Vacuum Pump System

Abstract

Accurately estimate the deposition state of sediments. [Solution] The vacuum pump is equipped with a vacuum gauge (110) that detects the gas pressure in the gas flow path through which gas drawn in from the intake port flows to the exhaust port (65), and an estimation unit (24) that estimates the state of deposits accumulated in the gas flow path based on the gas pressure detected by the vacuum gauge (110).

Description

[Technical Field]

[0001] The present invention relates to a vacuum pump system. [Background technology]

[0002] 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, and a vacuum pump such as a turbomolecular pump is used to evacuate the gas inside the process chamber and maintain the high vacuum.When evacuating gas inside a process chamber such as dry etching or CVD, reaction products accumulate inside the pump as the gas is evacuated.

[0003] Regarding the deposition of such reaction products, a method for detecting products deposited inside a pump is disclosed in Patent Document 1. The deposit detection method disclosed in Patent Document 1 measures the current value of the motor that rotates and drives the rotating body of the pump, and issues a warning if the amount of change in the measured value from the initial value of the motor current is equal to or greater than a predetermined value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent No. 5767632 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in reality, the flow rate of the exhaust gas varies greatly even within a single process, and the current value of the motor that rotates the rotor also varies greatly in accordance with the fluctuation in the gas flow rate, which makes misjudgment inevitable. [Means for solving the problem]

[0006] The vacuum pump system according to the present invention comprises a vacuum pump having an intake port, an exhaust port, and a pressure detection unit that detects the gas pressure in a gas flow path through which gas drawn in from the intake port flows to the exhaust port, and a computing device that calculates the state of deposits accumulated in the gas flow path based on the gas pressure detected by the pressure detection unit. [Effects of the Invention]

[0007] According to the present invention, the accumulation state of deposits accumulated in the exhaust flow passage can be estimated with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a turbomolecular pump according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of a deposit estimation device used in a turbomolecular pump according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing the configuration of a turbomolecular pump according to the second embodiment. [Figure 4] FIG. 4 is a diagram showing the configuration of a turbomolecular pump according to the third embodiment. [Figure 5] FIG. 5 is a diagram showing the configuration of a turbomolecular pump according to the fourth embodiment. [Figure 6] FIG. 6 is a diagram showing the configuration of a turbomolecular pump according to the fifth embodiment. [Figure 7] FIG. 7 is a diagram showing the configuration of a vacuum pump system according to the fifth modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. -First embodiment- FIG. 1 shows a vacuum pump 1 in a first embodiment, and FIG. 2 shows a controller 12 that controls the operation of the vacuum pump 1. The vacuum pump 1 is attached to a process chamber (not shown) via a pressure regulating valve (not shown). The vacuum pump 1 and the pressure regulating valve are controlled by a controller 12 (see FIG. 2), which regulates and controls the air pressure in the process chamber. That is, the controller 12 controls the pressure regulating valve, the pump motor, the temperature, and the magnetic levitation. The controller 12 also performs a deposit estimation calculation. The deposit estimation calculation estimates the state of deposits that have accumulated in the gas flow path of the vacuum pump 1 based on the gas pressure in the flow path. The controller 12 is described below with reference to FIG.

[0010] The vacuum pump 1 shown in FIG. 1 is a magnetic bearing turbomolecular pump equipped with a turbopump unit TP with turbine blades and a Holweck pump unit HP with spiral grooves as its exhaust function units. The turbopump unit TP and Holweck pump unit HP are housed in a pump casing 11, also known as a housing. The pump casing 11 includes a base 60 and a casing 61 stacked on top of the base 60. An exhaust port 65 is provided on the side of the base 60, and an intake port 61a is provided on the top surface of the casing 61. The intake port 61a is connected to a vacuum chamber (process chamber) via a pressure regulation valve (not shown), and an auxiliary pump (not shown) called a back pump is connected to the exhaust port 65. A pressure regulation valve may be provided instead of the auxiliary pump. The turbomolecular pump 1 evacuates the process chamber, and the pressure is regulated to a predetermined value by the pressure regulation valve.

[0011] The present invention is not limited to vacuum pumps having a turbo pump section TP and a Holweck pump section HP in the exhaust function section, but can also be applied to vacuum pumps having only turbine blades, vacuum pumps having only drag pumps such as Siegbahn pumps and Holweck pumps, and vacuum pumps that combine these. The Holweck pump section HP is also called the screw groove pump section.

[0012] The pump housing 11 is provided with a rotating body R. The rotating body R includes a pump rotor 14 and a rotor shaft 15 fastened to the pump rotor 14. The rotor shaft 15 is rotated by a pump motor 16. The pump rotor 14 has multiple stages of rotor blades 14a formed on the upstream side and a cylindrical portion 14b forming a threaded pump formed on the downstream side. Corresponding to these, multiple fixed-vane stators 62 and a cylindrical screw stator 64 are provided on the fixed side. There are types in which a thread is formed on the inner circumferential surface of the screw stator 64, and types in which a thread is formed on the outer circumferential surface of the cylindrical portion 14b. Each fixed-vane stator 62 is mounted on a base 60 via a spacer ring 63. The upstream side of the pump housing 11 is the turbo pump section TP, and the downstream side is the Holweck pump section HP.

