means, thereby determining the connection states between the controller 1 and predetermined cryopumps 2 a, 2 b, . . . , 2 c. Details of this determination will be explained below. Also, the controller 1 can display, on a display device 100, abnormal points for the predetermined cryopumps estimated from the determination results.
Each of the cryopumps 2 a, 2 b, . . . , 2 c includes a temperature sensor 3, a heater 4, a pressure sensor 5, a purge valve 6 connected to a purge gas supply pipe, a roughing valve 7 connected to a pipe which communicates with a roughing vacuum pump 17, and a refrigerator 9. The temperature sensor 3 and pressure sensor 5 configure a detection means. Each of the cryopumps 2 a, 2 b, . . . , 2 c also includes a discharge valve 8 for discharging a gas or liquid from inside each of the cryopumps 2 a, 2 b, . . . , 2 c (inside each of vacuum pumps) to its outside.
The following cables 10 to 16 are connected between each of the cryopumps 2 a, 2 b, . . . , 2 c and the controller 1. That is, a temperature sensor cable 10 for measuring the temperature in the cryopump by the temperature sensor 3, a heater cable 11 for supplying power to the heater 4, and a pressure sensor cable 12 for measuring the pressure in the cryopump by the pressure sensor 5 are connected. A purge valve opening/closing cable 13 for opening/closing the purge valve 6, and a roughing valve opening/closing cable 14 for opening/closing the roughing valve 7 connected to the roughing vacuum pump 17 are also connected. A discharge valve opening/closing cable 15 for opening/closing the discharge valve 8, and a refrigerator driving cable 16 for driving the refrigerator 9 are also connected. A roughing pipe connected to the roughing valve 7 is connected to the roughing vacuum pump 17. This configuration is the same as those shown in FIGS. 11 and 12 described above.
That is, the controller 1 is connected to the temperature sensor 3 in each of the cryopumps 2 a, 2 b, . . . , 2 c via the temperature sensor cable 10, and connected to the heater 4 via the heater cable 11. The controller 1 is also connected to the pressure sensor 5 via the pressure sensor cable 12, connected to the purge valve 6 via the purge valve opening/closing cable 13, and connected to the roughing valve 7 via the roughing valve opening/closing cable 14. The controller 1 is also connected to the discharge valve 8 via the discharge valve opening/closing cable 15, and connected to the refrigerator 9 via the refrigerator driving cable 16.
The temperature sensor 3 measures the temperature in each of the cryopumps 2 a, 2 b, . . . , 2 c, and provides the temperature measurement value to the controller 1 via the temperature sensor cable 10. This allows the controller 1 to monitor the temperatures in the cryopumps 2 a, 2 b, . . . , 2 c.
Supplying an electric current to the heater 4 via the heater cable 11 allows the controller 1 to electrically control the ON/OFF operation of the heater 4.
The pressure sensor 5 measures the pressure in each of the cryopumps 2 a, 2 b, . . . , 2 c, and provides the pressure measurement value to the controller 1 via the pressure sensor cable 12. This allows the controller 1 to monitor the pressures in the cryopumps 2 a, 2 b, . . . , 2 c.
The purge valve 6 receives a control signal from the controller 1 via the purge valve opening/closing cable 13. This allows the controller 1 to electrically control the opening/closing operation (ON/OFF operation) of the purge valve 6.
The roughing valve 7 receives a control signal from the controller 1 via the roughing valve opening/closing cable 14. This allows the controller 1 to electrically control the opening/closing operation (ON/OFF operation) of the roughing valve 7.
The discharge valve 8 receives a control signal from the controller 1 via the discharge valve opening/closing cable 15. This allows the controller 1 to electrically control the opening/closing operation (ON/OFF operation) of the discharge valve 8.
Supplying an electric current to the refrigerator 9 via the refrigerator driving cable 16 allows the controller 1 to control the refrigeration operation of the refrigerator 9.
