WO2018198288A1

WO2018198288A1 - Pump monitoring device, vacuum processing device, and vacuum pump

Info

Publication number: WO2018198288A1
Application number: PCT/JP2017/016818
Authority: WO
Inventors: 雄介玉井; 陽野田
Original assignee: 株式会社島津製作所
Priority date: 2017-04-27
Filing date: 2017-04-27
Publication date: 2018-11-01
Also published as: CN110546381A; JPWO2018198288A1; US20200141415A1

Abstract

Provided is a pump monitoring device that detects abnormalities in a plurality of vacuum pumps which are connected to the same chamber. The pump monitoring device compares signals indicating the rotation state of the pump rotor of each of the plurality of vacuum pumps, and on the basis of such results, estimates if an abnormality is occurring in any the plurality of vacuum pumps.

Description

Pump monitoring device, vacuum processing device and vacuum pump

The present invention relates to a pump monitoring device, a vacuum processing device, and a vacuum pump.

In processes such as dry etching and CVD in the manufacture of semiconductors and liquid crystal panels, processing is performed in a high-vacuum process chamber. Therefore, as a means for exhausting the gas in the process chamber and maintaining the high vacuum, for example, a turbo molecular pump Such a vacuum pump is used. When the gas in the process chamber such as dry etching or CVD is exhausted, reaction products are deposited in the pump as the gas is exhausted.

Regarding the deposition of such reaction products, Patent Document 1 discloses a method for detecting the products deposited in the pump. In the deposit detection method disclosed in Patent Document 1, a current value of a motor that rotationally drives a rotary body of a pump is measured, and a warning is issued when the amount of change in the measured value with respect to the initial value of the motor current is equal to or greater than a predetermined value. I am doing so.

Japanese Patent No. 5767632

However, in practice, since the exhaust gas flow rate varies greatly even within a single process, the current value of the motor that rotationally drives the rotating body also varies greatly with the variation of the gas flow rate. Therefore, even when the motor current value fluctuates due to fluctuations in the gas flow rate, a warning is issued, and there is a problem that erroneous determination cannot be avoided.

According to the first aspect of the present invention, the pump monitoring device is a pump monitoring device that detects an abnormality of a plurality of vacuum pumps connected to the same chamber, and each of the pump rotors of the plurality of vacuum pumps. Based on the result of comparing the signals representing the rotation state, it is estimated that an abnormality has occurred in any of the plurality of vacuum pumps.
According to a second aspect of the present invention, in the pump monitoring device according to the first aspect, the signal indicating the rotation state is a motor current value of a motor that rotationally drives the pump rotor, and is different from each other in the vacuum pumps. Based on the difference between the motor current values, it is estimated that an abnormality has occurred in any of the plurality of vacuum pumps.
According to a third aspect of the present invention, in the pump monitoring apparatus according to the first aspect, the pump rotor is magnetically levitated and supported by a magnetic bearing, and the signal indicating the rotation state is based on a magnetic bearing control amount of the magnetic bearing. Calculated.
According to the fourth aspect of the present invention, in the pump monitoring apparatus of the first aspect, the rotational state of the plurality of vacuum pumps is represented from one or more vacuum processing apparatuses including a plurality of vacuum pumps that evacuate the chamber. An input unit for inputting a signal is provided, and it is estimated that an abnormality has occurred in any of the plurality of vacuum pumps for each of the vacuum processing apparatuses.
According to a fifth aspect of the present invention, a vacuum processing apparatus includes a chamber, a plurality of vacuum pumps that evacuate the chamber, and the pump monitoring apparatus according to the first aspect.
According to the sixth aspect of the present invention, the vacuum pump has a pump monitoring device according to the first aspect, a pump rotor that is rotationally driven by a motor, and an input to which a signal representing a rotational state from another vacuum pump is input. And the pump monitoring device estimates a pump abnormality by comparing a signal representing the rotational state of the pump rotor with a signal representing the rotational state input from the input unit.

According to the present invention, it is possible to prevent erroneous determination when an abnormality of the vacuum pump is detected.

FIG. 1 is a diagram showing a semiconductor manufacturing apparatus according to the first embodiment. FIG. 2 is a cross-sectional view showing details of the pump body. FIG. 3 is a diagram illustrating an example of a measured motor current value. FIG. 4 is a block diagram showing a vacuum pump and a pump monitoring device. FIG. 5 is a diagram illustrating a configuration of the displacement sensor. FIG. 6 is a flowchart illustrating an example of the abnormality determination process. FIG. 7 is a block diagram illustrating magnetic bearing control. FIG. 8 is a diagram illustrating an example of the XY value. FIG. 9 is a flowchart illustrating an example of the abnormality determination process in the second embodiment. FIG. 10 is a diagram for explaining the third embodiment. FIG. 11 is a diagram for explaining the fourth embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
-First embodiment-
FIG. 1 is a diagram showing a semiconductor manufacturing apparatus 10 according to the first embodiment. The semiconductor manufacturing apparatus 10 is a vacuum processing apparatus such as an etching apparatus. In the example shown in FIG. 1, two vacuum pumps 1 A and 1 B are attached to the process chamber 100, but the present invention can be similarly applied when three or more are attached.

