WO2023182489A1 - Evacuation system, vacuum pump, and method of cleaning vacuum pump - Google Patents

Evacuation system, vacuum pump, and method of cleaning vacuum pump Download PDF

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Publication number
WO2023182489A1
WO2023182489A1 PCT/JP2023/011783 JP2023011783W WO2023182489A1 WO 2023182489 A1 WO2023182489 A1 WO 2023182489A1 JP 2023011783 W JP2023011783 W JP 2023011783W WO 2023182489 A1 WO2023182489 A1 WO 2023182489A1
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Prior art keywords
gas
pump
vacuum pump
temperature
flow path
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PCT/JP2023/011783
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French (fr)
Japanese (ja)
Inventor
成燦 趙
克巳 西村
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エドワーズ株式会社
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Publication of WO2023182489A1 publication Critical patent/WO2023182489A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
    • F04B37/14—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use to obtain high vacuum
    • F04B37/16—Means for nullifying unswept space
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
    • F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/20—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy
    • H01L21/2003—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy characterised by the substrate
    • H01L21/2015—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy characterised by the substrate the substrate being of crystalline semiconductor material, e.g. lattice adaptation, heteroepitaxy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
    • H01L21/3065—Plasma etching; Reactive-ion etching

Definitions

  • the present invention relates to a vacuum evacuation system, a vacuum pump, and a method for cleaning a vacuum pump.
  • a semiconductor, an insulator, a metal film, etc. are deposited on a semiconductor wafer, and a dry etching process or CVD (Chemical Vapor Deposition) is performed to form a film using a chemical vapor phase reaction.
  • Various gases are used in process chambers, such as silane (SiH4) gas.
  • SiH4 gas silane
  • the used gas discharged from the process chamber is sucked in by a dry pump, etc., and then introduced into the abatement device via the gas exhaust piping, where the abatement process is performed.
  • Patent Document 1 see Patent Document 1.
  • the dry pump known in Patent Document 1 is explained using the reference numerals used in Patent Document 1, and includes a pump casing 23 having a plurality of pump chambers 22a, 22b, 22c, 22d, 22e, and 22f. , rotors 24a, 24b, 24c, 24d, 24e, and 24f disposed in the pump chambers 22a to 22f, respectively, and these rotors 24a to 24f are integrally fixed, and these rotors 24a to 24f are A pair of rotating shafts 25a, 25b to be rotated together, a pair of gears 26a, 26b for synchronously rotating the pair of rotating shafts 25a, 25b, and a rotating shaft 25a, via this pair of gears 26a, 26b. It has a motor 27 as a rotational drive mechanism for rotating the pump 25b, and bearings 28a, 28a, 28b, and 28b that respectively support the rotating shafts 25a and 25b in the pump casing 23.
  • the gas remaining inside the dry pump is solidified as a film or powder and becomes a deposit (mainly SiO2: silica), and this deposit disappears in a short period of time (2 to 3 months). It adheres to the inside of the dry pump and causes operational problems.
  • the rotors 24a to 24f may become locked, making it impossible to restart the pump. This is related to the fact that during operation, the pump chambers 22a to 22f become hot and expand, and the rotating shaft is displaced in the thrust direction. Taking these into account, the design is such that when the pump is stopped, the gap between both sides of the rotor and the inner surfaces of both sides of the pump chamber widens on one side (left side) and narrows on the other side (right side). This is because the gap on one side when stopped is designed to be about several tens to several hundreds of ⁇ m.
  • the present invention has been proposed to achieve the above object, and the invention according to claim 1 includes a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, and a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust.
  • the vacuum pump can be started by introducing a high-temperature inert gas into the gas flow path of the vacuum pump in a stopped state to raise the temperature to approximately the same as the temperature during normal operation of the vacuum pump.
  • a first inert gas introduction unit that expands the gas flow path; and a cleaning material introduction unit that introduces a cleaning material into the gas flow path to remove the deposits. I will provide a.
  • the gas flow path of the vacuum pump is set to the temperature at which the vacuum pump normally operates. Introduce a high-temperature inert gas that can raise the temperature to approximately the same temperature. Then, by introducing a high-temperature inert gas, the temperature inside the vacuum pump is returned to approximately the same temperature as during normal operation, and the deposits adhering to the inside of the vacuum pump are melted by the heated heat and the rotor is locked. Release. Then, when the rotor is unlocked and can rotate, a cleaning material that reacts with the process gas is introduced into the gas flow path to remove deposits in the gas flow path.
  • the temperature substantially equal to the temperature during normal operation is a temperature range in which deposits adhering to the inside of the vacuum pump can be melted and the lock of the rotor can be released.
  • the invention according to claim 2 provides the vacuum evacuation system in the configuration according to claim 1, wherein the first inert gas introduction unit introduces the inert gas approximately in the middle of the gas flow path. do.
  • a high-temperature inert gas that can raise the temperature of the vacuum pump to a temperature approximately equal to the temperature during normal operation is introduced into approximately the middle of the gas flow path. This is because if the inert gas is introduced from the inlet at the end of the gas flow path to the outlet at the end rather than approximately in the middle of the gas flow path, the pump chamber at the end entrance side will be at a high temperature. The heat of the inert gas quickly raises the temperature to the normal operating temperature, but by the time the inert gas reaches the pump chamber on the outlet side farthest from the inlet, it has cooled down and has to rise to the normal operating temperature. It takes time.
  • the heat of the inert gas is transferred from the intermediate position to both the inlet and outlet sides, and the pump chambers on both the inlet and outlet sides are simultaneously heated at approximately the same level. It can be heated up to a certain temperature. Thereby, deposits inside the vacuum pump can be removed more quickly and cleanly, and maintenance work etc. can be completed.
  • the invention according to claim 3 is the configuration according to claim 1 or 2, in which a second inert gas introduction unit introduces an inert gas into the gas flow path in order to protect the seal portion of the vacuum pump.
  • a vacuum exhaust system further comprising: a position where the first inert gas introduction unit introduces the inert gas and a position where the second inert gas introduction unit introduces the inert gas into the gas flow path are the same. I will provide a.
  • the second inert gas introduction unit uses the inlet into which the sealing inert gas is introduced, and the first inert gas introduction unit introduces the high temperature inert gas into the gas flow path. Therefore, there is no need for the first inert gas introduction unit to provide a new inlet for introducing high temperature inert gas into the gas flow path, and the structure can be simplified.
  • the invention according to claim 4 provides a vacuum pump having the configuration according to any one of claims 1 to 3, wherein the vacuum pump is a positive displacement vacuum pump.
  • the invention according to claim 5 is a method for cleaning a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, wherein deposits of the process gas are deposited and the gas flow of the vacuum pump is stopped. introducing a high-temperature inert gas into the vacuum pump to a temperature substantially equal to the temperature during normal operation of the vacuum pump to expand the gas flow path so that the pump can be started; and cleaning. introducing a material into the gas flow path to remove the deposits.
  • the gas flow path of the vacuum pump is exposed to the temperature at which the vacuum pump normally operates. Introduce a high-temperature inert gas that can raise the temperature to approximately the same temperature. Then, by introducing a high-temperature inert gas, the temperature inside the vacuum pump is returned to approximately the same temperature as during normal operation, and the deposits adhering to the inside of the vacuum pump are melted by the heated heat and the rotor is locked. Release.
  • the temperature substantially equal to the temperature during normal operation here is a temperature range in which deposits adhering to the inside of the vacuum pump can be melted and the lock of the rotor can be released.
  • the invention according to claim 6 is a method for cleaning a vacuum pump for exhausting a process gas containing condensable gas or oxidized dust, wherein the process gas is discharged into a gas flow path in the vacuum pump before the vacuum pump is stopped.
  • a method for cleaning a vacuum pump is provided that includes the step of introducing a cleaning material that reacts with a gas to remove deposits caused by the process gas.
  • a cleaning material that reacts with the process gas is introduced into the gas flow path of the vacuum pump to remove deposits that have adhered inside the vacuum pump.
  • deposits inside the vacuum pump can be quickly and cleanly removed without stopping the operation of the vacuum pump. Therefore, in this vacuum pump cleaning method, deposits within the vacuum pump can be removed without stopping the vacuum pump, contributing to improved productivity.
  • the gas flow path of the vacuum pump has a temperature at which the vacuum pump normally operates.
  • a cleaning material that reacts with the process gas is introduced into the gas flow path to remove deposits in the gas flow path, thereby removing more deposits within the vacuum pump. It can be removed quickly and cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
  • FIG. 1 is a block diagram showing a schematic overall configuration of an exhaust gas treatment apparatus in a semiconductor manufacturing process as a first example according to an embodiment of the present invention
  • FIG. It is a schematic side sectional view which shows typically the internal structure of the dry pump in the exhaust gas treatment device same as the above.
  • 3 is a sectional view taken along line AA in FIG. 2.
  • FIG. 3 is an example of data showing how solid SiO2 is changed into gaseous SiF4 by NF3 plasma and is discharged from a dry pump.
  • It is a schematic side sectional view which shows typically the internal structure of another dry pump in the same exhaust gas treatment apparatus as a 2nd Example. 6 is a sectional view taken along line BB in FIG. 5.
  • FIG. It is a figure showing an example of maintenance judgment criteria in a control device.
  • the present invention provides a vacuum evacuation system, a vacuum pump, and a vacuum pump that can easily recover from a stopped state in which a dry pump has stopped and a deposition section has blocked the gas flow path of the vacuum pump, making it impossible to restart the pump.
  • a vacuum pump for evacuating a process gas containing condensable gas or oxidized dust, and a stop when deposits of the process gas block the gas flow path of the vacuum pump A high-temperature inert gas that is approximately equal to the temperature in the gas flow path during normal operation of the vacuum pump is introduced into the gas flow path of the vacuum pump in a state where the gas flow is controlled so that the vacuum pump can be started.
  • a configuration comprising: a first inert gas introduction unit that expands the channel; and a cleaning material introduction unit that introduces a cleaning material that reacts with the process gas into the gas flow channel to remove the deposits. This was achieved by doing this.
  • drawings may be exaggerated by enlarging or otherwise exaggerating characteristic parts in order to make the features easier to understand, and the dimensional ratios of the constituent elements are not necessarily the same as in reality.