Of the above-described constituent elements, the heater 4, purge valve 6, roughing valve 7, discharge valve 8, and refrigerator 9 correspond to controlled devices the operations of which are controlled by the controller according to the present invention, and the temperature sensor 3 and pressure sensor 5 correspond to the detection means according to the present invention. The heater cable 11, purge valve opening/closing cable 13, roughing valve opening/closing cable 14, discharge valve opening/closing cable 15, and refrigerator driving cable 16 correspond to the controlled device cables. The temperature sensor cable 10 and pressure sensor cable 12 correspond to the sensor cables according to the present invention.
In this embodiment, a control program for confirming that there is no faulty wiring between the controller 1 and the plurality of cryopumps 2 a, 2 b, . . . , 2 c is installed in the controller 1 in advance. The controller 1 implements a function of confirming that the cables 10 to 16 are connected without any errors and omissions by executing the control program as the connection states are changed upon installing or modifying the cryopump apparatus. The confirmation result can be provided to an output device (not shown) such as a display device to notify the operator of it.
An operation according to this embodiment will be explained with reference to FIGS. 2 to 10. For the sake of convenience, the following description will be given assuming three cryopumps 2 a, 2 b, and 2 c as the plurality of cryopumps 2 a, 2 b, . . . , 2 c.
FIGS. 2 to 9 are flowcharts illustrating an example of an operation method of determining the connection states of the cables 10 to 16 between the three cryopumps 2 a, 2 b, and 2 c and the controller 1 (confirming that there is no faulty wiring or the like) by the controller 1. A control program (operation program) for determining the connection state illustrated in the flowcharts of FIGS. 2 to 9 is stored in a memory (e.g., a ROM (Read Only Memory)) in the controller 1 in advance.
FIGS. 10A and 10B are tables showing an abnormal status table for estimating abnormal points from the detection results (ON states) of a plurality of (seven in the example shown in FIGS. 10A and 10B) abnormal statuses A1 to A7 which can be detected by the above-described operation of the controller 1 (to be described later). The abnormal status table shown in FIGS. 10A and 10B are stored to be rewritable in a memory (e.g., a RAM (Random Access Memory)) in the controller 1. The controller 1 serves as a determination means and detects a change in at least one of the temperature and pressure in a predetermined cryopump on the basis of the detection result obtained by a sensor which configures a detection means, thereby determining the connection state between the controller and the predetermined cryopump. The controller 1 serves as a display control means and can display, on the display device 100, abnormal points for the predetermined cryopump estimated from the above-described determination result.
Referring to FIG. 2, first, the controller 1 starts executing the control program, and then monitors the temperatures and pressures in the cryopumps 2 a, 2 b, and 2 c detected by their temperature sensors 3 and pressure sensors 5, respectively (step S1). The connection state determination operation is executed in the order of the cryopumps 2 a, 2 b, and 2 c (steps S2 to S4).
The operation of the cryopump 2 a will be representatively explained with reference to FIGS. 3 to 9, but the same applies to the other cryopumps 2 b and 2 c.
Referring to FIG. 3, the controller 1 starts executing the control program for determining the connection state described above, and starts the operation of the cryopump 2 a. In this start operation, first, the controller 1 turns on the refrigerator 9 of the cryopump 2 a via the refrigerator driving cable 16 to start a refrigeration operation, while measuring, via the temperature sensor cable 10, the temperature in the cryopump 2 a detected by its temperature sensor 3 (step S11). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether the temperature in the cryopump 2 a alone drops by a temperature difference ΔT1 serving as a preset reference value within a timer time t1 serving as a preset reference value (step S12). Note that the timer time t1 and temperature difference ΔT1 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S12, the controller 1 determines that the temperature sensor cable 10 and refrigerator driving cable 16 of the cryopump 2 a are connected correctly (step S13), and turns off the refrigerator 9 of the cryopump 2 a to stop the refrigeration operation (step S14).