The vacuum pump 1A is attached to the process chamber 100 via a valve 3A, and the vacuum pump 1B is attached to the process chamber 100 via a valve 3B. The semiconductor manufacturing apparatus 10 includes a main controller 110 that controls the entire manufacturing apparatus including the

vacuum pumps

1A and 1B and the

valves

3A and 3B. The main controller 110 includes a monitoring device 4 that monitors whether the

vacuum pumps

1A and 1B are abnormal. The

vacuum pumps

1A and 1B are vacuum pumps of the same model, and each includes a pump body 11 and a controller 12 that drives and controls the pump body 11. Each controller 12 of the

vacuum pumps

1A and 1B is connected to the main controller 110 of the semiconductor manufacturing apparatus 10 via the communication line 40.

FIG. 2 is a cross-sectional view showing details of the pump body 11. The

vacuum pumps

1A and 1B in the present embodiment are magnetic bearing type turbo molecular pumps, and a rotary body R is provided in the pump body 11. The rotating body R includes a pump rotor 14 and a rotor shaft 15 fastened to the pump rotor 14.

The pump rotor 14 is formed with a plurality of rotor blades 14a on the upstream side, and a cylindrical portion 14b constituting a thread groove pump on the downstream side. Corresponding to these, a plurality of fixed blade stators 62 and a cylindrical screw stator 64 are provided on the fixed side. In the example shown in FIG. 2, the screw groove is formed on the screw stator 64 side, but the screw groove may be formed in the cylindrical portion 4b. Each fixed blade stator 62 is placed on the base 60 via a spacer ring 63.

The rotor shaft 15 is magnetically levitated and supported by radial

magnetic bearings

17A and 17B and an axial magnetic bearing 17C provided on the base 60, and is rotated by a motor 16. Each of the magnetic bearings 17A to 17C includes an electromagnet and a displacement sensor, and the floating position of the rotor shaft 15 is detected by the displacement sensor. The rotational speed of the rotor shaft 15 is detected by a rotational speed sensor 18. When the magnetic bearings 17A to 17C are not operating, the rotor shaft 15 is supported by emergency

mechanical bearings

66a and 66b.

A pump casing 61 in which an air inlet 61a is formed is bolted to the base 60. An exhaust port 65 is provided at the exhaust port 60 a of the base 60, and a back pump is connected to the exhaust port 65. When the rotor shaft 15 to which the pump rotor 14 is fastened is rotated at a high speed by the motor 16, the gas molecules on the intake port 61a side are exhausted to the exhaust port 65 side.

The base 60 is provided with a heater 19 and a refrigerant pipe 20 through which a refrigerant such as cooling water flows. In the case of exhausting gas in which reaction products easily accumulate, the heater 19 is turned on and off and the refrigerant flowing through the refrigerant pipe 20 is turned on and off in order to suppress product accumulation on the thread groove pump portion and the downstream rotor blade 14a. For example, the temperature adjustment is performed so that the base temperature in the vicinity of the screw stator fixing portion becomes a predetermined temperature. Although illustration is omitted, the refrigerant pipe 20 is provided with an electromagnetic valve for turning on and off the refrigerant.

Incidentally, the two

vacuum pumps

1A and 1B attached to the same process chamber 100 can be regarded as having almost the same use conditions. In addition, pump maintenance due to deposition of reaction products is also performed at the same timing. For this reason, it is considered that the deposition state of the reaction product in the vacuum pump 1A and the vacuum pump 1B as the usage time elapses is almost the same.

FIG. 3 is a diagram showing an example of measured values of the motor current of the vacuum pump 1A and the vacuum pump 1B, and shows measured values in a state where the deposition of reaction products has progressed. In FIG. 3, the horizontal axis represents time, and the vertical axis represents the motor current value. A line MA indicated by a solid line indicates a motor current value of the vacuum pump 1A, and a line MB indicated by a broken line indicates a motor current value of the vacuum pump 1B. During the period indicated by symbol B, gas is introduced into the process chamber 100, and the motor current values MA and MB are increased.

In the operation state in which the introduction and stop of the gas are repeated as shown in FIG. 3, the motor current value greatly fluctuates as the gas flow rate fluctuates. However, since the

vacuum pumps

1A and 1B are the same type of vacuum pump and use conditions are almost the same, the motor current values MA and MB are almost the same regardless of the change in the gas introduction amount as shown in FIG. The change tendency is shown, and the difference between the motor current values MA and MB is small.