  • hatching of some components may be omitted in order to make the cross-sectional structure of the components easier to understand.
  • FIG. 1 to 3 show an exhaust gas treatment apparatus in a semiconductor manufacturing process as an example according to an embodiment of the present invention.
  • FIG. 1 is a block diagram showing the overall general configuration of the exhaust gas treatment apparatus
  • FIG. 3 is a schematic side sectional view schematically showing the internal structure of the dry pump 17 in the processing apparatus
  • FIG. 3 is a sectional view taken along the line AA in FIG.
  • the exhaust gas treatment device is controlled according to a predetermined procedure by a program within a control device 10.
  • a semiconductor wafer 12 is housed inside the process chamber 11, and a process gas for processing and a cleaning gas for cleaning are supplied through gas supply piping 13, respectively.
  • a dry pump 17 as a vacuum pump is connected to the process chamber 11 via a gas pipe 14, and the process chamber 11 is reduced in pressure to a high vacuum by driving the dry pump 17.
  • the process gas containing condensable gas or oxidized dust such as silane (SiH4) gas, and ClF3 (chlorine trifluoride), NF3 (trifluoride trifluoride), which has been processed inside the process chamber 11,
  • a cleaning gas such as nitrogen), HCl (hydrogen chloride) (hereinafter, these process gases and cleaning gases are collectively referred to as "used gas G1") is introduced into the downstream dry pump 17 through the gas pipe 14.
  • used gas G1 used gas
  • the internal structure of the dry pump 17 is shown in FIGS. 2 and 3.
  • the used gas G1 from the process chamber 11 is sucked into the dry pump 17 through the gas inlet 17a, and the used gas G1 is gradually introduced into the dry pump 17 in six stages. That is, the first stage pump chamber 22a, the second stage pump chamber 22b, the third stage pump chamber 22c, the fourth stage pump chamber 22d, the fifth stage pump chamber 22e, and the sixth stage pump.
  • the pressure is gradually increased through the chambers 22f in this order.
  • the used gas G1 pressurized to near atmospheric pressure in the dry pump 17 is discharged from the gas exhaust port 17b into the gas exhaust pipe 18, and from the gas exhaust pipe 18. It is sent to the abatement device 19, where it is rendered harmless and then discharged into the atmosphere. Therefore, one end of the gas exhaust pipe 18 is connected to the gas exhaust port 17b of the dry pump 17, and the other end is connected to the gas inlet 19a of the abatement device 19.
  • the restart material supply pipe 21a is connected to the first inert gas introduction unit 20a, and the other end is connected to the restart material introduction port 17c via an on-off valve 31a.
  • the restart material inlet 17c is located in an intermediate pump chamber among a plurality of (six in this embodiment) pump chambers 22a to 22f, or in the third stage pump chamber 22c in this embodiment. It is provided in the pump casing 23 corresponding to the location.
  • a high temperature (for example, 400°C) inert gas G2 hot N2, etc.
  • is sent from the first inert gas introduction unit 20a by opening and closing the on-off valve 31a. is adapted to be introduced into the dry pump 17.
  • Opening/closing control of the on-off valve 31a is performed under control of the control device 10. That is, when the on-off valve 31a is open, the high temperature inert gas G2 enters the pump casing 23 through the restart material inlet 17c. Then, when the high-temperature inert gas G2 is fed into the pump casing 23 from the restart material inlet 17c for a certain period of time (for example, about 2 hours), the inside of the pump casing 23 is heated to approximately the same high temperature as when the dry pump 17 is operating.
  • the plasma supply pipe 21b has one end connected to the gas inlet 17a of the pump casing 23 via the on-off valve 31b and the gas pipe 14, and the other end connected to the cleaning material supply unit 30.
  • NF3 plasma which is a cleaning material G4 for cleaning the inside of the dry pump 17
  • NF3 plasma which is a cleaning material G4 for cleaning the inside of the dry pump 17
  • the cleaning material G4 includes, in addition to NF3 plasma (F radicals), plasma (F radicals), HF (hydrogen fluoride), water vapor, silicon chloride, and the like. Opening/closing control of the on-off valve 31b is performed under control of the control device 10. That is, when the on-off valve 31b is open, the cleaning material G4 from the cleaning material supply unit 30 enters the pump casing 23 through the gas inlet 17a.
  • the cleaning material G4 is flowed into the pump casing 23 after the dry pump 17 is restarted. Then, when the cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23, the product reacts with F radicals in the plasma and is released as a gas, so that the deposits in the dry pump 17 are almost eliminated. Then, the deposits in the dry pump 17 that are released as a gas can flow into the gas exhaust pipe 18 from the gas exhaust port 17b and be fed into the abatement device 19.
  • the dry pump 17 shown in FIGS. 2 and 3 is a positive displacement vacuum pump, and has a plurality of pump chambers (six in this embodiment), namely, a first stage pump chamber 22a, a second stage pump chamber 22b, A pump casing 23 has a third-stage pump chamber 22c, a fourth-stage pump chamber 22d, a fifth-stage pump chamber 22e, and a sixth-stage pump chamber 22f.
  • the pump casing 23 includes bearings 28a, 28a, 28b, and 28b that respectively support rotating shafts 25a and 25b.
  • the pump casing 23 is formed by sequentially stacking a plurality of stators 23a in the axial direction in consideration of ease of assembly. Furthermore, as shown in FIG. 3, the pump casing 23 has a generally rectangular cross section taken at right angles to the rotating shafts 25a, 25b.
  • the rotors 24a to 24f integrally fixed to the rotating shaft 25a and the rotors 24a to 24f integrally fixed to the rotating shaft 25b are rotated into the pump chamber 22a. ⁇ 22f, they rotate in opposite directions.
  • the rotors 24a to 24f respectively attached to the rotating shafts 25a and 25b in this embodiment are cocoon-shaped roots rotors, and are rotated at 90° while maintaining a small gap without contacting each other. Rotates synchronously with a phase difference of
  • the used gas G1 is sucked into the first stage pump chamber 22a from the gas inlet 17a communicating with the vacuum target space.
  • the used gas G1 is sequentially sucked into the dry pump through the gas exhaust pipe 18 communicating with the gas exhaust port 17b of the sixth stage pump chamber 22f. 17, and the vacuum target space becomes a vacuum state.
  • the used gas G1 is discharged while being compressed in each of the pump chambers 22a, 22b, 22c, 22d, 22e, and 22f, so the temperature of the used gas G1 increases and the temperature of the pump casing 23 increases. The temperature also rises. Note that among the pump chambers 22a, 22b, 22c, 22d, 22e, and 22f, the used gas G1 is the most used on the discharge side of the sixth stage pump chamber 22f, where the difference in pressure between the suction side and the discharge side is large. The temperature of gas G1 increases.
  • the temperature of the used gas G1 here is relatively high, for example, about 150 to 200°C.
  • the used gas G1 discharged from the sixth stage pump chamber 22f passes through the gas exhaust pipe 18 and heads to the abatement device 19 located several meters ahead.
  • the gas remaining inside the dry pump 17 is solidified as a film or powder and becomes a deposit (mainly SiO2: silica), and this deposit remains for a short period of time ( After 2 to 3 months), it adheres to the inside of the dry pump and causes operational problems. Furthermore, if the dry pump 17 is temporarily stopped for maintenance or other reasons, the rotors 24a to 24f may become locked, making it impossible to restart the pump. As mentioned above, this is because the gap between the rotor 24a to 24f and the inner wall surface of the pump chambers 22a to 22f, which is the fixed side, becomes high during operation.
  • the gap between both side surfaces of the rotors 24a to 24f and both inner surfaces of the pump chambers 22a to 22f widens on one side (left side) and narrows on the other side (right side) when the pump is stopped. This is because the gap on one side when stopped is designed to be approximately several tens to several hundreds of ⁇ m.
  • the on-off valve 31a is opened via the control device 10, and the high-temperature inert gas G2 of about 400° C. is introduced into the pump casing 23 from the restart material inlet 17c from the first inert gas introduction unit 20a. for approximately several hours (for example, about 2 hours).
  • the restart material inlet 17c is provided in the fourth stage pump chamber 22d, and the high temperature inert gas G2 of approximately 400° C.
  • the pump casing 23 is introduced into the pump casing 23 from the fourth stage pump chamber 22d.
  • This is the third stage pump chamber 22c, the second stage pump chamber 22b, the first stage pump chamber 22a, the fifth stage pump chamber 22e, the sixth stage pump chamber 22f, and the gas inlet 17a side. It spreads toward both sides of the gas discharge port 17b, heating the entire inside of the pump casing 23 to a high speed and high temperature. Due to this heating, the temperature inside the pump casing 23 becomes approximately the same high temperature (approximately 150° C. to 200° C.) as during operation of the dry pump 17, and both side surfaces of the rotors 24a to 24f and both inner surfaces of the pump chambers 22a to 22f are heated.
  • high-temperature inert gas G2 is introduced to heat the inside of the pump casing 23 to a temperature approximately equal to the temperature during normal operation of the dry pump 17, so that the dry pump 17 can be started.
  • the inert gas G2 introduced into the pump casing 23 is passed through the gas exhaust pipe 18 and sent into the abatement device 19.
  • the temperature of the inert gas G2 sent into the pump casing 23 is approximately 400° C. in anticipation of a temperature drop in the supply pipe before being introduced into the pump casing 23.
  • the heating temperature is approximately 150°C to 200°C, but other temperatures (lower temperature or high temperature).
  • the on-off valve 31b is opened via the control device 10, and the cleaning material G4, which is NF3 plasma (F radical), is supplied from the cleaning material supply unit 30 to the gas inlet port. 17a into the pump casing 23, and the cleaning material G4 flows into the pump casing 23.
  • the cleaning process here is a step in which the cleaning material G4 is introduced into the gas flow path to remove deposits. Further, the cleaning material G4 flowing into the pump casing 23 is flowed into the abatement device 19 from the gas exhaust port 17b through the gas exhaust pipe 18.
  • the cleaning material G4 fed into the pump casing 23 flows through the pump casing 23, the product reacts with F radicals in the plasma and is released as a gas, removing deposits in the dry pump 17. Almost disappears. Further, the deposits in the dry pump 17 released as a gas are flowed together with the cleaning material G4 into the gas exhaust pipe 18 from the gas outlet 17b, and are further sent into the abatement device 19.