[0013] Rotor shaft 15 is magnetically levitated and supported by radial magnetic bearings 17A, 17B and axial magnetic bearing 17C provided on base 60, and is rotationally driven by motor 16. Each of magnetic bearings 17A to 17C is equipped with an electromagnet and a displacement sensor, and the displacement sensor detects the levitated position of rotor shaft 15. The rotation speed of rotor shaft 15 is detected by rotation speed sensor 18. When magnetic bearings 17A to 17C are not operating, rotor shaft 15 is supported by emergency mechanical bearings 66a, 66b. Magnetic bearings 17A to 17C are indicated by the representative reference numeral 17. When the rotor shaft 15 to which the pump rotor 14 is fastened is rotated at high speed by the motor 16, gas molecules on the intake port 61a side are exhausted to the exhaust port 65 side.

[0014] The base 60 is provided with a heater 19 and refrigerant piping 20 through which a refrigerant such as cooling water flows. A refrigerant supply piping (not shown) is connected to the refrigerant piping 20, and the flow rate of the refrigerant to the refrigerant piping 20 can be adjusted by controlling the opening and closing of an electromagnetic on-off valve installed in the refrigerant supply piping. When exhausting gas that is prone to deposit reaction products, the heater 19 is turned on and off and the flow rate of the refrigerant flowing through the refrigerant piping 20 is turned on and off to prevent product deposition in the thread groove pump portion and the downstream rotor 14a, thereby adjusting the base temperature to a predetermined temperature, for example, near the screw stator fixing portion.

[0015] (Controller 12) The controller 12 will now be described with reference to FIG. As shown in Fig. 1, the turbomolecular pump 1 includes a motor 16, a magnetic bearing (MB) 17, and a rotation speed sensor 18. The controller 12 includes a processing unit such as a CPU or FPGA. The processing unit functions as a motor control unit 23, a magnetic bearing control unit (MB control unit) 22, and a deposit estimation unit 24. A storage unit 25 stores a program for driving and controlling the pump, a program for estimating the deposition state of deposits (hereinafter referred to as the deposit estimation program), and the like. As will be described later, a table showing the deposition state of deposits versus gas pressure is created and stored in advance in the storage unit 25.

[0016] Motor control unit 23 estimates the rotation speed of rotor shaft 15 based on the rotation signal detected by rotation speed sensor 18, and controls motor 16 to a predetermined target rotation speed based on the estimated rotation speed. As the gas flow rate increases, the load on pump rotor 14 increases, causing the rotation speed of motor 16 to decrease. Motor control unit 23 maintains the predetermined target rotation speed (rated rotation speed) by controlling the motor current so that the difference between the rotation speed detected by rotation speed sensor 18 and the predetermined target rotation speed becomes zero. The magnetic bearing 17 includes a bearing electromagnet and a displacement sensor for detecting the levitation position of the rotor shaft 15 . The vacuum gauge 110 is a pressure gauge that detects the gas pressure in the gas flow path 71 in the boundary region between the turbo pump section TP and the Holweck pump section HP, as will be described later.

[0017] The deposit estimation unit 24 is a computing device that executes a deposit estimation program stored in the memory unit 25 to estimate the state of deposits accumulated in the gas flow path of the turbomolecular pump 1 based on the gas pressure P110 detected by the vacuum gauge 110. A state in which the turbomolecular pump 1 cannot operate normally due to excessive deposits is defined as a pump abnormality state. To prevent this pump abnormality state from occurring, the occurrence of a pump abnormality is predicted at a time well before the time when the pump abnormality state actually occurs. Here, however, the time when a pump abnormality is predicted is referred to as pump abnormality detection.

[0018] Generally, the turbomolecular pump 1 rotates continuously at a constant rotation speed, and the opening of the pressure regulating valve is controlled according to the target pressure of the process chamber. The opening of the pressure regulating valve can be controlled in various ways, such as by the controller 12 or by a separately provided main controller.

[0019] (Detection of sediment conditions) As described above, the turbomolecular pump 1 of the first embodiment is provided with a vacuum gauge 110 that detects the gas pressure in the boundary region between the turbo pump section TP and the Holweck pump section HP, i.e., in the flow path 71 that communicates from the turbo pump section TP to the Holweck pump section HP. That is, a gas pressure measurement port 60a is provided on the outer circumferential surface of the base 60, and a gas pressure measurement passage (hereinafter referred to as a measurement passage) 67 is provided between this gas pressure measurement port 60a and the flow path 71 in the boundary region.