However, in the state where the deposition amount of the reaction product is increased, an instantaneous increase in the motor current value as shown by symbol A in FIG. 3 is observed. This is because when the deposition of reaction products proceeds, the gap between the cylindrical portion 14b and the screw stator 64 shown in FIG. 2 is reduced by the deposit, and when the pump rotor 14 is shaken, the cylindrical portion 14b and the screw stator 64 are accidentally formed. It is estimated that an instantaneous increase in the motor current value occurs. In the example shown in FIG. 3, an instantaneous increase occurs in the motor current value MA of the vacuum pump 1A. Such a phenomenon occurs when the deposition amount of the reaction product becomes excessive, and after a momentary increase in the motor current value occurs, a malfunction due to the deposit (for example, the cylindrical portion 14b and the like in several days to two weeks). It was found that the pump could not be started due to contact with the screw stator 64.

Therefore, in the present embodiment, the difference between the motor current value MA of the vacuum pump 1A and the motor current value MB of the vacuum pump 1B is calculated, and the magnitude of the difference exceeds a preset threshold (for example, FIG. 3), a warning is issued to the user.

FIG. 4 is a block diagram showing the configuration of the

vacuum pumps

1A and 1B provided in the semiconductor manufacturing apparatus 10. As shown in FIG. The

vacuum pumps

1A and 1B are vacuum pumps of the same model. The pump body 11 includes a motor 16, a magnetic bearing 17 and a rotation speed sensor 18, and the controller 12 includes a communication port 21, a magnetic bearing control unit 22, and a motor control unit 23. And a storage unit 24. In FIG. 4, the radial magnetic bearings 17 A and 17 B and the axial magnetic bearing 17 C in FIG. 2 are collectively referred to as a magnetic bearing 17. The main controller 110 includes a pump monitoring device 120, a display unit 130, and a communication port 44.

The motor control unit 23 estimates the rotation speed of the rotor shaft 15 based on the rotation signal detected by the rotation speed sensor 18, and controls the motor 16 to a predetermined target rotation speed based on the estimated rotation speed. Since the load on the pump rotor 14 increases as the gas flow rate increases, the predetermined target rotational speed is maintained by controlling the motor current according to the load. The magnetic bearing 17 includes a bearing electromagnet and a displacement sensor for detecting the floating position of the rotor shaft 15.

FIG. 5 is a diagram showing the configuration of the displacement sensor. The radial magnetic bearing 17A in FIG. 2 is composed of magnetic bearings for two axes, the x-axis and the y-axis, and includes a pair of displacement sensors X1a and X1b for the x-axis and a pair of displacement sensors Y1a and Y1b for the y-axis. I have. Similarly, the radial magnetic bearing 17B of FIG. 2 is composed of magnetic bearings for two axes, the x axis and the y axis, and includes a pair of displacement sensors X2a and X2b with respect to the x axis, and a pair of displacement sensors Y2a with respect to the y axis. , Y2b. Further, the axial magnetic bearing 17C is provided with a displacement sensor z that detects the displacement of the rotor shaft 15 in the axial direction.

Returning to FIG. 4, the magnetic bearing control unit 22 provided in the controller 12 of the vacuum pump 1A includes displacement sensors X1a, X1b, Y1a, Y1b, X2a, X2b, Y2a provided in the pump body 11 of the vacuum pump 1A. , Y2b, z, the respective detection signals are input. Similarly, the magnetic bearing control unit 22 provided in the controller 12 of the vacuum pump 1B includes displacement sensors X1a, X1b, Y1a, Y1b, X2a, X2b, Y2a, Y2b, provided in the pump body 11 of the vacuum pump 1B. Each detection signal is input from z.

Based on the detection signals from the displacement sensors X1a, X1b, Y1a, Y1b, X2a, X2b, Y2a, Y2b, z, the magnetic bearing control unit 22 of the controller 12 is configured so that the rotor shaft 15 is magnetically supported at the target floating position. The exciting current of the magnetic bearing 17 is controlled. The storage unit 24 of the controller 12 stores parameters necessary for motor control and magnetic bearing control, as well as model data of the

vacuum pumps

1A and 1B.

As described above, the pump monitoring device 120 provided in the main controller 110 determines whether or not abnormality (that is, excessive deposition of reaction products) has occurred in the

vacuum pumps

1A and 1B attached to the process chamber 100. It is a device that monitors. Information is exchanged between the controller 12 of the

vacuum pumps

1A and 1B and the main controller 110 by communication. In the example shown in FIG. 4, the case where signals are exchanged by serial communication is shown. The controller 12 is provided with a communication port 21, and the main controller 110 is also provided with a communication port 44. The communication port 21 of the controller 12 is connected to the communication port 44 of the main controller 110 by a communication line 40.

(Description of monitoring method)
The pump monitoring device 120 uses a signal representing the rotation state of each pump rotor 14 as information for detecting an abnormality in the

vacuum pumps

1A and 1B. In the present embodiment, a case will be described in which the motor current values MA and MB of the

vacuum pumps

1A and 1B are used as signals representing the rotation state of the pump rotor 14.