  • FIG. 4 shows the difference between NF3 (nitrogen trifluoride) plasma and SiF4 (tetrafluoride) plasma per unit time when cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23 from the gas inlet 17a and discharged from the gas outlet 17b.
  • This is data obtained by measuring each concentration (ppm) of silicon oxide).
  • the vertical axis is the concentration (ppm)
  • the horizontal axis is the elapsed time T.
  • the data in FIG. 4 shows that solid SiO2 (silica) is changed into gaseous SiF4 by NF3 plasma (F ions) and is discharged. That is, in FIG. 4, NF3 plasma is introduced into the pump casing 23 from the gas inlet 17a, and the amount (concentration) of NF3 plasma and the amount of SiF4 (concentration) discharged from the gas inlet 17a from time T0 to time Tn are calculated. Each represents a change in concentration).
  • the reason that the concentration of NF3 plasma during the period from time T1 to T2 is low is because the reaction with SiO2 is progressing. Further, the change to SiF4 peaks around time T2, and thereafter the change to SiF4 gradually decreases.
  • this data also shows that when the cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23 from the gas inlet 17a, solid SiO2 changes to gaseous SiF4 and is discharged from the gas outlet 17b. It can be seen that some SiO2 disappears from inside the pump casing 23.
  • a high-temperature inert gas G2 is introduced into the gas flow path of the pump 17 to raise the temperature to approximately the same as the temperature during normal operation of the dry pump 17, and the temperature inside the dry pump 17 is brought to a temperature close to that during normal operation.
  • the locks of the rotors 24a to 24f can be released and the rotors 24a to 24f can be rotated.
  • the cleaning material G4 that reacts with the process gas G1 is introduced into the gas flow path to remove deposits in the gas flow path. Objects can be removed faster and more cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
  • the restart material supply pipe 21a is connected to the pump casing 23 corresponding to the intermediate pump chamber among the plurality of pump chambers 22a to 22f, that is, the fourth stage pump chamber 22d.
  • a restart material inlet 17c is provided at a location, and high-temperature inert gas G2 is introduced into the pump casing 23 from the third-stage pump chamber 22c, but this is not necessarily the third-stage pump chamber 22c.
  • the gas may be introduced from the gas inlet 17a and flowed from the first stage pump chamber 22a.
  • the effects of introducing from an intermediate pump chamber instead of from the first stage pump chamber 22a are as follows.
  • FIG. 5 and 6 show a second embodiment of the dry pump in the exhaust gas treatment device shown in FIG. 1, and FIG. 5 is a schematic side sectional view schematically showing the internal structure of the dry pump 32, and FIG. is a sectional view taken along line BB in FIG. 5.
  • the entire temperature of the dry pump 17 is maintained at approximately the same high temperature as during operation, from the outside of the pump casing 23 through the restart material inlet 17c into the third stage pump chamber 22c.
  • the pump restart material which is a high temperature (approximately 400°C) inert gas G2 that can be raised to a temperature (approximately 150°C to 200°C)
  • G2 a high temperature inert gas
  • each of the plurality of stators 23a which are stacked in the axial direction and constitute the pump casing 23, has sealing gas grooves 33a on opposing surfaces that extend outside the pump chambers 22d to 22f. It is formed so as to surround it.
  • the sealing gas grooves 33a face each other in the parts forming the pump chambers 22d to 22f to form a seal.
  • a gas flow path 33 is formed therein. Note that the sealing gas flow path 33 will be described with reference to the case where the sealing gas grooves 33a are formed on both sides of the stator 23a, but the sealing gas grooves 33a may be formed only on one side of the stator 23a. I do not care.
  • each pump chamber 22d to 22f in order to maintain the airtightness of each pump chamber 22a to 22f, a space surrounding the outside of each pump chamber 22d to 22f is placed between the stator 23a and each stator 23a, as shown in FIG.
  • An O-ring 35 is closely arranged within the O-ring groove 34.
  • the sealing gas flow path 33 is provided with a gas intake port 42 for introducing the sealing gas G3 and the high-temperature inert gas G2 into each of the pump chambers 22d to 22f.
  • sealing gas G3 which is N2 gas, is flowed (introduced) into each of the pump chambers 22d to 22f of the fourth, fifth, and sixth stages, which are the latter stages.
  • the pump chamber through which the sealing gas G3 flows may be configured to flow only to the final pump chamber (sixth stage pump chamber 22f) where the pressure is highest, or in consideration of heating inside the pump casing 23, Even if the sealing gas passages 33 are provided corresponding to all the pump chambers 22a to 22f, and the high temperature inert gas G2 is made to flow from all the sealing gas passages 33 into all the pump chambers 22a to 22f. good.
  • the sealing gas groove 33a of each stator 23a forming the fourth, fifth, and sixth stage pump chambers 22d to 22f has a sealing gas groove 33a located outside the stator 23a.
  • a sealing gas exhaust port 37b is provided.
  • a sealing gas inlet pipe 38 to which sealing gas G3 is supplied is connected to each sealing gas inlet 36a via an on-off valve 39, and a sealing gas inlet 38 is connected to each sealing gas exhaust pipe connection port 37a.
  • Seal gas discharge pipes 40 through which gas G3 is discharged are connected to each other via on-off valves 41. Further, the sealing gas exhaust pipe 40 is connected to the gas exhaust pipe 18 via the dilution gas introduction section 18a.
  • on-off valves 39 and 41 for example, on-off valves that can adjust the gas flow rate may be used.
  • the first inert gas introduction unit 20a is connected to the sealing gas introduction pipe 38 via a pump restart material supply pipe 43 and an on-off valve 44. Opening/closing control of the on-off valve 44 is performed under control of the control device 10. That is, when flowing the inert gas G2, the on-off valve 39 and the on-off valve 41 are closed, and the on-off valve 44 is opened. Then, the high-temperature inert gas G2 from the first inert gas introduction unit 20a enters the sealing gas passage 33 from the pump restart material supply pipe 43 through the sealing gas introduction port 36a, and further gas It flows through the intake port 42 into each of the fourth, fifth, and sixth stage pump chambers 22d to 22f.
  • this high-temperature inert gas G2 spreads throughout the inside of the pump casing 23, raising the temperature inside the pump casing 23. Thereafter, the gas is discharged into the gas exhaust pipe 18 through the gas discharge port 17b, and sent to the abatement device 19 via the gas exhaust pipe 18.
  • the sealing gas The temperature inside the dry pump 32 is raised to a temperature approximately equal to the temperature during normal operation (100°C to 190°C) using the high-temperature inert gas G2 flowing into the flow path 33, so that the temperature inside the dry pump 32 becomes normal.
  • the temperature can be quickly returned to near operating temperature. Then, the deposits adhering to the interior of the dry pump 17 are melted by high temperature heat, and the locks of the rotors 24a to 24f are released, allowing the rotors 24a to 24f to rotate.
  • the on-off valve 31b is opened via the control device 10, and the cleaning material G4, which is NF3 plasma, is sent into the pump casing 23 from the gas inlet 17a.
  • G4 flows into the pump casing 23.
  • the cleaning material G4 that has flowed into the pump casing 23 is flown into the abatement device 19 from the gas exhaust port 17b through the gas exhaust pipe 18.
  • the deposits in the dry pump 17 released as a gas are flowed into the gas exhaust pipe 18 from the gas outlet 17b together with the cleaning material G4, and further sent into the abatement device 19.
  • the exhaust gas treatment apparatus when the rotors 24a to 24f of the dry pump 32 are locked due to the process gas accumulation and the dry pump 17 cannot be restarted from a stopped state, the sealing gas flow Since the high temperature inert gas G2 is flowed into the passage 33 to return the temperature inside the dry pump 17 to a temperature close to that during normal operation, the deposits inside the dry pump 32 can be removed more quickly and cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
  • a normal The temperature inside the dry pump 17 is returned to a temperature close to that during normal operation by flowing a high-temperature inert gas G2 to raise the temperature to approximately the same as the temperature during operation, and after restarting the dry pump 17, cleaning material is added to the inside of the dry pump 17. I flushed G4 to eliminate the deposits.
  • a cleaning material G4 that reacts with the process gas is flowed into the gas flow paths of the dry pump 17 and the dry pump 32 in advance to remove deposits (SiO2) caused by the process gas G1. It is also possible to do this.
  • FIG. 7 An example of removing deposits (SiO2) caused by the process gas by flowing a cleaning material G4 that reacts with the process gas into the gas flow paths of the dry pump 17 and the dry pump 32 before stopping the dry pump 17 and the dry pump 32 is shown in FIG. 7 will be used to explain the case of the dry pump 17 shown in FIGS. 1 to 3.
  • FIG. 7 An example shown in FIG. 7 is a case where control is performed by the control device 10. While the dry pump 17 is in operation, the speed 101 of the booster pump, the speed 102 of the dry pump 17, and the current value 103 of the dry pump 17 are respectively input to the control device 10, and these values are monitored for approximately one hour. . If the speed 102 of the dry pump 17 falls below the speed 101 of the booster pump several times during this one hour period, and the current value 103 of the dry pump 17 exceeds the threshold value (for example, 45.0 amperes) several times, , the control device 10 determines that the amount of deposits in the dry pump 17 exceeds the standard.
  • the threshold value for example, 45.0 amperes
  • the control device 10 controls the first inert gas introduction unit 20a and the on-off valve 31b to cause cleaning to react with the process gas G1 from the gas introduction port 17a into the pump casing 23.
  • the material G4 is allowed to flow for a certain period of time to eliminate the deposits that have accumulated inside the pump casing 23. Thereby, deposits adhering to the inside of the dry pump 17 can be removed in advance without stopping the dry pump 17.