[0020] The amount of deposits is estimated or predicted based on the pressure P110 detected by the vacuum gauge 110 by a deposit estimation program implemented in the memory unit 25 of the controller 12. In the first embodiment, the amount of deposits can be estimated, for example, as follows. A table showing the deposition state of deposits versus gas pressure (hereinafter referred to as the gas pressure-deposition state table) is created and stored in advance in the memory unit 25 of the controller 12. The gas pressure-deposition state table is referenced using the detected gas pressure P110 to read out the deposition state of deposits. If the gas pressure indicating the deposition state is equal to or greater than a predetermined threshold, a warning is issued that the operation of the turbomolecular pump 1 is not normal, i.e., an abnormality has occurred. The threshold in this case is an abnormality determination threshold. Even if the gas pressure P110 is smaller than the abnormality determination threshold, it may become equal to or greater than the abnormality determination threshold in the near future, for example, one hour from now. Such a gas pressure may be set as the abnormality determination threshold. In other words, multiple abnormality determination thresholds may be set to notify and warn the user.

[0021] As described above, the vacuum pump of the first embodiment has the following advantages. Fluctuations in gas pressure due to an increase in deposits are larger than fluctuations in motor current, allowing for early detection of changes in the state of deposits. Accurate detection of an increase in deposits due to fluctuations in motor current requires a pressure rise of, for example, approximately 150 Pa. In this regard, in an embodiment in which the state of deposits is detected based on pressure fluctuations in the boundary region 71 between the turbine pump section TP and the Holweck pump section HP, accurate detection is possible with the vacuum gauge 110 within a range of, for example, approximately 20 Pa to 50 Pa. Incidentally, when the pressure fluctuates between approximately 20 Pa and 50 Pa, the motor current fluctuates within a range of 0.1 A to 0.5 A, but accurate detection is difficult when noise superimposed on the motor current is taken into account.

[0022] -Second embodiment- The turbomolecular pump 1 of the second embodiment is a vacuum pump that not only detects the pressure of the gas flowing through the flow path 71 in the boundary region between the turbo pump section TP and the Holweck pump section HP, but also detects the gas pressure on the inlet side of the turbo pump section TP, making it possible to monitor the deposition state of deposits.

[0023] With reference to FIG. 3, differences from the first embodiment will be mainly described below. The turbomolecular pump 1 of the second embodiment is provided with a vacuum gauge 120 that measures the gas pressure on the inlet side of the turbopump section TP. The intake port 61a has a flow path 72 into which exhaust gas from the process chamber flows in via a pressure adjustment valve (not shown), and the vacuum gauge 120 detects the gas pressure of this flow path 72. That is, a gas pressure measurement port 61b is provided on the outer surface of the casing 61, and a gas pressure measurement passage (hereinafter referred to as the measurement passage) 61c is provided between this gas pressure measurement port 61b and the inlet side gas flow path 72. Figure 3 schematically explains the installation position of the vacuum gauge 120, and the installation position of the gas pressure measurement port 61b is appropriately set depending on the specifications of the turbomolecular pump 1.

[0024] The amount of deposits is estimated or predicted based on the pressure P110 detected by the vacuum gauge 110 and the pressure P120 detected by the vacuum gauge 120 by a deposit estimation program implemented in the memory unit 25 of the controller 12. In the second embodiment, the amount of deposits can be estimated, for example, as follows.

[0025] In the vacuum pump of the second embodiment, the gas pressure P120 at the intake port 61a and the gas pressure P110 in the flow path 71 in the boundary region between the turbo pump section TP and the Holweck pump section HP are detected by vacuum gauges 110 and 120, respectively. The difference ΔP1 between the gas pressures P110 and P120 indicates the pressure loss in the gas flow path between the gas inlet 72 and the gas outlet 71 of the turbo pump section TP. Therefore, the difference ΔP1 immediately after starting use of the turbo molecular pump 1 is measured and stored as a reference value, and the state of deposits can be detected by the deviation from this difference ΔP1.

[0026] A table showing the deposition state of deposits versus the difference ΔP1 is created and stored in advance in the memory unit 25 of the controller 12. The table is referenced using the difference ΔP1 between the detected gas pressures P110 and P120 to read out the deposition state of deposits. If the differential pressure ΔP1 is equal to or greater than a predetermined threshold, a warning is issued that the operation of the turbomolecular pump 1 is not normal, i.e., an abnormality has occurred. The threshold in this case is an abnormality determination threshold. Even if the gas pressure differential ΔP1 is smaller than the abnormality determination threshold, it may become equal to or greater than the abnormality determination threshold in the near future, for example, one hour from now. Such a gas pressure may be set as the abnormality determination threshold. In other words, multiple abnormality determination thresholds may be set to notify and warn the user.

[0027] As described above, the vacuum pump of the second embodiment has the following advantages. In the first embodiment, which detects the deposition state of deposits based solely on fluctuations in the outlet pressure of the turbo pump unit TP, the deposition state cannot be accurately detected when multiple target pressures are set within the process chamber. In contrast, in the second embodiment, the difference ΔP1 between pressures P110 and P120 is used, so that the pressure loss within the turbo pump unit TP can be accurately detected even when the pressure at the intake port 61a of the turbo molecular pump 1 varies. As a result, highly accurate deposit detection is possible even when the pressure target value varies depending on the processing content within the process chamber, i.e., regardless of the processing recipe performed in the process chamber.