If NO in step S12, the temperature in the cryopump 2 a has not dropped by ΔT1 or those in the other cryopumps 2 b and 2 c have dropped by ΔT1 within the timer time t1 (step S15). In this case, the controller 1 determines that there is faulty wiring of the temperature sensor cable 10 or refrigerator driving cable 16 of the cryopump 2 a (step S16). The controller 1 then turns on the abnormal status A1 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S17), and the process shifts to step S14 described above.
In this manner, it is possible to confirm that the temperature sensor cable 10 and refrigerator driving cable 16 are connected to the same cryopump 2 a by monitoring, by the controller 1, a drop in the temperature in the cryopump 2 a detected by its temperature sensor 3.
Referring to FIG. 4, the controller 1 turns on and opens the roughing valve 7 connected to the roughing valve opening/closing cable 14, while measuring, via the pressure sensor cable 12, the pressure in the cryopump 2 a detected by its pressure sensor 5 (step S21). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether the pressure in the cryopump 2 a alone drops by a pressure difference ΔP1 serving as a preset reference value within a timer time t2 serving as a present reference value (step S22). Note that the timer time t2 and pressure difference ΔP1 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S22, the controller 1 determines that the pressure sensor cable 12 and roughing valve opening/closing cable 14 of the cryopump 2 a are connected correctly, the roughing valve 7 operates normally, and the roughing vacuum pump 17 is operating normally (step S23). The controller 1 then turns off and closes the roughing valve 7 of the cryopump 2 a (step S24).
If NO in step S22, the pressure in the cryopump 2 a has not dropped by API or those in the other cryopumps 2 b and 2 c have dropped by ΔP1 within the timer time t2 (step S25). In this case, the controller 1 determines that there is faulty wiring of the pressure sensor cable 12 or roughing valve opening/closing cable 14 of the cryopump 2 a, the roughing valve 7 has broken down, or the roughing vacuum pump 17 is not operating normally (step S26). The controller 1 then turns on the abnormal status A2 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S27), and the process shifts to step S24 described above.
In this manner, it is possible to confirm the following details by monitoring, by the controller 1, a drop in the pressure in the cryopump 2 a detected by its pressure sensor 5 (pressure drop) within a predetermined time. That is, it is possible to confirm that the pressure sensor cable 12 and roughing valve opening/closing cable 14 are connected to the same cryopump 2 a, the roughing valve 7 operates normally, and the roughing vacuum pump 17 is operating normally.
Referring to FIG. 5, after closing the roughing valve 7, the controller 1 turns on and opens the purge valve 6 connected to the purge valve opening/closing cable 13, while measuring, via the pressure sensor cable 12, the pressure in the cryopump 2 a detected by its pressure sensor 5 (step S31). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether the pressure in the cryopump 2 a alone rises by a pressure difference ΔP2 serving as a preset reference value within a timer time t3 serving as a preset reference value (step S32). Note that the timer time t3 and pressure difference ΔP2 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S32, the controller 1 determines that the pressure sensor cable 12 and purge valve opening/closing cable 13 of the cryopump 2 a are connected correctly, the purge valve 6 operates normally, and a purge gas is being supplied to the primary side of the purge valve 6 (step S33). The controller 1 then turns off and closes the purge valve 6 of the cryopump 2 a (step S34).
If NO in step S32, the pressure in the cryopump 2 a has not risen by ΔP2 or those in the other cryopumps 2 b and 2 c has risen within the timer time t3 (step S35). In this case, the controller 1 determines that there is faulty wiring of the pressure sensor cable 12 or purge valve opening/closing cable 13 of the cryopump 2 a, the purge valve 6 has broken down, or a purge gas is not being supplied to the primary side of the purge valve 6 (step S36). The controller 1 then turns on the abnormal status A3 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S37), and the process shifts to step S34 described above.