  • Control device 11 Process chamber 12: Semiconductor wafer 13: Gas supply piping 17: Dry pump 17a: Gas inlet 17b: Gas outlet 17c: Restart material inlet 18: Gas exhaust piping 19: Abatement device 20a: First inert gas introduction unit 20b: Second inert gas introduction unit 21a: Restart material supply piping 21b: Plasma supply piping 22a: First stage pump chamber 22b: Second stage pump chamber 22c: Third Stage pump chamber 22d : Fourth stage pump chamber 22e : Fifth stage pump chamber 22f : Sixth stage pump chamber 23 : Pump casing 24a : Rotor 24b : Rotor 24c : Rotor 24d : Rotor 24e : Rotor 24f : Rotor 31a: On-off valve 31b: On-off valve 32: Dry pump 33: Seal gas passage 33a: Seal gas groove 36: Seal gas introduction passage 36a: Seal gas introduction port 36b: Seal gas introduction port 37: For seal Gas exhaust passage 37a: Seal gas discharge pipe connection port 37b: Seal gas discharge port 38:

Abstract

[Problem] To provide an evacuation system, a vacuum pump, and a method for cleaning a vacuum pump that enable easy recovery from a stopped state in which a dry pump has stopped and deposits have blocked off a gas flow path of the vacuum pump, making restart impossible. [Solution] The invention is provided with: a vacuum pump for exhausting a process gas that contains condensable gas or oxidized dust; a first inert gas introduction unit for introducing high-temperature inert gas, which is for raising the temperature to substantially the same temperature as when the vacuum pump is running normally, to a gas flow path of the vacuum pump in a stopped state where deposits of the process gas have accumulated, and causing the gas flow path to expand so that the vacuum pump can be started up; and a cleaning material introduction unit for introducing a cleaning material to the gas flow path to remove the deposits.

Description

真空排気システム、真空ポンプ及び真空ポンプのクリーニング方法Vacuum pumping system, vacuum pump and vacuum pump cleaning method
　本発明は、真空排気システム、真空ポンプ及び真空ポンプのクリーニング方法に関するものである。 The present invention relates to a vacuum evacuation system, a vacuum pump, and a method for cleaning a vacuum pump.
　例えば、半導体製造処理プロセスでは、半導体や絶縁体、金属膜等を、半導体ウエハ上に堆積させ、化学気相反応を利用して成膜するＣＶＤ（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ）やドライエッチング処理が行われ、プロセスチャンバにおいて、例えばシラン(ＳｉＨ４)ガス等、各種のガスが使用されている。そして、プロセスチャンバから排出された使用済みのガスは、ドライポンプ等で吸引して、更にガス排気配管を介して除害装置に導入され、その除害装置で除害処理が行われている（例えば、特許文献１参照）。 For example, in a semiconductor manufacturing process, a semiconductor, an insulator, a metal film, etc. are deposited on a semiconductor wafer, and a dry etching process or CVD (Chemical Vapor Deposition) is performed to form a film using a chemical vapor phase reaction. Various gases are used in process chambers, such as silane (SiH4) gas. The used gas discharged from the process chamber is sucked in by a dry pump, etc., and then introduced into the abatement device via the gas exhaust piping, where the abatement process is performed. For example, see Patent Document 1).
　特許文献１で知られるドライポンプは、特許文献１で使用している符号を用いて使用して説明すると、複数個のポンプ室２２ａ、２２ｂ、２２ｃ、２２ｄ、２２ｅ、２２ｆを有するポンプケーシング２３と、該ポンプ室２２ａ～２２ｆ内にそれぞれ配設されるロータ２４ａ、２４ｂ、２４ｃ、２４ｄ、２４ｅ、２４ｆと、これらのロータ２４ａ～２４ｆが各々一体的に固設され、これらのロータ２４ａ～２４ｆを一体に回転させる１対の回転軸２５ａ、２５ｂと、この一対の回転軸２５ａ、２５ｂを同期回転させるための一対のギア２６ａ、２６ｂと、この一対のギア２６ａ、２６ｂを介して回転軸２５ａ、２５ｂを回転させるための回転駆動機構としてのモータ２７と、ポンプケーシング２３に回転軸２５ａ、２５ｂをそれぞれ軸支する軸受２８ａ、２８ａ、２８ｂ、２８ｂと、を有している。 The dry pump known in Patent Document 1 is explained using the reference numerals used in Patent Document 1, and includes a pump casing 23 having a plurality of pump chambers 22a, 22b, 22c, 22d, 22e, and 22f. , rotors 24a, 24b, 24c, 24d, 24e, and 24f disposed in the pump chambers 22a to 22f, respectively, and these rotors 24a to 24f are integrally fixed, and these rotors 24a to 24f are A pair of rotating shafts 25a, 25b to be rotated together, a pair of gears 26a, 26b for synchronously rotating the pair of rotating shafts 25a, 25b, and a rotating shaft 25a, via this pair of gears 26a, 26b. It has a motor 27 as a rotational drive mechanism for rotating the pump 25b, and bearings 28a, 28a, 28b, and 28b that respectively support the rotating shafts 25a and 25b in the pump casing 23.
　このようなドライポンプは、該ドライポンプの内部に残留するガスが、膜や粉として固形化されて堆積物（主にＳｉＯ２：シリカ）となり、この堆積物が短期間（２～３ヶ月）でドライポンプの内部に付着し、運転不具合を発生させる。 In such a dry pump, the gas remaining inside the dry pump is solidified as a film or powder and becomes a deposit (mainly SiO2: silica), and this deposit disappears in a short period of time (2 to 3 months). It adheres to the inside of the dry pump and causes operational problems.
　また、メンテナンスやそれ以外の事情でドライポンプを一時的に停止させると、ロータ２４ａ～２４ｆがロックしてしまい再起動が不能になることがある。これは、運転時はポンプ室２２ａ～２２ｆが高温になり、ポンプ室２２ａ～２２ｆが拡がることと、回転軸がスラスト方向に変位することに関係する。これらのことを想定して、ポンプ停止時には、ロータの両側面とポンプ室の両側内面との間のギャップが、片側（左側）が広がり、もう片側（右側）が狭くなるように設計しているためであり、停止時における片側のギャップは数１０～数１００μｍ程度に設計されている。そのため、ドライポンプを停止させると、回転軸によるスラスト方向の変位がなくなるとともに高温状態にあったポンプが冷やされて、ロータの両側面とポンプ室の両側内面との間のギャップが狭まり、その間に堆積している堆積物が詰まって固化し、ロータ２４ａ～２４ｆの再起動を妨げる。 Additionally, if the dry pump is temporarily stopped for maintenance or other reasons, the rotors 24a to 24f may become locked, making it impossible to restart the pump. This is related to the fact that during operation, the pump chambers 22a to 22f become hot and expand, and the rotating shaft is displaced in the thrust direction. Taking these into account, the design is such that when the pump is stopped, the gap between both sides of the rotor and the inner surfaces of both sides of the pump chamber widens on one side (left side) and narrows on the other side (right side). This is because the gap on one side when stopped is designed to be about several tens to several hundreds of μm. Therefore, when the dry pump is stopped, the displacement in the thrust direction due to the rotating shaft is eliminated and the pump, which was in a high temperature state, is cooled down, and the gap between both sides of the rotor and the inner surfaces of both sides of the pump chamber narrows. The accumulated deposits become clogged and solidify, preventing the rotors 24a-24f from restarting.
特許第６４１８８３８号公報Patent No. 6418838
　上述したように、従来のドライポンプは、ドライポンプの内部に残留するガスの一部が膜や粉として固形化され、堆積物となってドライポンプの内部に付着し、運転不具合を発生させる問題点があった。 As mentioned above, conventional dry pumps have the problem that some of the gas remaining inside the dry pump solidifies as a film or powder, forms deposits, and adheres to the inside of the dry pump, causing operational problems. There was a point.
　さらに、メンテナンスやそれ以外の事情でドライポンプを一時的に停止させると、ロータがロックしてしまい再起動が不能になることが多発しているという問題点があった。そのため、短期間（例えば、２～３ヶ月）でのオーバーホール（例えば、分解掃除及び内部洗浄など）が必要となり、生産性を低下させる要因の一つになっている。また、一度、ロータのロックが生じると、そのロック状態を解除するまでの作業時間を長く必要とし、作業性が悪いという問題点があった。 Furthermore, there was a problem in that when the dry pump was temporarily stopped for maintenance or other reasons, the rotor often locked and it became impossible to restart it. Therefore, overhaul (eg, disassembly and cleaning, internal cleaning, etc.) is required in a short period of time (eg, 2 to 3 months), which is one of the factors that reduce productivity. Furthermore, once the rotor is locked, it takes a long time to release the locked state, resulting in poor workability.
　そこで、ドライポンプが停止し、堆積部が真空ポンプのガス流路を塞いで再起動が不能になった停止状態からの復帰を容易に行わせることができる真空排気システム、真空ポンプ及び真空ポンプのクリーニング方法を提供するために解決すべき技術的課題が生じてくるのであり、本発明はこの課題を解決することを目的とする。 Therefore, we have developed a vacuum evacuation system that can easily recover from a stopped state in which the dry pump has stopped and the deposition section has blocked the gas flow path of the vacuum pump, making it impossible to restart. In order to provide a cleaning method, a technical problem arises that must be solved, and the present invention aims to solve this problem.
　本発明は上記目的を達成するために提案されたものであり、請求項１に記載の発明は、凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプと、前記プロセスガスの堆積物が堆積し、停止状態の前記真空ポンプのガス流路に、前記真空ポンプの通常運転時の温度と略等しい温度に昇温するための高温の不活性ガスを導入して、前記真空ポンプが起動できるように前記ガス流路を拡張させる第１の不活性ガス導入ユニットと、クリーニング材料を前記ガス流路に導入して、前記堆積物を除去するクリーニング材料導入ユニットと、を備えている真空排気システムを提供する。 The present invention has been proposed to achieve the above object, and the invention according to claim 1 includes a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, and a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust. The vacuum pump can be started by introducing a high-temperature inert gas into the gas flow path of the vacuum pump in a stopped state to raise the temperature to approximately the same as the temperature during normal operation of the vacuum pump. a first inert gas introduction unit that expands the gas flow path; and a cleaning material introduction unit that introduces a cleaning material into the gas flow path to remove the deposits. I will provide a.