[0028] -Third embodiment- The turbomolecular pump 1 of the third embodiment is a vacuum pump that is capable of detecting the gas pressure flowing through the flow path 71 in the boundary region between the turbo pump section TP and the Holweck pump section HP, as well as the gas pressure on the outlet side of the Holweck pump section HP, thereby making it possible to monitor the deposition state of deposits.

[0029] With reference to FIG. 4, differences from the first embodiment will be mainly described below. The turbomolecular pump 1 of the third embodiment is provided with a vacuum gauge 130 that measures the gas pressure on the outlet side of the Holweck pump section HP. A gas pressure measurement port 60b is provided on the outer surface of the base 60, and a gas pressure measurement passage (hereinafter referred to as the measurement passage) 68 is provided between this gas pressure measurement port 60b and the outlet side gas flow path 73 of the Holweck pump section HP. Figure 4 illustrates a schematic diagram of the attachment position of the vacuum gauge 130, and the installation position of the gas pressure measurement port 60b is appropriately set depending on the specifications of the turbomolecular pump 1.

[0030] The amount of deposits is estimated or predicted based on the pressure P110 detected by the vacuum gauge 110 and the pressure P130 detected by the vacuum gauge 130 by a deposit estimation program implemented in the memory unit 25 of the controller 12. In the third embodiment, the amount of deposits can be estimated, for example, as follows.

[0031] In the vacuum pump of the third embodiment, the gas pressure P110 in the flow path 71 in the boundary region between the turbo pump section TP and the Holweck pump section HP, and the gas pressure P130 in the flow path 73 near the outlet side of the Holweck pump section HP are detected by vacuum gauges 110 and 130, respectively. The difference ΔP2 between the gas pressures P110 and P130 is the gas pressure between the gas inlet and the gas outlet of the Holweck pump section HP. This indicates the pressure loss in the flow path. Therefore, the difference ΔP2 immediately after starting use of the turbo molecular pump 1 is measured and stored as a reference value, and the state of deposits can be detected by the deviation from this difference ΔP2.

[0032] A table showing the deposition state of deposits relative to the difference ΔP2 is created and stored in advance in the memory unit 25 of the controller 12. The table is referenced using the difference ΔP2 between the detected gas pressures P110 and P130 to read out the deposition state of deposits. If the deposition state is equal to or greater than a predetermined threshold, a warning is issued that the operation of the turbomolecular pump 1 is not normal, i.e., an abnormality has occurred. The threshold in this case is an abnormality determination threshold. Even if the gas pressure difference ΔP2 is smaller than the abnormality determination threshold, it may become equal to or greater than the abnormality determination threshold in the near future, for example, one hour from now. Such a gas pressure may be set as the abnormality determination threshold. In other words, multiple abnormality determination thresholds may be set to notify and warn the user.

[0033] As described above, the vacuum pump of the third embodiment has the following advantages. In the second embodiment, in which the deposition state of deposits is estimated from the pressure difference ΔP1 between the inlet and outlet pressures of the turbo pump section TP, it is not possible to estimate the deposition state of deposits adhering to the Holweck pump section HP. In this regard, in the third embodiment, the difference ΔP2 between the pressure P110 and the pressure P130 is used, so the deposition state of deposits adhering to the Holweck pump section HP can be estimated. This allows accurate estimation of the pressure loss in the Holweck pump HP, and as a result, the deposition state of deposits adhering to the Holweck pump HP can be estimated.

[0034] -Fourth embodiment- The fourth embodiment will be described with reference to FIG. The turbomolecular pump 1 of the fourth embodiment is equipped with a vacuum gauge 120 that detects the gas pressure (inlet pressure of the turbo pump section TP) P120 at the intake port 61a of the turbomolecular pump 1, a vacuum gauge 110 that detects the outlet pressure (inlet pressure of the Holweck pump section HP) P110 of the turbopump section TP, and a vacuum gauge 130 that detects the outlet pressure P130 of the Holweck pump section HP.

[0035] The vacuum pump of the fourth embodiment has the following advantages. Based on the gas pressures at three locations in the exhaust flow path, the state of deposits in the turbo pump section TP and the state of deposits in the Holweck pump section HP can be detected. In the second embodiment, in which the deposition state of deposits is estimated from the pressure difference ΔP1 between the inlet and outlet pressures of the turbo pump unit TP, it is not possible to estimate the deposition state of deposits adhering to the Holweck pump unit HP. Furthermore, in the third embodiment, in which the deposition state of deposits is estimated from the pressure difference ΔP2 between the inlet and outlet pressures of the Holweck pump unit HP, it is not possible to estimate the deposition state of deposits adhering to the turbo pump unit TP. In contrast, in the fourth embodiment, it is possible to estimate the deposition state of deposits in the turbo pump unit TP from the pressure difference ΔP1 between the inlet and outlet pressures of the turbo pump unit TP, and it is possible to estimate the deposition state of deposits in the Holweck pump unit HP from the pressure difference ΔP2 between the inlet and outlet pressures of the Holweck pump unit HP.