The motor control unit 23 of the controller 12 calculates the rotational speed of the motor 16 based on the detection value of the rotational speed sensor 18, and performs feedback control so that the detected rotational speed becomes the target rotational speed. In a state where a series of processes are performed as shown in FIG. 3, the motor control unit 23 performs steady operation control for maintaining the rotation speed at the rated rotation speed. As described above, since the gas is introduced into the process chamber 100 in the section indicated by the symbol B, the load on the pump rotor 14 increases. Since the motor control unit 23 performs control to maintain the motor rotation speed at the rated rotation speed, the motor current values MA and MB increase as the gas load increases.

The pump monitoring device 120 receives the motor current values MA and MB of the

vacuum pumps

1A and 1B acquired through the communication line 40. The pump monitoring device 120 calculates a difference ΔM (= MA−MB) between the motor current values MA and MB. The pump monitoring device 120 determines that an abnormality occurs when the magnitude | ΔM | of the difference ΔM exceeds a predetermined threshold value α. For example, at time t1 in FIG. 3, the difference ΔM between the motor current values MA and MB satisfies | ΔM | <α, so it is not determined to be abnormal, but at time t2, it is determined to be abnormal because | ΔM |> α. Is done.

The

vacuum pumps

1A and 1B have almost the same use environment, and the reaction product is deposited in almost the same manner. If the accumulated amount of the reaction product becomes excessive, an instantaneous increase in the motor current value estimated to be caused by accidental contact between the cylindrical portion 14b and the screw stator 64 occurs. However, such an increase in the motor current value occurs accidentally, and it is not known which of the

vacuum pumps

1A and 1B occurs. In this embodiment, since the magnitude | ΔM | of the difference ΔM is compared with the threshold value α, even if an abnormality (that is, an increase in the motor current value) occurs in any of the

vacuum pumps

1A and 1B, the abnormality Can be detected.

As the threshold value α, a preset value may be used, or the threshold value α may be set based on the motor current values MA and MB of the

vacuum pumps

1A and 1B that are actually operating. When the threshold value α is set based on the motor current values MA and MB in the operating state, the threshold value α is set based on the motor current values MA and MB in the initial state in which the usage period after the

vacuum pumps

1A and 1B are used is shallow. Alternatively, the threshold value α may be set based on the motor current values MA and MB from the use start time to the abnormality determination time.

In the initial state, the amount of product accumulation is small, so the threshold σ can be set without being affected by product accumulation. Further, in the initial state, the instantaneous increase in the motor current value as indicated by the symbol A in FIG. 3 hardly occurs. The pump monitoring device 120 acquires a large amount of data over time with respect to the motor current values MA and MB, and calculates the standard deviation σ of the difference ΔM based on these data. Since | ΔM | at the time of abnormality is much larger than | ΔM | at the time of normality, a larger value such as 6σ, for example, is set as the threshold with respect to the standard deviation σ in order to avoid erroneous detection.

FIG. 6 is a flowchart illustrating an example of an abnormality determination process performed by the pump monitoring device 120. In step S100, a threshold value α based on the initial motor current values MA and MB is set. Specifically, after the

vacuum pumps

1A and 1B are attached to the process chamber 100, the motor current values MA and MB are sampled at regular time intervals in an initial state from the start of pump operation to a predetermined period. In this case, the motor current values MA and MB are sampled at the same timing. A difference ΔM = MA−MB is obtained for the obtained plural pairs of motor current values MA and MB, and a standard deviation σ of the difference ΔM is calculated. Then, 6σ is set as the threshold value α. The threshold α = 6σ is stored in a storage unit (not shown) provided in the pump monitoring device 120 of FIG.

Next, the motor current values MA and MB are read in step S110, and the magnitude | ΔM | of the difference ΔM is calculated in the subsequent step S120. In step S130, it is determined whether the magnitude relationship between | ΔM | and the threshold value α is | ΔM |> α. If it is determined in step S130 that | ΔM |> α, the process proceeds to step S140 to execute a warning process. For example, a warning is displayed on the display unit 130 of the main controller 110 to inform the user that maintenance of the

vacuum pumps

1A and 1B attached to the process chamber 100 is necessary.

On the other hand, if it is determined that | ΔM | ≦ α in step S130, the process returns to step S110, and the processes from step S110 to step S130 are executed again. The processing from step S110 to step S130 is repeatedly executed at predetermined time intervals until it is determined yes in step S130.

(C1) As described above, the pump monitoring device 120 that detects an abnormality in the plurality of

vacuum pumps

1A and 1B connected to the same process chamber 100 has the pump rotor 14 of each of the plurality of

vacuum pumps

1A and 1B. It is estimated that an abnormality has occurred in one of the

vacuum pumps

1A and 1B based on the result of comparing the signals representing the rotation states of the

vacuum pumps

1A and 1B.