In this manner, it is possible to confirm the following details by monitoring, by the controller 1, a rise in the pressure in the cryopump 2 a detected by its pressure sensor 5 (pressure rise) within a predetermined time. That is, it is possible to confirm that the pressure sensor cable 12 and purge valve opening/closing cable 13 are connected to the same cryopump 2 a, the purge valve 6 operates normally, and a purge gas is being supplied to the primary side of the purge valve 6.
Referring to FIG. 6, when the discharge valve 8 is attached to the cryopump 2 a, the controller 1 turns on and opens the purge valve 6 to sufficiently purge the inside of the cryopump 2 a, and thereafter turns off and closes the purge valve 6. The controller 1 then turns on and opens the discharge valve 8 connected to the discharge valve opening/closing cable 15, while measuring, via the pressure sensor cable 12, the pressure in the cryopump 2 a detected by its pressure sensor 5 (step S41). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether the pressure in the cryopump 2 a alone drops by a preset pressure difference ΔP3 within a preset timer time t4 (step S42). Note that the timer time t4 and pressure difference ΔP3 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S42, the controller 1 determines that the pressure sensor cable 12 and discharge valve opening/closing cable 15 of the cryopump 2 a are connected correctly, the discharge valve 8 operates normally, and the pressure on the secondary side of the discharge valve 8 is equal to or less than the atmospheric pressure (step S43). The controller 1 then turns off and closes the discharge valve 8 of the cryopump 2 a (step S44).
If NO in step S42, the pressure in the cryopump 2 a has not dropped by ΔP3 or those in the other cryopumps 2 b and 2 c have dropped by ΔP3 within the timer time t4 (step S45). In this case, the controller 1 determines that there is faulty wiring of the pressure sensor cable 12 or discharge valve opening/closing cable 15 of the cryopump 2 a, the discharge valve 8 has broken down, or the pressure on the secondary side of the discharge valve 8 is more than the atmospheric pressure (step S46). The controller 1 then turns on the abnormal status A4 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S47), and the process shifts to step S44 described above.
In this manner, it is possible to confirm the following details by monitoring, by the controller 1, a drop in the pressure in the cryopump 2 a detected by its pressure sensor 5. That is, it is possible to confirm that the pressure sensor cable 12 and discharge valve opening/closing cable 15 are connected to the same cryopump 2 a, the discharge valve 8 operates normally, and the pressure on the secondary side of the discharge valve 8 is equal to or less than the atmospheric pressure.
Referring to FIG. 7, the controller 1 stops the operation of the cryopump 2 a, and turns on the heater 4 and supplies an electric current to the heater 4 via the heater cable 11 while measuring, via the temperature sensor cable 10, the temperature in the cryopump 2 a detected by its temperature sensor 3 (step S51). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether the temperature in the cryopump 2 a alone rises by a preset temperature difference ΔT2 within a preset timer time t5 (step S52). Note that the timer time t5 and temperature difference ΔT2 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S52, the controller 1 determines that the temperature sensor cable 10 and heater cable 11 of the cryopump 2 a are connected correctly, and the heater 4 operates normally (step S53). The controller 1 then turns off and closes the heater 4 of the cryopump 2 a (step S54).
If NO in step S52, the temperature in the cryopump 2 a has not risen by ΔT2 or those in the other cryopumps 2 b and 2 c have risen by ΔT2 within the timer time t5 (step S55). In this case, the controller 1 determines that there is faulty wiring of the temperature sensor cable 10 or heater cable 11 of the cryopump 2 a, or the heater 4 has broken down (step S56). The controller 1 then turns on the abnormal status A5 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S57), and the process shifts to step S44 described above.
In this manner, it is possible to confirm that the temperature sensor cable 10 and heater cable 11 are connected to the same cryopump 2 a, and the heater 4 operates normally by monitoring, by the controller 1, an increase in the measurement value obtained by the temperature sensor 3.