[0036] -Fifth embodiment- The fifth embodiment is an example in which the present invention is applied to a vacuum pump apparatus equipped with a low-pressure side pressure regulating valve provided on the inlet side of a turbomolecular pump and a high-pressure side pressure regulating valve provided on the outlet side. The vacuum pump apparatus of the fifth embodiment monitors the deposition state of deposits by measuring the gas pressure on the gas discharge side of the low-pressure side pressure regulating valve and the gas pressure on the gas inlet side of the high-pressure side pressure regulating valve. The difference from the first to fourth embodiments is that the deposition state of deposits is monitored by gas pressure in a vacuum pump apparatus equipped with a low-pressure side pressure regulating valve and a high-pressure side pressure regulating valve, rather than in a vacuum pump alone. The differences from the second embodiment will be mainly explained below.

[0037] 6, the turbomolecular pump 1 has an intake port 61a connected to a process chamber 90 via a low-pressure-side pressure regulating valve 80. The intake port of the low-pressure-side pressure regulating valve 80 is connected to the process chamber 90, and the low-pressure-side pressure regulating valve 80 regulates the pressure of the gas flowing into the turbomolecular pump 1. A high-pressure-side pressure regulating valve 95 is provided at the exhaust port 65 of the turbomolecular pump 1, and regulates the gas exhaust pressure.

[0038] The vacuum pump apparatus of the fifth embodiment is provided with a vacuum gauge 140 that detects the pressure of gas flowing out of the valve element of the low-pressure side pressure adjustment valve 80. That is, the vacuum gauge 140 detects the gas pressure in the upstream flow path 74 where the gas flowing out of the low-pressure side pressure adjustment valve 80 flows into the intake port 61a. Specifically, a gas pressure measurement port 81a is provided on the outer surface of the outlet-side housing 81 of the low-pressure side pressure adjustment valve 80, and the vacuum gauge 140 is provided to the gas pressure measurement port 81a via a conduit 82. The vacuum pump apparatus of the fifth embodiment is also provided with a vacuum gauge 150 that detects the gas pressure at the gas inlet of the high-pressure side pressure adjustment valve 95. That is, the vacuum gauge 150 detects the gas pressure in the conduit 96 through which the exhaust gas flowing out from the exhaust port 65 of the turbomolecular pump 1 flows into the high-pressure side pressure adjustment valve 95.

[0039] The amount of deposits is estimated or predicted based on the pressure P140 detected by the vacuum gauge 140 and the pressure P150 detected by the vacuum gauge 150 by a deposit estimation program implemented in the memory unit 25 of the controller 12. In the fifth embodiment, the amount of deposits can be estimated, for example, as follows.

[0040] As described above, in the vacuum pump of the fifth embodiment, the pressure P140 downstream of the valve element of the low-pressure-side pressure regulation valve 80 and the gas pressure P150 at the gas inlet of the high-pressure-side pressure regulation valve 95 are detected by the vacuum gauges 140 and 150, respectively. The difference ΔP3 between the gas pressures P140 and P150 indicates the pressure loss in the gas flow path from the gas inlet side of the turbo pump section TP to the gas outlet side of the turbomolecular pump 1. Therefore, the difference ΔP3 immediately after starting use of the turbomolecular pump 1 is measured and stored as a reference value, and the state of deposits can be detected by the deviation from this difference ΔP3.

[0041] As described above, the vacuum pump of the fifth embodiment has the following advantages. In the first embodiment, which detects the deposition state of deposits based solely on fluctuations in the outlet pressure of the turbo pump unit TP, the deposition state cannot be accurately detected when multiple target pressures are set in the process chamber (when the recipe is switched). In contrast, in the fifth embodiment, the difference ΔP3 between P140 and P150 is used, so that the pressure loss in the turbo pump unit TP can be accurately detected even when the pressure at the intake port 61 a of the turbo molecular pump 1, which correlates with the target pressure in the process chamber, differs. Therefore, highly accurate deposit estimation processing is possible even when the pressure at the intake port 61 a of the turbo molecular pump 1 is controlled by the pressure regulating valve 80 according to the processing content (recipe) in the process chamber.