Since the

vacuum pumps

1A and 1B are connected to the same process chamber 100, the pump state such as the deposition amount of the reaction product is almost the same, and even if the motor current value fluctuates due to the fluctuation of the gas flow rate, the pump rotor The signals representing the 14 rotational states show the same tendency. Therefore, by comparing the signals representing the rotational state, when the signals representing the rotational state (motor current values MA and MB in the example of FIG. 3) deviate from each other as at time t2 in FIG. It can be easily estimated that an abnormality has occurred in either of the

vacuum pumps

1A and 1B, and a conventional erroneous determination can be prevented.

(C2) For example, the motor current values MA and MB of the motor 16 that rotationally drives the pump rotor 14 can be used as a signal representing the above-described rotation state. In this case, based on the difference between the motor current values MA and MB of the

vacuum pumps

1A and 1B different from each other, for example, the magnitude | ΔM | It is estimated that an abnormality has occurred in either

pump

1A or 1B.

(C5) Further, as shown in FIG. 1, the above-described pump monitoring apparatus 120 is added to the semiconductor manufacturing apparatus 10 which is a vacuum processing apparatus including a process chamber 100 and a plurality of

vacuum pumps

1A and 1B for evacuating the process chamber 100. You may make it provide. The operator can accurately know the maintenance timing of the

vacuum pumps

1A and 1B attached to the process chamber 100 by a warning from the pump monitoring device 120.

In the above-described embodiment, when setting the threshold value α for determining whether or not there is an abnormality, the difference is set as α = 6σ using the standard deviation σ of MA−MB. You may set using an average value.

In the above-described embodiment, the case where two vacuum pumps are attached to the process chamber 100 has been described as an example, but the present invention can be applied to the case where three or more vacuum pumps are attached. Even when three or more vacuum pumps are installed, since each vacuum pump is used under the same conditions, any one of the plurality of vacuum pumps is abnormal (ie, excessive deposition of reaction products). Is detected, the pump monitoring device 120 warns that maintenance is required for all of the plurality of vacuum pumps attached to the process chamber 100.

The pump monitoring device 120 obtains motor current values from two arbitrary pumps from a plurality of vacuum pumps attached to the process chamber 100, and the difference | ΔM | between the two motor current values is | ΔM | It is determined whether> α. Such determination regarding any two units is performed for all of the plurality of vacuum pumps. For example, when five

vacuum pumps

1A, 1B, 1C, 1D, and 1E are attached to the process chamber 100, three types of (1A, 1B), (1C, 1D), and (1E, 1A) It is determined whether or not | ΔM |> α with respect to the combination. If | ΔM |> α for at least one of the three combinations, the maintenance warning is issued for all of the five vacuum pumps 1A to 1E.

The three combinations (1A, 1B), (1C, 1D), and (1E, 1A) include all of the

vacuum pumps

1A, 1B, 1C, 1D, and 1E attached to the process chamber 100. Therefore, the abnormality determination is performed for all the vacuum pumps 1A to 1E by performing the above-described abnormality detection processing for the three types of combinations.

-Second Embodiment-
In the first embodiment described above, the motor current values MA and MB are used as signals representing the rotation state of the pump rotor 14, but in the second embodiment, magnetism generated based on the displacement signal of the displacement sensor. A signal indicating the rotation state is calculated based on the bearing control amount. As shown in FIG. 5, the radial

magnetic bearings

17A, 17B, and 17C are provided with displacement sensors for detecting the flying position of the rotor shaft 15, respectively. Below, the case where the displacement signal of displacement sensor X2a, X2b, Y2a, Y2b which detects the floating position of a radial direction is used as a signal showing a rotation state is demonstrated.

As shown in FIG. 5, the radial magnetic bearing 17 A includes two pairs of electromagnets arranged so as to sandwich the rotor shaft 15. A pair of displacement sensors X2a and X2b are provided for one electromagnet pair arranged in the x-axis direction, and a pair of displacement sensors Y2a and Y2b are provided for the other electromagnet pair arranged in the y-axis direction. It has been.

FIG. 7 is a block diagram illustrating magnetic bearing control related to the displacement sensors X2a and X2b. The block diagram regarding the displacement sensors Y2a and Y2b is exactly the same as in the case of FIG. The displacement signals of the displacement sensors X2a and X2b change according to the size of the gap between the displacement sensors X2a and X2b and the rotor shaft 15. Displacement signals from the displacement sensors X2a and X2b are input to the differential amplifier 602. The differential amplifier 602 outputs a differential signal Vdif that is a difference value between them.

The differential signal Vdif is input to the PID control circuit 53. The PID control circuit 53 performs PID calculation on the current value to be passed through the electromagnet 37x so that the differential signal Vdif becomes zero, that is, the rotor shaft 15 is supported at the center of the displacement sensors X2a and X2b, and the magnetic It outputs to the current amplifier 55 as a bearing control amount. The current amplifier 55 supplies an electromagnet current corresponding to the input magnetic bearing control amount to the electromagnet 37x.