Referring to FIG. 8, the controller 1 makes the internal temperature of the cryopump 2 a different from the temperature of the environment in which the cryopump apparatus is installed by a preset temperature difference ΔT3 (step S61). The controller 1 then turns on and opens the roughing valve 7 while measuring the temperature in the cryopump 2 a detected by its temperature sensor 3 (step S62). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether a change in the temperature of the cryopump 2 a within a preset timer time t6 is equal to or less than a preset temperature difference ΔT4 (step S63). Note that the timer time t6 and temperature difference ΔT4 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S63, the controller 1 determines that the roughing valve opening/closing cable 14 and temperature sensor cable 10 of the cryopump 2 a are connected correctly, the roughing valve 7 operates normally, and the roughing vacuum pump 17 is operating normally (step S64). The controller 1 then turns off and closes the roughing valve 7 of the cryopump 2 a (step S65).
If NO in step S63, the change in the temperature of the cryopump 2 a within the timer time t6 is more than ΔT4 or the change in the temperatures of the other cryopumps 2 b and 2 c within the timer time t6 is equal to or less than ΔT4 (step S66). In this case, the controller 1 determines that there is faulty wiring of the roughing valve opening/closing cable 14 or temperature sensor cable 10 of the cryopump 2 a, or the roughing valve 7 or roughing vacuum pump 17 has broken down (step S67). The controller 1 then turns on the abnormal status A6 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S68), and the process shifts to step S65 described above.
In this manner, it is possible to confirm the following details by monitoring, by the controller 1, whether a change in temperature subsequent to step S62 is fast or slow. That is, it is possible to confirm again that the roughing valve opening/closing cable 14 and temperature sensor cable 10 are connected to the same cryopump 2 a, the roughing valve 7 operates normally, and the roughing vacuum pump 17 connected to the roughing valve 7 is operating normally.
Referring to FIG. 9, the controller 1 makes the internal temperature of the cryopump 2 a different from the temperature of the environment in which the cryopump apparatus is installed by a preset temperature difference ΔT3 (step S71). The controller 1 then turns on and opens the purge valve 6 while measuring the temperature in the cryopump 2 a detected by its temperature sensor 3 (step S72). At this time, the controller 1 does not perform the same operation for the other cryopumps 2 b and 2 c.
Next, the controller 1 checks whether a change in the temperature of the cryopump 2 a within a preset timer time t7 is equal to or more than a preset temperature difference ΔT5 (step S73). Note that the timer time t7 and temperature difference ΔT5 are stored in, for example, the memory in the controller 1 in advance.
If YES in step S73, the controller 1 determines that the purge valve opening/closing cable 13 and temperature sensor cable 10 of the cryopump 2 a are connected correctly, the purge valve 6 operates normally, and a purge gas is being supplied to the primary side of the purge valve 6 (step S74). The controller 1 then turns off and closes the purge valve 6 of the cryopump 2 a (step S75).
If NO in step S73, the change in the temperature of the cryopump 2 a within the timer time t7 is less than ΔT5 or that in those of the other cryopumps 2 b and 2 c within the timer time t7 is equal to or more than ΔT5 (step S76). In this case, the controller 1 determines that there is faulty wiring of the purge valve opening/closing cable 13 or temperature sensor cable 10 of the cryopump 2 a, the purge valve 6 has broken down, or a purge gas is not being supplied to the primary side of the purge valve 6 (step S77). The controller 1 then turns on the abnormal status A7 corresponding to the cryopump 2 a in the abnormal status table shown in FIGS. 10A and 10B (step S78), and the process shifts to step S75 described above.
In this manner, it is possible to confirm the following details by monitoring, by the controller 1, whether a change in temperature subsequent to step S72 is fast or slow. That is, it is possible to confirm again that the purge valve opening/closing cable 13 and temperature sensor cable 10 are connected to the same cryopump 2 a, the purge valve 6 operates normally, and a purge gas is being supplied to the primary side of the purge valve 6.