[0042] The following modifications are also within the scope of the present invention and can be combined with the above-described embodiment. In the following modifications, parts and the like having the same structure and function as those in the above-described embodiment will be referred to by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0043] (Variation 1) In the second embodiment, the deposition state of the deposits is calculated by comparing the pressure difference ΔP1 between the intake pressure P120 and the outlet pressure P110 of the turbo pump unit TP with a predetermined abnormality determination threshold. Generally, various processing contents (recipes) are performed in the process chamber, and the abnormality determination threshold can be set for each recipe. Since the target pressure in the process chamber differs depending on the recipe, the evaluation of the deposition state based on the difference between the intake port pressure P120 and the outlet pressure P110 differs for each recipe. Therefore, in the first modification, the abnormality determination threshold for the deposition state with respect to the pressure difference ΔP1 is set for each recipe. According to the first modification, even if the target pressure in the process chamber is changed by switching the recipe, the deposition state of the deposition section can be estimated with high accuracy.

[0044] (Variation 2) In the second to fourth embodiments, the deposition state of the deposit is estimated from the magnitude of the differences ΔP1 to ΔP3 between the gas pressures at two locations. In the second modification, the deposition state is estimated from the time change of each of the gas pressures at two locations. For example, the following three examples are given. i) The state of deposits in the turbo pump section TP may be estimated based on the time-dependent changes in the pressure P120 on the inlet side and the pressure P110 on the outlet side of the turbo pump section TP. ii) The state of deposits in the Holweck pump section HP may be estimated based on the time-dependent changes in the pressure P110 on the inlet side and the pressure P130 on the outlet side of the Holweck pump section HP. iii) The accumulation state of deposits adhering to the flow paths of the turbomolecular pump 1 may be estimated based on the time changes of the pressure P140 on the outlet side of the low-pressure side pressure regulating valve 80 and the pressure P150 on the inlet side of the high-pressure side pressure regulating valve 95. According to the second modification, the deposition state can be estimated with high accuracy by using the time change in gas pressure at two locations.

[0045] (Variation 3) In the second to fifth embodiments, the deposition state is determined based on the magnitude of the difference ΔP1 to P3 between the gas pressures at two locations. In the third modification, the deposition state is determined based on the time change of the difference ΔP1 to P3 between the gas pressures at two locations. For example, the following three examples are given. i) The state of deposits in the turbo pump section TP may be estimated based on the change over time of the difference ΔP1 between the pressure P120 on the inlet side of the turbo pump section TP and the pressure P110 on the outlet side thereof. ii) The state of deposits in the Holweck pump section HP may be estimated based on the time change in the difference ΔP2 between the pressure P110 on the inlet side and the pressure P130 on the outlet side of the Holweck pump section HP. iii) The state of deposits in the Holweck pump section HP may be estimated based on the time change in the difference ΔP3 between the pressure P140 on the outlet side of the low-pressure side pressure regulating valve and the pressure P150 on the inlet side of the high-pressure side pressure regulating valve. According to Modification 3, the deposition state can be estimated more accurately by using the time change in the difference in gas pressure between two locations. Since the difference in pressure between two locations represents the pressure loss, accurate estimation is possible by using the time change in pressure loss.

[0046] (Variation 4) The vacuum pumps and vacuum pump devices of the first to fifth embodiments and modifications 1 to 3 estimate whether an operational abnormality has occurred. Modification 4 predicts that an operational abnormality will occur in the future. For example, a prediction is made by comparing the time change of gas pressure collected in the past with the time change of gas pressure collected currently. For example, if the time change characteristics of the gas pressure that reached the abnormality judgment threshold in the past show a similar trend, a future operational abnormality can be predicted. As another example, the time-varying characteristics of the difference in gas pressure at multiple locations, such as upstream and downstream of the gas flow path, can be used to make predictions by comparing the differential time characteristics collected in the past with the differential time characteristics currently being collected. According to the fourth modification, it is possible to predict that an increase in the amount of deposits will cause an abnormal operation, and to carry out appropriate maintenance before the operation is interrupted.

[0047] In each of the above embodiments and Modifications 1 to 4, the turbomolecular pump controller 12 is provided with a deposit estimation unit 24, which estimates the deposition state based on a deposit estimation program and a gas pressure-deposition state table stored in a memory unit 25. In other words, the vacuum pump 1 can also be said to be a vacuum pump system that is configured with a pump main body having a turbo pump unit TP and a Holweck pump unit HP, a vacuum gauge 110, a deposit estimation unit 24, and a memory unit 25 that implements the deposit estimation program and the gas pressure-deposition state table. Instead of estimating the deposition state in the controller, which is the control section of the vacuum pump, as in the above embodiments and modifications 1 to 4, the deposition state estimation calculation may be performed in a processing device separate from the vacuum pump.

[0048] (Variation 5) In each of the above embodiments and Modifications 1 to 4, the deposit estimation unit 24 is provided in the controller 12 of the turbomolecular pump, and the deposit estimation unit 24 estimates the deposition state based on a deposit estimation program and a gas pressure-deposition state table stored in the memory unit 25. However, the following description will be made with reference to Fig. 7, which is a diagram illustrating a vacuum pump system 1B according to Modification 5. Modification 5 estimates the deposits by an external server instead of by the vacuum pump.