　この構成によれば、プロセスガスの堆積物が原因で真空ポンプのロータがロックされ、真空ポンプが停止した状態から再起動できないとき、真空ポンプのガス流路に、真空ポンプが通常運転時の温度と略等しい温度まで昇温させることができる高温の不活性ガスを導入する。そして、高温の不活性ガスの導入で真空ポンプ内の温度を通常運転時の温度と略等しい温度に戻し、真空ポンプ内に付着している堆積物を昇温された熱により溶かしてロータのロックを解除する。そして、ロータのロックが解除されて、該ロータが回転できる状態で、ガス流路にプロセスガスと反応するクリーニング材料を導入してガス流路内の堆積物を除去すると、真空ポンプ内の堆積物をより速く、かつ綺麗に除去することができる。これにより、メンテナンス等を短時間で綺麗に終え、再稼働が可能になる。ここでの通常運転時の温度と略等しい温度とは、真空ポンプ内に付着している堆積物を溶かしてロータのロックを解除可能な温度範囲である。 According to this configuration, when the rotor of the vacuum pump is locked due to process gas deposits and the vacuum pump cannot be restarted from a stopped state, the gas flow path of the vacuum pump is set to the temperature at which the vacuum pump normally operates. Introduce a high-temperature inert gas that can raise the temperature to approximately the same temperature. Then, by introducing a high-temperature inert gas, the temperature inside the vacuum pump is returned to approximately the same temperature as during normal operation, and the deposits adhering to the inside of the vacuum pump are melted by the heated heat and the rotor is locked. Release. Then, when the rotor is unlocked and can rotate, a cleaning material that reacts with the process gas is introduced into the gas flow path to remove deposits in the gas flow path. can be removed more quickly and cleanly. This allows maintenance and other tasks to be completed in a short period of time and restarted operations. Here, the temperature substantially equal to the temperature during normal operation is a temperature range in which deposits adhering to the inside of the vacuum pump can be melted and the lock of the rotor can be released.
　請求項２に記載の発明は、請求項１に記載の構成において、前記第１の不活性ガス導入ユニットは、前記ガス流路の略中間に前記不活性ガスを導入する、真空排気システムを提供する。 The invention according to claim 2 provides the vacuum evacuation system in the configuration according to claim 1, wherein the first inert gas introduction unit introduces the inert gas approximately in the middle of the gas flow path. do.
　この構成によれば、真空ポンプを通常運転時の温度と略等しい温度まで昇温させることができる高温の不活性ガスを、ガス流路の略中間に導入している。これは、ガス流路の略中間でなく、ガス流路の一番端の入口から一番端の出口に向かって不活性ガスを導入すると、一番端の入口側でのポンプ室は高温の不活性ガスの熱で通常運転時の温度まですぐに昇温するが、入口から最も遠い出口側のポンプ室に不活性ガスが届くまでには冷えて、通常運転時の温度まで昇温させるのに時間がかかる。これをガス流路の略中間の位置から導入すると、不活性ガスの熱は中間の位置から入口側と出口側の両方に伝達されて、入口側と出口側の両方のポンプ室を同時に略同じ温度まで昇温できる。これにより、真空ポンプ内の堆積物をより速く、かつ綺麗に除去してメンテナンス作業等を終えることができる。 According to this configuration, a high-temperature inert gas that can raise the temperature of the vacuum pump to a temperature approximately equal to the temperature during normal operation is introduced into approximately the middle of the gas flow path. This is because if the inert gas is introduced from the inlet at the end of the gas flow path to the outlet at the end rather than approximately in the middle of the gas flow path, the pump chamber at the end entrance side will be at a high temperature. The heat of the inert gas quickly raises the temperature to the normal operating temperature, but by the time the inert gas reaches the pump chamber on the outlet side farthest from the inlet, it has cooled down and has to rise to the normal operating temperature. It takes time. When this is introduced from a position approximately in the middle of the gas flow path, the heat of the inert gas is transferred from the intermediate position to both the inlet and outlet sides, and the pump chambers on both the inlet and outlet sides are simultaneously heated at approximately the same level. It can be heated up to a certain temperature. Thereby, deposits inside the vacuum pump can be removed more quickly and cleanly, and maintenance work etc. can be completed.
　請求項３に記載の発明は、請求項１又は２に記載の構成において、前記真空ポンプのシール部を保護するために不活性ガスを前記ガス流路に導入する第２の不活性ガス導入ユニットをさらに備え、前記第１の不活性ガス導入ユニットが前記不活性ガスを導入する位置と前記第２の不活性ガス導入ユニットが前記ガス流路に導入する位置は、同一である、真空排気システムを提供する。 The invention according to claim 3 is the configuration according to claim 1 or 2, in which a second inert gas introduction unit introduces an inert gas into the gas flow path in order to protect the seal portion of the vacuum pump. A vacuum exhaust system further comprising: a position where the first inert gas introduction unit introduces the inert gas and a position where the second inert gas introduction unit introduces the inert gas into the gas flow path are the same. I will provide a.
　この構成によれば、第２の不活性ガス導入ユニットがシール用の不活性ガスを導入している入口を使用して、第１の不活性ガス導入ユニットが高温の不活性ガスをガス流路に導入するので、第１の不活性ガス導入ユニットが高温の不活性ガスをガス流路に導入するための新たな入口を設ける必要が無くなり、構造の簡略化が可能になる。 According to this configuration, the second inert gas introduction unit uses the inlet into which the sealing inert gas is introduced, and the first inert gas introduction unit introduces the high temperature inert gas into the gas flow path. Therefore, there is no need for the first inert gas introduction unit to provide a new inlet for introducing high temperature inert gas into the gas flow path, and the structure can be simplified.
　請求項４に記載の発明は、請求項１から３のいずれかに１項に記載の構成において、前記真空ポンプは、容積式真空ポンプである、真空ポンプを提供する。 The invention according to claim 4 provides a vacuum pump having the configuration according to any one of claims 1 to 3, wherein the vacuum pump is a positive displacement vacuum pump.
　この構成によれば、ポンプ内の堆積物をより速く、かつ綺麗に除去してメンテナンス作業等を終えることができる、容積式真空ポンプの実現が可能になる。 According to this configuration, it is possible to realize a positive displacement vacuum pump in which deposits inside the pump can be removed more quickly and cleanly and maintenance work etc. can be completed.
　請求項５に記載の発明は、凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプのクリーニング方法であって、前記プロセスガスの堆積物が堆積し、停止状態の前記真空ポンプのガス流路に、前記真空ポンプの通常運転時の温度と略等しい温度に昇温するための高温の不活性ガスを導入して、前記ポンプが起動できるように前記ガス流路を拡張させるステップと、クリーニング材料を前記ガス流路に導入して、前記堆積物を除去するステップと、を含む、真空ポンプのクリーニング方法を提供する。 The invention according to claim 5 is a method for cleaning a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, wherein deposits of the process gas are deposited and the gas flow of the vacuum pump is stopped. introducing a high-temperature inert gas into the vacuum pump to a temperature substantially equal to the temperature during normal operation of the vacuum pump to expand the gas flow path so that the pump can be started; and cleaning. introducing a material into the gas flow path to remove the deposits.
　この方法によれば、プロセスガスの堆積物が原因で真空ポンプのロータがロックされ、真空ポンプが停止した状態から再起動できないとき、真空ポンプのガス流路に、真空ポンプが通常運転時の温度と略等しい温度まで昇温させることができる高温の不活性ガスを導入する。そして、高温の不活性ガスの導入で真空ポンプ内の温度を通常運転時の温度と略等しい温度に戻し、真空ポンプ内に付着している堆積物を昇温された熱により溶かしてロータのロックを解除する。そして、ロータが回転できる状態で、ガス流路にプロセスガスと反応するクリーニング材料を導入して堆積物を除去するので、真空ポンプ内の堆積物をより速く、かつ綺麗に除去してメンテナンス等を終えることができる。また、ここでの通常運転時の温度と略等しい温度とは、真空ポンプ内に付着している堆積物を溶かしてロータのロックを解除可能な温度範囲である。 According to this method, when the rotor of the vacuum pump is locked due to process gas deposits and the vacuum pump cannot be restarted from a stopped state, the gas flow path of the vacuum pump is exposed to the temperature at which the vacuum pump normally operates. Introduce a high-temperature inert gas that can raise the temperature to approximately the same temperature. Then, by introducing a high-temperature inert gas, the temperature inside the vacuum pump is returned to approximately the same temperature as during normal operation, and the deposits adhering to the inside of the vacuum pump are melted by the heated heat and the rotor is locked. Release. Then, while the rotor is still able to rotate, a cleaning material that reacts with the process gas is introduced into the gas flow path to remove deposits, so deposits inside the vacuum pump can be removed more quickly and cleanly, allowing maintenance, etc. I can finish it. Moreover, the temperature substantially equal to the temperature during normal operation here is a temperature range in which deposits adhering to the inside of the vacuum pump can be melted and the lock of the rotor can be released.
　請求項６に記載の発明は、凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプのクリーニング方法であって、前記真空ポンプの停止前に、前記真空ポンプ内のガス流路に前記プロセスガスと反応するクリーニング材料を導入し、前記プロセスガスによる堆積物を除去するステップを含む、真空ポンプのクリーニング方法を提供する。 The invention according to claim 6 is a method for cleaning a vacuum pump for exhausting a process gas containing condensable gas or oxidized dust, wherein the process gas is discharged into a gas flow path in the vacuum pump before the vacuum pump is stopped. A method for cleaning a vacuum pump is provided that includes the step of introducing a cleaning material that reacts with a gas to remove deposits caused by the process gas.
　この方法によれば、真空ポンプが停止する前に、真空ポンプのガス流路に、プロセスガスと反応するクリーニング材料を導入して、真空ポンプ内に付着している堆積物を事前に除去するので、真空ポンプの運転を停止させることなく、真空ポンプ内の堆積物を速く、かつ綺麗に除去できる。したがって、この真空ポンプのクリーニング方法では、真空ポンプを停止させることなく、真空ポンプ内の堆積物の除去を行うことができるので、生産性の向上に寄与する。 According to this method, before the vacuum pump is stopped, a cleaning material that reacts with the process gas is introduced into the gas flow path of the vacuum pump to remove deposits that have adhered inside the vacuum pump. , deposits inside the vacuum pump can be quickly and cleanly removed without stopping the operation of the vacuum pump. Therefore, in this vacuum pump cleaning method, deposits within the vacuum pump can be removed without stopping the vacuum pump, contributing to improved productivity.