Referring back to FIG. 2, the controller 1 mounted in the cryopump apparatus performs the above-described operation for the cryopumps 2 a, 2 b, and 2 c without repeating the confirmation of the same details (steps S2 to S4). After that, the controller 1 determines an abnormally on the basis of the obtained abnormal status table (step S5).
FIGS. 10A and 10B show the detection states of the abnormal statuses A1 to A7 of the cryopumps 2 a, 2 b, and 2 c obtained by the above-described operation (presence: ON; absence: −), and abnormal points estimated from their combination patterns Nos. 1 to 19. The details of patterns Nos. 1 to 19 will be explained sequentially.
In case of No. 1, because the cryopumps 2 a, 2 b, and 2 c are detected to be in none of the abnormal statuses A1 to A7, the overall system is estimated to have no abnormality.
In case of No. 2, because the cryopump 2 a is detected to be in the abnormal status A1, the temperature sensor 3, temperature sensor cable 10, or refrigerator driving cable 16 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 3, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A1, the temperature sensor cables 10 or refrigerator driving cables 16 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 4, because the cryopump 2 a is detected to be in the abnormal status A2, the pressure sensor 5, pressure sensor cable 12, roughing valve opening/closing cable 14, or roughing valve 7 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 5, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A2, the pressure sensor cables 12 or roughing valve opening/closing cables 14 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 6, because the cryopumps 2 a, 2 b, and 2 c are detected to be in the abnormal status A2, their roughing vacuum pumps 17 are estimated to have broken down.
In case of No. 7, because the cryopump 2 a is detected to be in the abnormal status A3, the pressure sensor 5, pressure sensor cable 12, purge valve opening/closing cable 13, or purge valve 6 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 8, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A3, the pressure sensor cables 12 or purge valve opening/closing cables 13 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 9, because the cryopumps 2 a, 2 b, and 2 c are detected to be in the abnormal status A3, it is estimated that a purge gas is not being supplied to the primary sides of their purge valves 6.
In case of No. 10, because the cryopump 2 a is detected to be in the abnormal status A4, the pressure sensor 5, pressure sensor cable 12, discharge valve opening/closing cable 15, or discharge valve 8 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 11, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A4, the pressure sensor cables 12 or discharge valve opening/closing cables 15 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 12, because the cryopumps 2 a, 2 b, and 2 c are detected to be in the abnormal status A4, it is estimated that the pressures on the secondary sides of their discharge valves 8 are more than the atmospheric pressure.
In case of No. 13, because the cryopump 2 a is detected to be in the abnormal status A5, the heater 4, heater cable 11, temperature sensor 3, or temperature sensor cable 10 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 14, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A5, the heater cables 11 or temperature sensor cables 10 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 15, because the cryopump 2 a is detected to be in the abnormal status A6, the temperature sensor 3, temperature sensor cable 10, roughing valve opening/closing cable 14, or roughing valve 7 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 16, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A6, the temperature sensor cables 10 or roughing valve opening/closing cables 14 of the cryopumps 2 a and 2 b are estimated to have faulty wiring.
In case of No. 17, because the cryopump 2 a is detected to be in the abnormal status A7, the temperature sensor 3, temperature sensor cable 10, purge valve opening/closing cable 13, or purge valve 6 of the cryopump 2 a is estimated to have an abnormality.
In case of No. 18, because the cryopumps 2 a and 2 b are detected to be in the abnormal status A7, the temperature sensor cables 10 or purge valve opening/closing cables 13 of the cryopump 2 a are estimated to have faulty wiring.
In case of No. 19, because the cryopumps 2 a, 2 b, and 2 c are detected to be in the abnormal status A7, it is estimated that a purge gas is not being supplied to the primary sides of their purge valves 6.