[0049] The vacuum pump system 1B includes a turbomolecular pump 1A and an external server 200 connected to the turbomolecular pump 1A via a network 300. The network 300 is a local network or a public network such as the Internet. The turbomolecular pump 1A includes a pump body having an intake port 61a, an exhaust port 65, a turbo pump section TP, and a Holweck pump section HP (not shown in FIG. 1), a vacuum gauge 110 provided in a gas flow path that exhausts gas taken in through the intake port 61a from the exhaust port 65, a MB control unit 22, a motor control unit 23, and a communication interface (communication I / F) 400. The pressure value measured by the vacuum gauge 110 is transmitted to the external server 200 via the network 300. The turbo molecular pump 1A is not provided with the deposit estimation unit 24 and the storage unit 25 for the deposit estimation program and gas pressure-deposition state table in the first to fifth embodiments.

[0050] The external server 200 includes a communication I / F 201 connected to the network 300, a deposit estimation unit 202 that calculates the deposit state based on the received pressure value, and a memory unit 203 that stores a deposit estimation program and a gas pressure-deposition state table. The pump control program is stored in a memory unit (not shown) of the turbomolecular pump 1A. The external server 200 is an arithmetic processing device configured with processing devices such as a CPU, FPGA, etc.

[0051] The deposit estimation unit 202 of the external server 200 uses the pressure value transmitted from the turbomolecular pump 1A to estimate the deposition state by referring to the gas pressure-deposition state table stored in the storage unit 203. The vacuum pump system of the fifth modification also provides the same effects as those described above. The vacuum pump system 1B of the fifth modification can also be applied to the second to fifth embodiments and the first to fourth modifications.

[0052] The vacuum pumps of the above-described embodiments and modifications have the following advantages. (1) In an embodiment according to the first aspect, the vacuum pump system includes a pressure detection unit that detects the gas pressure of an intake port, an exhaust port, and a gas flow path through which gas drawn in from the intake port flows to the exhaust port, and a computing device that calculates the state of deposits accumulated in the gas flow path based on the gas pressure detected by the pressure detection unit. This allows the deposition state of deposits to be estimated with higher accuracy than when the deposition state of deposits is estimated based on the motor current.

[0053] (2) In an embodiment of the second aspect, in the vacuum pump system of the first aspect, the pressure detection unit includes a plurality of pressure detection elements provided at different locations to detect gas pressure at multiple locations in the gas flow path, and the arithmetic device calculates the state of deposits accumulated in the gas flow path based on the gas pressure detected by the plurality of pressure detection elements. This allows for more accurate estimation of the deposition state than when estimating it from the pressure at one location, and also makes it possible to identify locations where the deposition state has deteriorated.

[0054] (3) In an embodiment according to the third aspect, in the vacuum pump system of the second aspect, the computing device calculates the state of deposits accumulated in the gas flow path based on the time changes of each of the gas pressures detected by the multiple pressure detection elements. This allows for more accurate estimation of the deposition state than when estimating it from the pressure at one location, and also makes it possible to identify locations where the deposition state has deteriorated. (4) In an embodiment according to the fourth aspect, in the vacuum pump system of the second aspect, the computing device calculates the state of deposits accumulated in the gas flow path based on the difference in gas pressure detected by the multiple pressure detection elements. For example, the pressure difference between two locations, upstream and downstream, correlates with pressure loss, allowing for accurate estimation of the deposition state. (5) In an embodiment according to the fifth aspect, in the vacuum pump system of the second aspect, the computing device calculates the state of deposits accumulated in the gas flow path based on the change over time in the difference in gas pressure detected by the multiple pressure detection elements. For example, the pressure difference between two locations, upstream and downstream, correlates with pressure loss, allowing for accurate estimation of the deposition state. Furthermore, using the time change in the difference can prevent erroneous estimation. (6) In an embodiment according to the sixth aspect, in the vacuum pump system according to the first to fifth aspects, the arithmetic device has a memory unit that stores the relationship between pressure information regarding the detected gas pressure and the deposition state of the deposits, and the arithmetic device calculates the deposition state based on the relationship between the pressure information stored in the memory unit and the deposition state of the deposits and the gas pressure detected by the pressure detection unit. This simplifies the calculation process for estimating the deposits and reduces the processing time. (7) In an embodiment according to the seventh aspect, in the vacuum pump system of the sixth aspect, the memory unit stores the relationship between pressure information regarding the detected gas pressure and the deposition state of the deposit for each recipe, which is the processing content performed in the process chamber to which the vacuum pump is connected, and the calculation device calculates the deposition state based on the recipe and the pressure information regarding the gas pressure. This makes it possible to accurately estimate the deposition state of the deposition section even if the target pressure in the process chamber is changed by switching the recipe.