　本発明によれば、プロセスガスの堆積部が原因で真空ポンプのロータがロックされ、真空ポンプが停止した状態から再起動できないとき、真空ポンプのガス流路に、真空ポンプが通常運転時の温度と略等しい温度まで昇温させることができる高温の不活性ガスを導入して真空ポンプ内の温度を通常運転時の温度に戻し、真空ポンプ内に付着している堆積物を高温の熱で溶かしてロータのロックを解除し、ロータが回転できる状態で、ガス流路にプロセスガスと反応するクリーニング材料を導入してガス流路内の堆積物を除去するので、真空ポンプ内の堆積物をより速く、かつ綺麗に除去することができる。これにより、メンテナンス等を短時間で綺麗に終えることができる。 According to the present invention, when the rotor of the vacuum pump is locked due to the accumulation of process gas and the vacuum pump cannot be restarted from a stopped state, the gas flow path of the vacuum pump has a temperature at which the vacuum pump normally operates. By introducing a high-temperature inert gas that can raise the temperature to approximately the same as With the rotor unlocked and the rotor allowed to rotate, a cleaning material that reacts with the process gas is introduced into the gas flow path to remove deposits in the gas flow path, thereby removing more deposits within the vacuum pump. It can be removed quickly and cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
本発明の実施形態による第１実施例としての半導体製造処理プロセスにおける排ガス処理装置の概略全体構成を示すブロック図である。1 is a block diagram showing a schematic overall configuration of an exhaust gas treatment apparatus in a semiconductor manufacturing process as a first example according to an embodiment of the present invention; FIG. 同上排ガス処理装置におけるドライポンプの内部構造を模式的に示す概略側面断面図である。It is a schematic side sectional view which shows typically the internal structure of the dry pump in the exhaust gas treatment device same as the above. 図２のＡ－Ａ断面図である。3 is a sectional view taken along line AA in FIG. 2. FIG. ＮＦ３のプラズマによって固体のＳｉＯ２が気体のＳｉＦ４に変化してドライポンプから排出されていく様子を示している一データ一例の図である。FIG. 3 is an example of data showing how solid SiO2 is changed into gaseous SiF4 by NF3 plasma and is discharged from a dry pump. 第２実施例としての同上排ガス処理装置における他のドライポンプの内部構造を模式的に示す概略側断面図である。It is a schematic side sectional view which shows typically the internal structure of another dry pump in the same exhaust gas treatment apparatus as a 2nd Example. 図５のＢ－Ｂ線断面図である。6 is a sectional view taken along line BB in FIG. 5. FIG. 制御装置におけるメンテナンス判断基準の一例を示す図である。It is a figure showing an example of maintenance judgment criteria in a control device.
　本発明は、ドライポンプが停止し、堆積部が真空ポンプのガス流路を塞いで再起動が不能になった停止状態からの復帰を容易に行わせることができる真空排気システム、真空ポンプ及び真空ポンプのクリーニング方法を提供するという目的を達成するために、凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプと、前記プロセスガスの堆積物が前記真空ポンプのガス流路を塞いだ停止状態の前記真空ポンプのガス流路に、前記真空ポンプの通常運転時における前記ガス流路内の温度と略等しい高温の不活性ガスを導入して、前記真空ポンプが起動できるように前記ガス流路を拡張させる第１の不活性ガス導入ユニットと、前記プロセスガスと反応するクリーニング材料を前記ガス流路に導入して、前記堆積物を除去するクリーニング材料導入ユニットと、を備えている構成とすることにより実現した。 The present invention provides a vacuum evacuation system, a vacuum pump, and a vacuum pump that can easily recover from a stopped state in which a dry pump has stopped and a deposition section has blocked the gas flow path of the vacuum pump, making it impossible to restart the pump. To achieve the objective of providing a method for cleaning a pump, a vacuum pump for evacuating a process gas containing condensable gas or oxidized dust, and a stop when deposits of the process gas block the gas flow path of the vacuum pump; A high-temperature inert gas that is approximately equal to the temperature in the gas flow path during normal operation of the vacuum pump is introduced into the gas flow path of the vacuum pump in a state where the gas flow is controlled so that the vacuum pump can be started. A configuration comprising: a first inert gas introduction unit that expands the channel; and a cleaning material introduction unit that introduces a cleaning material that reacts with the process gas into the gas flow channel to remove the deposits. This was achieved by doing this.
　以下、本発明の実施形態に係る一実施例を添付図面に基づいて詳細に説明する。なお、以下の実施例において、構成要素の数、数値、量、範囲等に言及する場合、特に明示した場合及び原理的に明らかに特定の数に限定される場合を除き、その特定の数に限定されるものではなく、特定の数以上でも以下でも構わない。 Hereinafter, an example according to an embodiment of the present invention will be described in detail based on the accompanying drawings. In addition, in the following examples, when referring to the number, numerical value, amount, range, etc. of constituent elements, unless it is specifically specified or it is clearly limited to a specific number in principle, the specific number The number is not limited, and may be more than or less than a certain number.
　また、構成要素等の形状、位置関係に言及するときは、特に明示した場合及び原理的に明らかにそうでないと考えられる場合等を除き、実質的にその形状等に近似又は類似するもの等を含む。 In addition, when referring to the shape or positional relationship of constituent elements, etc., unless it is specifically specified or it is clearly considered that it is not the case in principle, etc., we refer to things that are substantially similar to or similar to the shape, etc. include.
　また、図面は、特徴を分かり易くするために特徴的な部分を拡大する等して誇張する場合があり、構成要素の寸法比率等が実際と同じであるとは限らない。また、断面図では、構成要素の断面構造を分かり易くするために、一部の構成要素のハッチングを省略することがある。 In addition, the drawings may be exaggerated by enlarging or otherwise exaggerating characteristic parts in order to make the features easier to understand, and the dimensional ratios of the constituent elements are not necessarily the same as in reality. Further, in the cross-sectional views, hatching of some components may be omitted in order to make the cross-sectional structure of the components easier to understand.
　また、以下の説明において、上下や左右等の方向を示す表現は、絶対的なものではなく、本発明の真空排気システムの各部が描かれている姿勢である場合に適切であるが、その姿勢が変化した場合には姿勢の変化に応じて変更して解釈されるべきものである。また、実施例の説明の全体を通じて同じ要素には同じ符号を付している。 In addition, in the following explanation, expressions indicating directions such as up and down and left and right are not absolute, and are appropriate when each part of the vacuum pumping system of the present invention is depicted in a posture. If the position changes, the interpretation should be changed according to the change in posture. Further, the same elements are given the same reference numerals throughout the description of the embodiments.
　図１乃至図３は、本発明の実施形態による１実施例としての半導体製造処理プロセスにおける排ガス処理装置を示すもので、図１は排ガス処理装置の概略全体構成を示すブロック図、図２は排ガス処理装置におけるドライポンプ１７の内部構造を模式的に示す概略側面断面図、図３は図２のＡ－Ａ線断面図である。 1 to 3 show an exhaust gas treatment apparatus in a semiconductor manufacturing process as an example according to an embodiment of the present invention. FIG. 1 is a block diagram showing the overall general configuration of the exhaust gas treatment apparatus, and FIG. FIG. 3 is a schematic side sectional view schematically showing the internal structure of the dry pump 17 in the processing apparatus, and FIG. 3 is a sectional view taken along the line AA in FIG.
　まず、排ガス処理装置における全体の概略構成について、図１を主に用い説明する。また、ドライポンプ１７の内部構造としては、図２及び図３を一部用いて説明する。図１に示すように、排ガス処理装置は、制御装置１０内のプログラムにより予め決められた手順に従って制御される。プロセスチャンバ１１の内部には、半導体ウエハ１２が収納され、ガス供給配管１３を通じてプロセス処理のためのプロセスガス、及び、クリーニング処理のためのクリーニングガスがそれぞれ供給されるようになっている。そして、プロセスチャンバ１１よりガス配管１４を介して真空ポンプとしてのドライポンプ１７が接続されており、プロセスチャンバ１１はドライポンプ１７の駆動により高真空にまで減圧されるようになっている。 First, the overall schematic configuration of the exhaust gas treatment device will be explained using mainly FIG. 1. Further, the internal structure of the dry pump 17 will be explained using FIGS. 2 and 3 in part. As shown in FIG. 1, the exhaust gas treatment device is controlled according to a predetermined procedure by a program within a control device 10. As shown in FIG. A semiconductor wafer 12 is housed inside the process chamber 11, and a process gas for processing and a cleaning gas for cleaning are supplied through gas supply piping 13, respectively. A dry pump 17 as a vacuum pump is connected to the process chamber 11 via a gas pipe 14, and the process chamber 11 is reduced in pressure to a high vacuum by driving the dry pump 17.
　すなわち、前記プロセスチャンバ１１の内部で処理済みとなった、凝縮性ガス又は酸化粉塵を含むプロセスガス、例えばシラン(ＳｉＨ４)ガス等のプロセスガス及びＣｌＦ３(三フッ化塩素)、ＮＦ３(三フッ化窒素)、ＨＣｌ(塩化水素)等のクリーニングガス(以下、これらプロセスガス及びクリーニングガスを総称して「使用済みのガスＧ１」という)は、ガス配管１４を通って下流のドライポンプ１７に導入される。 That is, the process gas containing condensable gas or oxidized dust, such as silane (SiH4) gas, and ClF3 (chlorine trifluoride), NF3 (trifluoride trifluoride), which has been processed inside the process chamber 11, A cleaning gas such as nitrogen), HCl (hydrogen chloride) (hereinafter, these process gases and cleaning gases are collectively referred to as "used gas G1") is introduced into the downstream dry pump 17 through the gas pipe 14. Ru.