The use of the above-described abnormal status table allows the controller 1 to narrow down the type of abnormality by determining, for example, which cables have faulty wiring or whether there is any faulty wiring or breakdown, depending on which abnormality status is ON. This makes it possible to determine the presence/absence of any faulty wiring and device abnormality of a cryopump apparatus including a plurality of cryopumps and a controller, thus preventing any operation failure and breakdown of each cryopump.
Note that the above-described abnormal statuses A1 to A7 and their combination patterns Nos. 1 to 19 are merely an example, and may be changed as needed in accordance with, for example, the configuration of a cryopump apparatus used actually.
Also, although this embodiment has exemplified a configuration in which the controller 1 can determine the presence/absence of faulty wiring of the cables 10 to 16 and abnormalities of controlled devices connected to them, the present invention is not particularly limited to this. In short, the present invention is applicable to any configuration as long as the cryopump apparatus can determine the connection states between the plurality of cryopumps and the controller by detecting a change in at least one of the temperature and pressure in each cryopump by the detection means.
The controller may have the following function.
First, the controller operates the refrigerator of one cryopump to make its internal temperature different from the temperature of the environment in which the cryopump apparatus is installed by a certain degree. After that, the controller opens the roughing valve or purge valve.
The controller then detects that a subsequent change in temperature is slow if the roughing valve is opened, and that a subsequent change in temperature is fast if the purge valve is opened. With this operation, the controller confirms that the roughing valve opening/closing cable or purge valve opening/closing cable and the temperature sensor cable are connected to the same cryopump. The controller eventually confirms that all of the refrigerator driving cable, temperature sensor cable, roughing valve opening/closing cable, purge valve opening/closing cable, and pressure sensor cable are connected to the same cryopump. This operation is performed for a plurality of cryopumps one by one. With this operation, the controller confirms that the refrigerator driving cables, temperature sensor cables, roughing valve opening/closing cables, purge valve opening/closing cables, and pressure sensor cables are connected between the controller and the plurality of cryopumps without any errors.
Alternatively, the controller may have the following function.
First, the controller heats the heater of one cryopump to make its internal temperature higher than the temperature of the environment in which the cryopump apparatus is installed. At this time, the controller opens the roughing valve or purge valve.
The controller then detects that a subsequent change in temperature is slow if the roughing valve is opened, and that a subsequent change in temperature is fast if the purge valve is opened. With this operation, the controller confirms that the roughing valve opening/closing cable or purge valve opening/closing cable and the temperature sensor cable are connected to the same cryopump. The controller eventually confirms that all of the refrigerator driving cable, heater cable, temperature sensor cable, purge valve opening/closing cable, and pressure sensor cable are connected to the same cryopump. The same operation is performed for a plurality of cryopumps one by one.
With this operation, the controller confirms that the refrigerator driving cables, temperature sensor cables, roughing valve opening/closing cables, purge valve opening/closing cables, and pressure sensor cables are connected between the controller and the plurality of cryopumps without any errors.
As has been described above, the present invention can be used for a cryopump apparatus having a plurality of cryopumps and a controller, and an operation method therefor. The present invention can also be used for a vacuum exhaust system having a cryotrap and a controller, and an operation method therefor.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2007-285230, filed Nov. 1, 2007, which is hereby incorporated by reference herein in its entirety.