In the present embodiment, based on the magnetic bearing control amount output from the PID control circuit 53 to the current amplifier 55, an XY value that is a signal indicating the rotational state of the pump rotor 14 is calculated. Hereinafter, the magnetic bearing control amount in the x-axis direction is represented as PID-IX, and the magnetic bearing control amount in the y-axis direction is represented as PID-IY. The pump monitoring device 120 reads these magnetic bearing control amounts PID-IX and PID-IY from the

vacuum pumps

1A and 1B, respectively, and calculates the XY value represented by Expression (1).
XY = {(PID-IX) ² + (PID-IY) ² } ^1/2 (1)

The XY value represented by the equation (1) is introduced as an index representing the horizontal force applied to the pump rotor 14, that is, the deviation of the axial center of the pump rotor 14 from the target flying position. The greater the horizontal force, that is, the greater the deviation of the axial center of the pump rotor 14 from the target flying position, the greater the XY value. When the amount of accumulated reaction product increases and the cylindrical portion 14b and the screw stator 64 come into contact with each other and a force is applied to the pump rotor 14, the deviation of the shaft core, which is the rotational state of the pump rotor 14, increases, and the XY value also increases. Become.

FIG. 8 is a diagram illustrating an example of the XY value. FIG. 8 shows the XY values detected by the two

vacuum pumps

1A and 1B attached to the same process chamber. The pump state is almost the same as the case shown in FIG. In FIG. 8, the vertical axis represents the XY value, the horizontal axis represents time, the line SA indicated by a solid line indicates the XY value of the vacuum pump 1A, and the line SB indicated by a broken line indicates the XY value of the vacuum pump 1B.

The change pattern of the XY values SA and SB in each section C is the same pattern in any section C. However, the difference | ΔXY | between the XY value SA and the XY value SB at time t3 is larger than | ΔXY | at other times. Such an instantaneous increase of | ΔXY | is considered to be caused by contact between the cylindrical portion 14 b and the screw stator 64. Actually, when a momentary increase in the motor current value as indicated by reference symbol A in FIG. 3 occurs, a momentary increase in | ΔXY | as shown in FIG. 8 also occurs at the same time.

Since the pump rotor 14 is shaken even when a disturbance acts on the pump rotor 14 or when there is a sudden change in gas load, the magnetic bearing control amounts PID-IX and PID-IY suppress the fluctuation. fluctuate. Therefore, the XY value fluctuates to some extent even in a state where there is no contact between the cylindrical portion 14b and the screw stator 64.

In this embodiment, the pump monitoring device 120 calculates the XY values of the

vacuum pumps

1A and 1B, respectively. When the difference ΔXY between the two calculated XY values is larger than the predetermined threshold value | ΔXY |, either of the

vacuum pumps

1A and 1B is abnormal (that is, an excess of reaction products). Warn that a major deposit has occurred. That is, it warns that maintenance of the

vacuum pumps

1A and 1B is necessary. Note that the threshold α can be set in the same manner as in the first embodiment. For example, when the standard deviation of the difference ΔXY is σ, 6σ may be set as the threshold α.

FIG. 9 is a flowchart showing an example of the abnormality determination process in the second embodiment. In step S200, as in the case of the first embodiment, a threshold value α based on the XY values SA and SB in the initial state is set. In this case, the motor current values MA and MB in the first embodiment may be replaced with the XY values SA and SB, and the same processing as step S100 in FIG. 6 may be performed, and detailed description thereof is omitted here. The calculated threshold value α is stored in a storage unit (not shown) provided in the pump monitoring device 120.

Next, in step S210, the XY values SA and SB are read, and in step S220, the magnitude of the difference between the XY values | ΔXY | = | SA−SB | is calculated. In step S230, it is determined whether the magnitude relationship between | ΔXY | and the threshold value α is | ΔXY |> α. If it is determined in step S230 that | ΔXY |> α, the process proceeds to step S240, and a warning process similar to the warning process in step S140 of the first embodiment is executed.

On the other hand, if it is determined in step S230 that | ΔXY | ≦ α, the process returns to step S210, and the processing from step S210 to step S230 is executed again. The processing from step S210 to step S230 is repeatedly executed at predetermined time intervals until it is determined yes in step S230.

(C3) As described above, in the second embodiment, the pump rotor 14 is a signal representing the rotation state based on the magnetic bearing control amounts PID-IX and PID-IY when the pump rotor 14 is supported by magnetic levitation. A certain XY value was calculated. Then, the XY values SA and SB are calculated for the

vacuum pumps

1A and 1B, respectively, and the magnitude of the difference | ΔXY | is compared with the threshold value α, thereby causing an abnormality in either of the

vacuum pumps

1A and 1B. Estimate that.