　そのドライポンプ１７の内部構造は、図２及び図３に示している。そのドライポンプ１７では、プロセスチャンバ１１からの使用済みのガスＧ１を、ガス導入口１７ａよりドライポンプ１７の内部に吸引して取り入れ、その使用済みのガスＧ１をドライポンプ１７内部で６段階に徐々に加圧する、すなわち第１段目ポンプ室２２ａ、第２段目ポンプ室２２ｂ、第３段目ポンプ室２２ｃ、第４段目ポンプ室２２ｄ、第５段目ポンプ室２２ｅ、第６段目ポンプ室２２ｆの順に通して、徐々に加圧するようになっている。 The internal structure of the dry pump 17 is shown in FIGS. 2 and 3. In the dry pump 17, the used gas G1 from the process chamber 11 is sucked into the dry pump 17 through the gas inlet 17a, and the used gas G1 is gradually introduced into the dry pump 17 in six stages. That is, the first stage pump chamber 22a, the second stage pump chamber 22b, the third stage pump chamber 22c, the fourth stage pump chamber 22d, the fifth stage pump chamber 22e, and the sixth stage pump. The pressure is gradually increased through the chambers 22f in this order.
　また、図１に示すように、そのドライポンプ１７内で大気圧付近まで加圧された使用済みのガスＧ１は、ガス排出口１７ｂよりガス排気配管１８内に排出され、そのガス排気配管１８から除害装置１９に送られ、その除害装置１９で無害化された後に大気中に排出されるようになっている。したがって、そのガス排気配管１８の一端側はドライポンプ１７のガス排出口１７ｂに接続され、他端側は除害装置１９のガス導入口１９ａに接続されている。 Further, as shown in FIG. 1, the used gas G1 pressurized to near atmospheric pressure in the dry pump 17 is discharged from the gas exhaust port 17b into the gas exhaust pipe 18, and from the gas exhaust pipe 18. It is sent to the abatement device 19, where it is rendered harmless and then discharged into the atmosphere. Therefore, one end of the gas exhaust pipe 18 is connected to the gas exhaust port 17b of the dry pump 17, and the other end is connected to the gas inlet 19a of the abatement device 19.
　また、ドライポンプ１７には、ドライポンプ１７の停止後、例えばドライポンプ１７内に残留するガスや付着した堆積物（主にＳｉＯ２）によって、図２に示すロータ（２４ａ～２４ｆ）がロックしてしまい、ドライポンプ１７の再起動ができなくなったときに、ドライポンプ１７内の温度を通常運転時の温度と略等しい温度（１００℃～１９０℃）まで昇温させることができる高温（例えば、４００℃）の不活性ガスＧ２（ホットＮ２等）を導入する再起動材料供給配管２１ａと、再起動後にクリーニング材料Ｇ４であるＮＦ３プラズマを導入するプラズマ供給配管２１ｂと、が接続されている。 Furthermore, after the dry pump 17 has stopped, the rotor (24a to 24f) shown in FIG. When the dry pump 17 cannot be restarted due to the A restart material supply pipe 21a that introduces an inert gas G2 (hot N2, etc.) at a temperature of 0.degree.
　再起動材料供給配管２１ａは、一端側が第１の不活性ガス導入ユニット２０ａに接続され、他端側が再起動材料導入口１７ｃに開閉弁３１ａを介して接続されている。再起動材料導入口１７ｃは、図２に示すように、複数個(本実施例では６個)のポンプ室２２ａ～２２ｆの中、途中のポンプ室、本実施例では第３段目ポンプ室２２ｃの箇所に対応して、ポンプケーシング２３に設けている。その再起動材料供給配管２１ａからは、開閉弁３１ａの開閉により、第１の不活性ガス導入ユニット２０ａから送られて来る、高温（例えば、４００℃）の不活性ガスＧ２（ホットＮ２等）が、ドライポンプ１７内に導入されるようになっている。開閉弁３１ａの開閉制御は、制御装置１０の制御により行われる。すなわち、開閉弁３１ａが開のときには、高温の不活性ガスＧ２が再起動材料導入口１７ｃよりポンプケーシング２３内に入る。そして、高温の不活性ガスＧ２が再起動材料導入口１７ｃよりポンプケーシング２３内に一定時間（例えば、約２時間）送り込まれると、ポンプケーシング２３内がドライポンプ１７の運転中と略同じ高温の温度となり、ロータ２４ａ～２４ｆの両側面とポンプ室２２ａ～２２ｆの両側内面との間のギャップが拡がり、ロータ２４ａ～２４ｆのロックが解除されて、ドライポンプ１７の運転再起動が可能になる。 One end of the restart material supply pipe 21a is connected to the first inert gas introduction unit 20a, and the other end is connected to the restart material introduction port 17c via an on-off valve 31a. As shown in FIG. 2, the restart material inlet 17c is located in an intermediate pump chamber among a plurality of (six in this embodiment) pump chambers 22a to 22f, or in the third stage pump chamber 22c in this embodiment. It is provided in the pump casing 23 corresponding to the location. From the restart material supply pipe 21a, a high temperature (for example, 400°C) inert gas G2 (hot N2, etc.) is sent from the first inert gas introduction unit 20a by opening and closing the on-off valve 31a. , is adapted to be introduced into the dry pump 17. Opening/closing control of the on-off valve 31a is performed under control of the control device 10. That is, when the on-off valve 31a is open, the high temperature inert gas G2 enters the pump casing 23 through the restart material inlet 17c. Then, when the high-temperature inert gas G2 is fed into the pump casing 23 from the restart material inlet 17c for a certain period of time (for example, about 2 hours), the inside of the pump casing 23 is heated to approximately the same high temperature as when the dry pump 17 is operating. The temperature increases, the gap between both side surfaces of the rotors 24a to 24f and both inner surfaces of the pump chambers 22a to 22f widens, the rotors 24a to 24f are unlocked, and the dry pump 17 can be restarted.
　次に、ドライポンプ１７の運転状態における、ポンプケーシング２３内のクリーニング方法について説明する。
　プラズマ供給配管２１ｂは、図１に示すように、一端側が開閉弁３１ｂ及びガス配管１４を介してポンプケーシング２３のガス導入口１７ａに接続され、他端側はクリーニング材料供給ユニット３０に接続されている。クリーニング材料供給ユニット３０は、ドライポンプ１７の再起動後に開とされる開閉弁３１ｂを介して、ドライポンプ１７内をクリーニングするクリーニング材料Ｇ４であるＮＦ３プラズマ（Ｆラジカル）がガス導入口１７ａを通してポンプケーシング２３内に供給するようになっている。クリーニング材料Ｇ４としては、ＮＦ３プラズマ（Ｆラジカル）の他に、プラズマ（Ｆラジカル）ＨＦ（フッ化水素）、水蒸気、塩化ケイ素等も含まれる。開閉弁３１ｂの開閉制御は、制御装置１０の制御により行われる。すなわち、開閉弁３１ｂが開のときには、クリーニング材料供給ユニット３０からのクリーニング材料Ｇ４が、ガス導入口１７ａを通してポンプケーシング２３内に入るようになっている。 Next, a method of cleaning the inside of the pump casing 23 while the dry pump 17 is in operation will be described.
As shown in FIG. 1, the plasma supply pipe 21b has one end connected to the gas inlet 17a of the pump casing 23 via the on-off valve 31b and the gas pipe 14, and the other end connected to the cleaning material supply unit 30. There is. In the cleaning material supply unit 30, NF3 plasma (F radicals), which is a cleaning material G4 for cleaning the inside of the dry pump 17, is pumped through the gas inlet 17a through an on-off valve 31b that is opened after the dry pump 17 is restarted. It is designed to be supplied into the casing 23. The cleaning material G4 includes, in addition to NF3 plasma (F radicals), plasma (F radicals), HF (hydrogen fluoride), water vapor, silicon chloride, and the like. Opening/closing control of the on-off valve 31b is performed under control of the control device 10. That is, when the on-off valve 31b is open, the cleaning material G4 from the cleaning material supply unit 30 enters the pump casing 23 through the gas inlet 17a.
　なお、クリーニング材料Ｇ４は、ドライポンプ１７が再起動した後に、ポンプケーシング２３内に流される。そして、ＮＦ３プラズマであるクリーニング材料Ｇ４がポンプケーシング２３内に流されると、生成物がプラズマ内のＦラジカルと反応し、ガスとなって放出され、ドライポンプ１７内の堆積物がほぼ消滅する。そして、ガスとなって放出されたドライポンプ１７内の堆積物は、ガス排出口１７ｂからガス排気配管１８内に流し、除害装置１９内に送り込むことができるようになっている。 Note that the cleaning material G4 is flowed into the pump casing 23 after the dry pump 17 is restarted. Then, when the cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23, the product reacts with F radicals in the plasma and is released as a gas, so that the deposits in the dry pump 17 are almost eliminated. Then, the deposits in the dry pump 17 that are released as a gas can flow into the gas exhaust pipe 18 from the gas exhaust port 17b and be fed into the abatement device 19.
　次に、図２及び図３を用いては、ドライポンプ１７の内部構造をさらに説明する。図２及び図３に示すドライポンプ１７は、容積式真空ポンプであり、複数個(本実施例では６個)のポンプ室、すなわち第１段目ポンプ室２２ａ、第２段目ポンプ室２２ｂ、第３段目ポンプ室２２ｃ、第４段目ポンプ室２２ｄ、第５段目ポンプ室２２ｅ、第６段目ポンプ室２２ｆを有するポンプケーシング２３と、該ポンプ室２２ａ～２２ｆ内にそれぞれ配設されるロータ２４ａ、２４ｂ、２４ｃ、２４ｄ、２４ｅ、２４ｆと、これらのロータ２４ａ～２４ｆが一体的に固設され、これらのロータ２４ａ～２４ｆを各々一体に回転させる１対の回転軸２５ａ、２５ｂと、この一対の回転軸２５ａ、２５ｂを同期回転させるための一対のギア２６ａ、２６ｂと、この一対のギア２６ａ、２６ｂを介して回転軸２５ａ、２５ｂを回転させるための回転駆動機構としてのモータ２７と、ポンプケーシング２３に回転軸２５ａ、２５ｂをそれぞれ軸支する軸受２８ａ、２８ａ、２８ｂ、２８ｂと、を有する。 Next, the internal structure of the dry pump 17 will be further explained using FIGS. 2 and 3. The dry pump 17 shown in FIGS. 2 and 3 is a positive displacement vacuum pump, and has a plurality of pump chambers (six in this embodiment), namely, a first stage pump chamber 22a, a second stage pump chamber 22b, A pump casing 23 has a third-stage pump chamber 22c, a fourth-stage pump chamber 22d, a fifth-stage pump chamber 22e, and a sixth-stage pump chamber 22f. rotors 24a, 24b, 24c, 24d, 24e, 24f, and a pair of rotating shafts 25a, 25b, which are integrally fixed to these rotors 24a to 24f and rotate these rotors 24a to 24f, respectively. , a pair of gears 26a, 26b for synchronously rotating the pair of rotating shafts 25a, 25b, and a motor 27 as a rotational drive mechanism for rotating the rotating shafts 25a, 25b via the pair of gears 26a, 26b. The pump casing 23 includes bearings 28a, 28a, 28b, and 28b that respectively support rotating shafts 25a and 25b.