[0055] (8) In an embodiment according to the eighth aspect, in the vacuum pump systems of the first to seventh aspects, the vacuum pump has a turbo pump unit and / or a thread groove pump unit, the pressure detection unit detects the gas pressure of the turbo pump unit and / or the thread groove pump unit, and the calculation device calculates the state of the deposit based on the gas pressure detected in the gas flow path of the turbo pump unit and / or the thread groove pump unit. This prevents the buildup of deposits in various vacuum pumps such as turbomolecular pumps and drag pumps. The condition can be estimated. (9) In an embodiment according to a ninth aspect, in the vacuum pump system of any one of the first to eighth aspects, the vacuum pump has at least the turbo pump unit, and the pressure detection unit includes a first pressure detection unit that detects the gas pressure in the upstream flow path of the turbo pump unit and a second pressure detection unit that detects the gas pressure in the downstream flow path of the turbo pump unit, and the calculation device calculates the state of the deposit based on the gas pressure detected by the first pressure detection unit and the second pressure detection unit. This makes it possible to estimate the state of deposits in the turbo pump section. (10) In an embodiment according to the tenth aspect, in the vacuum pump system according to the eighth aspect, the vacuum pump has at least the grooved pump section, and includes a first pressure detection section that detects the gas pressure in the upstream flow path of the grooved pump section, and a second pressure detection section that calculates the gas pressure in the downstream flow path of the grooved pump section, and the calculation device calculates the state of the deposits based on the gas pressure detected by the first pressure detection section and the second pressure detection section. This allows the accumulation state of deposits in the thread groove pump section to be estimated. (11) In an embodiment according to the eleventh aspect, in the vacuum pump system of the eighth aspect, the vacuum pump has, in order from the upstream side, the turbo pump unit and the thread groove pump unit, the vacuum pump has, in order from the upstream side, the turbo pump unit and the thread groove pump unit, the pressure detection unit includes a first pressure detection unit that detects the gas pressure in the upstream flow path of the turbo pump unit and a second pressure detection unit that calculates the gas pressure in the downstream flow path of the thread groove pump unit, and the calculation device calculates the state of the deposit based on the gas pressure detected by the first pressure detection unit and the second pressure detection unit. This makes it possible to estimate the state of deposits in the exhaust flow path of the turbomolecular pump. (12) In an embodiment according to the twelfth aspect, in the vacuum pump system of the eighth aspect, the vacuum pump has, in order from the upstream side, the turbo pump section and the thread groove pump section, and the pressure detection section includes a first pressure detection section that detects the gas pressure in the upstream flow path of the turbo pump section, a second pressure detection section that detects the gas pressure in the downstream flow path of the turbo pump section, and a third pressure detection section that calculates the gas pressure in the downstream flow path of the thread groove pump section, and the calculation device calculates the state of the deposits based on the gas pressures detected by the first to third pressure detection sections. This allows the accumulation state of deposits in the turbo pump section and the thread groove pump section to be estimated.

[0056] The present invention is not limited to the above-described embodiments, and other embodiments that are conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0057] 1, 1A: turbomolecular pump, 1B: vacuum pump system, 2: base, 3: pump rotor, 4: motor, 12: controller, 20: fixed blade, 21a: stator cylindrical portion, 24: deposit estimation portion, 30: rotor blade, 31a: rotor cylindrical portion, 60: base, 61: casing, 71 to 74: gas flow path, 80, 95: pressure regulating valve, 110, 120, 130, 140, 150: vacuum gauge, 200: external server, 201: communication I / F, 202: deposit estimation portion, 203: memory portion, 400: communication I / F

Claims

1. a vacuum pump including a turbo pump section, a thread groove pump section, an intake port, an exhaust port, and a pressure detection section that detects gas pressure in a gas flow path through which gas taken in from the intake port flows to the exhaust port, the pressure detection section including a first pressure detection element that detects gas pressure in a flow path upstream of a top stage blade of the turbo pump section, and a second pressure detection element that detects gas pressure in a flow path downstream of the turbo pump section and upstream of the thread groove pump section; a computing device that computes a state of deposits accumulated in the turbo pump section based on a difference between the gas pressure detected by the first pressure detection element and the gas pressure detected by the second pressure detection element, Vacuum pump system.

2. a vacuum pump including a turbo pump section, a thread groove pump section, an intake port, an exhaust port, and a pressure detection section that detects gas pressure in a gas flow path through which gas taken in from the intake port flows to the exhaust port, the pressure detection section including a first pressure detection element that detects the gas pressure in the flow path upstream of the uppermost blade of the turbo pump section, a second pressure detection element that detects the gas pressure in the flow path downstream of the turbo pump section and upstream of the thread groove pump section, and a third pressure detection element that detects the gas pressure in the flow path downstream of the thread groove pump section; a computing device that calculates the state of deposits accumulated in the turbo pump section based on a difference between the gas pressure detected by the first pressure detection element and the gas pressure detected by the second pressure detection element, and that calculates the state of deposits accumulated in the thread groove pump section based on a difference between the gas pressure detected by the second pressure detection element and the gas pressure detected by the third pressure detection element, Vacuum pump system.

3. 3. The vacuum pump system according to claim 1, A vacuum pump system, wherein the first pressure detection element detects a gas pressure in a flow path of the intake port.

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