The XY value represents the deviation of the axial center of the pump rotor 14 with respect to the target flying position. When the amount of accumulated reaction products increases and the cylindrical portion 14b and the screw stator 64 come into contact with each other, a force is applied to the pump rotor 14. The deviation of the shaft core, which is the rotational state of the pump rotor 14, increases, and the XY value also increases. Therefore, regarding the

vacuum pumps

1A and 1B, the magnitude of the difference between the XY values | ΔXY | is compared with the threshold value α, so that either of the

vacuum pumps

1A and 1B is abnormal (ie, excessive deposition of reaction products). ) Can be easily detected.

Note that it may be detected that an abnormality has occurred in either of the

vacuum pumps

1A and 1B by using both the difference XY value difference XY and the motor current value difference ΔM described above.

In the above description, when detecting contact between the pump rotor 14 and the screw stator 64, the displacement signals of the displacement sensors X2a, X2b, Y2a, Y2b close to the pump rotor 14 in the axial direction are used, but the displacement sensors X1a, You may use the displacement signal of X1b, Y1a, Y1b.

-Third embodiment-
FIG. 10 is a diagram for explaining the third embodiment, and is a block diagram showing the configuration of the

vacuum pumps

1A and 1B provided in the semiconductor manufacturing apparatus 10 as in FIG. In the first and second embodiments described above, the pump monitoring device 120 is provided in the main controller 110 of the semiconductor manufacturing apparatus 10. On the other hand, in the third embodiment, the pump monitoring device 120 is provided in the controller 12 for each of the

vacuum pumps

1A and 1B. Other configurations are the same as those shown in FIG.

The pump monitoring device 120 provided in the controller 12 of the vacuum pump 1A acquires a signal indicating the rotation state of the pump rotor 14 of the vacuum pump 1A, and at the same time, the pump rotor 14 of another vacuum pump 1B via the communication line 40. A signal indicating the rotation state is acquired from the vacuum pump 1B. Similarly, the pump monitoring device 120 provided in the controller 12 of the vacuum pump 1B obtains a signal indicating the rotation state of the pump rotor 14 of the vacuum pump 1B, and pumps of other vacuum pumps 1A via the communication line 40. A signal indicating the rotation state of the rotor 14 is acquired from the vacuum pump 1A.

The signal indicating the rotation state of the pump rotor 14 may be the motor current values MA and MB acquired from the motor control unit 23 described in the first embodiment, or the magnetic bearing described in the second embodiment. An XY value calculated from the magnetic bearing control amounts PID-IX and PID-IY acquired from the control unit 22 may be used. Regardless of which signal is used, each of the

vacuum pumps

1A, 1B detects that an abnormality (that is, excessive deposition of reaction products) has occurred in one of the

vacuum pumps

1A, 1B. .

The abnormality detection result detected in each of the

vacuum pumps

1A and 1B is transmitted to the main controller 110 via the communication line 40. If an abnormality detection result is input from at least one of

vacuum pumps

1A and 1B, main controller 110 displays a warning display informing that the maintenance time for

vacuum pumps

1A and 1B has come.

(C6) In this embodiment, as shown in FIG. 10, the pump monitoring device 120 is provided in the controller 12 of the vacuum pump 1A, and the communication port 21 which is the signal input unit of the controller 12 is connected to the other vacuum pump 1B. A motor current value MB, which is a signal representing the rotation state, is input. The pump monitoring device 120 compares the motor current value MA, which is a signal indicating the rotation state of the pump rotor 14 of the vacuum pump 1A, with the motor current value MB input from the communication port 21, that is, the difference ΔM = The pump abnormality is estimated by comparing the magnitude | ΔM | of the MA-MB with the threshold value α.

Thus, since each of the

vacuum pumps

1A and 1B performs pump abnormality estimation, the use of both estimation results increases the redundancy for abnormality detection, and the abnormality of the

vacuum pumps

1A and 1B can be reliably detected. it can.

-Fourth embodiment-
FIG. 11 is a diagram for explaining the fourth embodiment. In the fourth embodiment, the pump monitoring device 120 detects that an abnormality (that is, excessive deposition of reaction products) has occurred in the vacuum pumps attached to the process chambers of the plurality of semiconductor manufacturing apparatuses. To do. In the example shown in FIG. 11, the pump monitoring device 120 monitors the vacuum pumps 1A to 1F attached to the process chambers 100A to 100B of the three

semiconductor manufacturing apparatuses

10A, 10B, and 10C.

Each of the semiconductor manufacturing apparatuses 10A to 10C is provided with a wireless communication apparatus 140. The pump monitoring device 120 is also provided with a wireless communication device 200, and information can be exchanged between the communication device 140 and the communication device 200. The pump monitoring device 120 can acquire signals indicating the rotation states of the pump rotors of the vacuum pumps 1A to 1F from the respective semiconductor manufacturing devices 10A to 10C via the communication devices 140 and 200. Hereinafter, a case where the signal indicating the rotation state is a motor current value will be described as an example.