Claims

1. A cryopump apparatus including a cryopump which drives a refrigerator to exhaust a gas in a vessel as an exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls an operation and exhaust performance thereof, comprising:

detection means for detecting at least one of a temperature and pressure in the cryopump;

determination means for detecting a change in at least one of the temperature and pressure in the cryopump on the basis of the detection result obtained by said detection means, thereby determining a connection state between the controller and the cryopump; and

display means for, if said determination means determines that there is an abnormality of the connection state, displaying an estimated abnormal point for the cryopump.

2. The apparatus according to claim 1, wherein said determination means operates a refrigerator of a predetermined cryopump, and detects a change in temperature at the time by a temperature sensor which configures said detection means, thereby determining a connection state of a refrigerator driving cable between the refrigerator and the controller, and a connection state of a temperature sensor cable between the refrigerator and the controller.

3. The apparatus according to claim 1, wherein

said determination means opens a roughing valve connected to a pipe which communicates with a roughing vacuum pump of a predetermined cryopump, and detects a drop in temperature at the time by a pressure sensor which configures said detection means, thereby determining a connection state of a roughing valve opening/closing cable between the roughing valve and the controller, and a connection state of a pressure sensor cable between said pressure sensor and the controller, and

said determination means opens a purge valve connected to a purge gas supply pipe of a predetermined cryopump, and detects a rise in pressure at the time by a pressure sensor which configures said detection means, thereby determining a connection state of a purge valve opening/closing cable between the purge valve and the controller, and a connection state of a pressure sensor cable between said pressure sensor and the controller.

4. The apparatus according to claim 1, wherein said determination means generates heat by a heater included in a predetermined cryopump, and detects a change in temperature at the time by a temperature sensor which configures said detection means, thereby determining a connection state of a heater cable between the heater and the controller, and a connection state of a temperature sensor cable between said temperature sensor and the controller.

5. The apparatus according to claim 1, wherein said determination means opens a purge valve connected to a purge gas supply pipe of a predetermined cryopump to raise a pressure in the predetermined cryopump, and thereafter opens a discharge valve to discharge one of a gas and a liquid from inside the predetermined cryopump, and detects a drop in pressure at the time by a pressure sensor which configures said detection means, thereby determining a connection state of a discharge valve opening/closing cable between the discharge valve and the controller, and a connection state of a pressure sensor cable between said pressure sensor and the controller.

6. The apparatus according to claim 1, wherein said determination means operates a refrigerator of a predetermined cryopump to make an internal temperature of the predetermined cryopump different from a temperature of an environment in which the predetermined cryopump is installed by a certain degree, and then opens one of a roughing valve connected to a pipe which communicates with a roughing vacuum pump of the predetermined cryopump and a purge valve connected to a purge gas supply pipe of the predetermined cryopump, and detects, by a temperature sensor which configures said detection means, that a subsequent change in temperature is slow if the roughing valve is opened, and that a subsequent change in temperature is fast if the purge valve is opened, thereby determining a connection state of a purge valve opening/closing cable between the purge valve and the controller, and a connection state of a temperature sensor cable between said temperature sensor and the controller.

7. The apparatus according to claim 1, wherein said determination means generates heat by a heater included in a predetermined cryopump to make an internal temperature of the predetermined cryopump higher than a temperature of an environment in which the predetermined cryopump is installed, and then opens one of a roughing valve connected to a pipe which communicates with a roughing vacuum pump of the predetermined cryopump and a purge valve connected to a purge gas supply pipe of the predetermined cryopump, and detects, by a temperature sensor which configures said detection means, that a subsequent drop in temperature is slow if the roughing valve is opened, and that a subsequent drop in temperature is fast if the purge valve is opened, thereby determining a connection state of a roughing valve opening/closing cable between the roughing valve and the controller, a connection state of a purge valve opening/closing cable between the purge valve and the controller, and a connection state between said temperature sensor and the controller.

8. A vacuum processing apparatus comprising a cryopump apparatus defined in claim 1.

9. An operation method for a cryopump apparatus including a cryopump which drives a refrigerator to exhaust a gas in a vessel as an exhaust target using condensation and adsorption of the gas, and a controller which is connected to the cryopump and controls an operation and exhaust performance thereof, the cryopump including detection means for detecting at least one of a temperature and pressure, comprising:

a detection step of detecting a change in at least one of the temperature and pressure in the cryopump by the detection means;

a determination step of determining, by the controller, a connection state between the controller and a predetermined cryopump on the basis of the detection result obtained in the detection step; and

a display step of, if it is determined in the determination step that there is an abnormality of the connection state, displaying an estimated abnormal point for the predetermined cryopump on display means.