Even when the three semiconductor manufacturing apparatuses 10A to 10C are the same apparatus, if the latest maintenance timings of the vacuum pumps 1A to 1F provided in the semiconductor manufacturing apparatuses 10A to 10C are different, each semiconductor manufacturing apparatus The next maintenance time of the vacuum pump at 10A to 10C will be different. Therefore, the pump monitoring device 120 detects abnormality of the vacuum pump for each of the semiconductor manufacturing apparatuses 10A to 10C.

When determining abnormality of the

vacuum pumps

1A and 1B, motor current values MA and MB of the

vacuum pumps

1A and 1B are acquired from the semiconductor manufacturing apparatus 10A. The abnormality detection process based on the motor current values MA and MB is the same as the abnormality detection process shown in FIG. 6 of the first embodiment. That is, the arithmetic part 210 sets the threshold value α used for abnormality determination based on the motor current values MA and MB in the initial state. The threshold value α is stored in the storage unit 220. The calculation unit 210 acquires the motor current values MA and MB from the semiconductor manufacturing apparatus 10A at predetermined time intervals, and the magnitude of the difference between the motor current values MA and MB | ΔM | = | MA−MB | is | ΔM |> α. It is determined whether or not. If | ΔM |> α, it is determined that an abnormality has occurred in either of the

vacuum pumps

1A and 1B, and a warning display for prompting maintenance of the

vacuum pumps

1A and 1B is displayed on the display unit 230.

Regarding the vacuum pumps 1C, 1D and 1E, 1F of the

semiconductor manufacturing apparatuses

10B, 10C, the same abnormality determination processing as that of the

vacuum pumps

1A, 1B of the semiconductor manufacturing apparatus 10A is performed individually for each of the

semiconductor manufacturing apparatuses

10B, 10C.

(C4) In the fourth embodiment, the pump monitoring device 120 receives motor current values MA to MF from the vacuum pumps 1A to 1F provided to each of the one or more

semiconductor manufacturing devices

10A, 10B, and 10C. It is estimated that an abnormality has occurred in one of the two vacuum pumps provided in each of the

semiconductor manufacturing apparatuses

10A, 10B, and 10C.

By providing such a pump monitoring device 120, it is possible to individually detect the abnormality of the vacuum pumps provided to the plurality of

semiconductor manufacturing apparatuses

10A, 10B, and 10C.

In the example shown in FIG. 11, the communication apparatus 200 is a wireless system, but may be a wired system. By using a wireless system, remote collective management can be easily performed.

Although various embodiments have been described above, the present invention is not limited to these contents. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. A plurality of embodiments may be combined.

1A, 1B, 1C, 1D, 1E, 1F ... Vacuum pump, 10 ... Semiconductor manufacturing equipment, 11 ... Pump body, 12 ... Controller, 14 ... Pump rotor, 16 ... Motor, 17 ... Magnetic bearing, 17A, 17B ... Radial magnetism Bearing, 17C ... axial magnetic bearing, 21,44 ... communication port, 22 ... magnetic bearing controller, 23 ... motor controller, 100, 100A ... process chamber, 110 ... main controller, 120 ... pump monitoring device, MA, MB ... Motor current value, SA, SB ... XY value, X1a, X1b, Y1a, Y1b, X2a, X2b, Y2a, Y2b, z ... Displacement sensor

Claims

A pump monitoring device for detecting an abnormality of a plurality of vacuum pumps connected to the same chamber,
A pump monitoring apparatus that estimates that an abnormality has occurred in any of the plurality of vacuum pumps based on a result of comparing signals representing the rotation states of the pump rotors of the plurality of vacuum pumps.
The pump monitoring device according to claim 1,
The signal representing the rotational state is a motor current value of a motor that rotationally drives the pump rotor,
A pump monitoring device that estimates that an abnormality has occurred in any of the plurality of vacuum pumps based on a difference in the motor current values of the vacuum pumps different from each other.
The pump monitoring device according to claim 1,
The pump rotor is magnetically levitated and supported by a magnetic bearing,
The pump monitoring device, wherein the signal representing the rotation state is calculated based on a magnetic bearing control amount of the magnetic bearing.
The pump monitoring device according to claim 1,
From one or more vacuum processing apparatuses including a plurality of vacuum pumps for evacuating the chamber, an input unit to which a signal indicating the rotation state of the plurality of vacuum pumps is input,
A pump monitoring apparatus that estimates that an abnormality has occurred in any of the plurality of vacuum pumps for each of the vacuum processing apparatuses.
A chamber;
A plurality of vacuum pumps for evacuating the chamber;
A vacuum processing apparatus comprising: the pump monitoring apparatus according to claim 1.
A pump monitoring device according to claim 1;
A pump rotor driven to rotate by a motor;
An input unit to which a signal representing a rotation state from another vacuum pump is input;
The said pump monitoring apparatus is a vacuum pump which compares the signal showing the rotation state of the said pump rotor with the signal showing the rotation state input from the said input part, and estimates pump abnormality.