　また、前記ポンプケーシング２３は、図示しないが組立性を考慮して、複数個のステータ２３ａを順に軸方向に積層配置することにより形成されている。さらに、前記ポンプケーシング２３は、図３に示すように、回転軸２５ａ、２５ｂに対して直角に断面された形状が、概略長方形をした状態に形成されている。 Although not shown, the pump casing 23 is formed by sequentially stacking a plurality of stators 23a in the axial direction in consideration of ease of assembly. Furthermore, as shown in FIG. 3, the pump casing 23 has a generally rectangular cross section taken at right angles to the rotating shafts 25a, 25b.
　次に、このように構成された排ガス処理装置の作用を説明する。まず、ドライポンプ１７を作動させる場合、制御装置１０の始動指令によりドライポンプ１７が作動されると、モータ２７も駆動されて、モータ２７により回転軸２５ａが回転する。このとき、回転軸２５ａと平行に配置されている回転軸２５ｂは、ギア２６ａ、２６ｂの噛み合わせにより同期回転するようになっており、回転軸２５ａとは反対向きに回転軸２５ｂが回転する。 Next, the operation of the exhaust gas treatment device configured as described above will be explained. First, when operating the dry pump 17, when the dry pump 17 is operated by a start command from the control device 10, the motor 27 is also driven, and the motor 27 rotates the rotating shaft 25a. At this time, the rotating shaft 25b, which is arranged parallel to the rotating shaft 25a, rotates synchronously with the gears 26a and 26b, and the rotating shaft 25b rotates in the opposite direction to the rotating shaft 25a.
　また、それら回転軸２５ａ、２５ｂの回転により、回転軸２５ａに一体的に固設されたロータ２４ａ～２４ｆと、回転軸２５ｂに一体的に固設されたロータ２４ａ～２４ｆとが、ポンプ室２２ａ～２２ｆ内において、互いに逆回転する。なお、図示していないが、本実施例における回転軸２５ａ、２５ｂにそれぞれ取り付けられているロータ２４ａ～２４ｆは、繭型のルーツロータであり、互いに非接触にて微小な隙間を維持しつつ９０°の位相差をもって同期回転する。 Further, due to the rotation of these rotating shafts 25a and 25b, the rotors 24a to 24f integrally fixed to the rotating shaft 25a and the rotors 24a to 24f integrally fixed to the rotating shaft 25b are rotated into the pump chamber 22a. ~22f, they rotate in opposite directions. Although not shown, the rotors 24a to 24f respectively attached to the rotating shafts 25a and 25b in this embodiment are cocoon-shaped roots rotors, and are rotated at 90° while maintaining a small gap without contacting each other. Rotates synchronously with a phase difference of
　これにより、真空対象空間に連通されるガス導入口１７ａから、第１段目ポンプ室２２ａに使用済みのガスＧ１が吸引される。この後、第１段目ポンプ室２２ａから第２段目ポンプ室２２ｂ、第３段目ポンプ室２２ｃ、第４段目ポンプ室２２ｄ、第５段目ポンプ室２２ｅ、第６段目ポンプ室２２ｆへと順番に使用済みのガスＧ１が吸引されて、最終的に、使用済みのガスＧ１が第６段目ポンプ室２２ｆのガス排出口１７ｂと連通しているガス排気配管１８を介してドライポンプ１７から排出され、真空対象空間が真空状態となる。 As a result, the used gas G1 is sucked into the first stage pump chamber 22a from the gas inlet 17a communicating with the vacuum target space. After this, from the first stage pump chamber 22a to the second stage pump chamber 22b, the third stage pump chamber 22c, the fourth stage pump chamber 22d, the fifth stage pump chamber 22e, and the sixth stage pump chamber 22f. The used gas G1 is sequentially sucked into the dry pump through the gas exhaust pipe 18 communicating with the gas exhaust port 17b of the sixth stage pump chamber 22f. 17, and the vacuum target space becomes a vacuum state.
　このとき、使用済みのガスＧ１はそれぞれのポンプ室２２ａ、２２ｂ、２２ｃ、２２ｄ、２２ｅ、２２ｆにおいて圧縮されながら排出されていくので、使用済みのガスＧ１の温度が上昇するとともに、ポンプケーシング２３の温度も上昇する。なお、ポンプ室２２ａ、２２ｂ、２２ｃ、２２ｄ、２２ｅ、２２ｆのうち、吸入側と吐出側における使用済みのガスＧ１の圧力の差が大きい第６段目ポンプ室２２ｆの吐出側において、最も使用済みのガスＧ１の温度が高くなる。ここでの使用済みのガスＧ１の温度は、例えば１５０～２００℃程度の比較的高い温度とされる。 At this time, the used gas G1 is discharged while being compressed in each of the pump chambers 22a, 22b, 22c, 22d, 22e, and 22f, so the temperature of the used gas G1 increases and the temperature of the pump casing 23 increases. The temperature also rises. Note that among the pump chambers 22a, 22b, 22c, 22d, 22e, and 22f, the used gas G1 is the most used on the discharge side of the sixth stage pump chamber 22f, where the difference in pressure between the suction side and the discharge side is large. The temperature of gas G1 increases. The temperature of the used gas G1 here is relatively high, for example, about 150 to 200°C.
　また、第６段目ポンプ室２２ｆより排出された使用済みのガスＧ１は、ガス排気配管１８を通って数ｍ先にある除害装置１９に向かう。 Additionally, the used gas G1 discharged from the sixth stage pump chamber 22f passes through the gas exhaust pipe 18 and heads to the abatement device 19 located several meters ahead.
　ところで、本実施例のようなドライポンプ１７では、ドライポンプ１７の内部に残留するガスが、膜や粉として固形化されて堆積物（主にＳｉＯ２：シリカ）となり、この堆積物が短期間（２～３ヶ月）でドライポンプの内部に付着し、運転不具合を発生させる。また、メンテナンスやそれ以外の事情でドライポンプ１７を一時的に停止させると、ロータ２４ａ～２４ｆがロックしてしまい再起動が不能になることがある。これは、前述したように、ロータ２４ａ～２４ｆと固定側であるポンプ室２２ａ～２２ｆの内壁面とのギャップを、運転時はポンプ室２２ａ～２２ｆが高温になって、ポンプ室２２ａ～２２ｆが拡がること等を想定して、ポンプ停止時にはロータ２４ａ～２４ｆの両側面とポンプ室２２ａ～２２ｆの両側内面との間のギャップが、片側（左側）が広がり、もう片側（右側）が狭くなるように設計しているためであり、停止時における片側のギャップは数１０～数１００μｍ程度に設計されている。 By the way, in the dry pump 17 like this embodiment, the gas remaining inside the dry pump 17 is solidified as a film or powder and becomes a deposit (mainly SiO2: silica), and this deposit remains for a short period of time ( After 2 to 3 months), it adheres to the inside of the dry pump and causes operational problems. Furthermore, if the dry pump 17 is temporarily stopped for maintenance or other reasons, the rotors 24a to 24f may become locked, making it impossible to restart the pump. As mentioned above, this is because the gap between the rotor 24a to 24f and the inner wall surface of the pump chambers 22a to 22f, which is the fixed side, becomes high during operation. In order to prevent the pump from widening, the gap between both side surfaces of the rotors 24a to 24f and both inner surfaces of the pump chambers 22a to 22f widens on one side (left side) and narrows on the other side (right side) when the pump is stopped. This is because the gap on one side when stopped is designed to be approximately several tens to several hundreds of μm.
　そこで、ドライポンプ１７を停止して、再起動しようとしたときに、ロータ２４ａ～２４ｆとポンプ室２２ａ～２２ｆの内壁面とのギャップが堆積物で詰まり、ロータ２４ａ～２４ｆがロックされてしまった場合には、制御装置１０を介して開閉弁３１ａを開にし、第１の不活性ガス導入ユニット２０ａから略４００℃の高温の不活性ガスＧ２を、再起動材料導入口１７ｃよりポンプケーシング２３内に略数時間（例えば２時間程度）送り込む。ここでは、再起動材料導入口１７ｃは、第４段目ポンプ室２２ｄに設けられていて、略４００℃の高温の不活性ガスＧ２は、第４段目ポンプ室２２ｄからポンプケーシング２３内に導入され、これが第３段目ポンプ室２２ｃ、第２段目ポンプ室２２ｂ、第１段目ポンプ室２２ａ及び第５段目ポンプ室２２ｅ、第６段目ポンプ室２２ｆと、ガス導入口１７ａ側とガス排出口１７ｂ側の両方に向かって広がり、ポンプケーシング２３内の全体を高速、かつ高温に加熱する。この加熱により、ポンプケーシング２３内の温度がドライポンプ１７の運転中と略同じ高温の温度（略１５０℃～２００℃）となり、ロータ２４ａ～２４ｆの両側面とポンプ室２２ａ～２２ｆの両側内面との間のギャップが拡がるとともに堆積物が溶かされ、ロータ２４ａ～２４ｆのロックが解除されてドライポンプ１７の運転再起動が可能になる。すなわち、ここでの処理は、高温の不活性ガスＧ２を導入して、ポンプケーシング２３内の温度をドライポンプ１７の通常運転時の温度と略等しい温度に加熱し、ドライポンプ１７が起動できるようにガス流路を拡張させるステップある。なお、ポンプケーシング２３内に導入された不活性ガスＧ２は、ガス排気配管１８に流され、除害装置１９内に送り込まれる。また、本実施例では、ポンプケーシング２３内に送り込む不活性ガスＧ２の温度は、ポンプケーシング２３内に導入される前の供給管内での温度低下を見越して、略４００℃であり、ポンプケーシング２３を加熱する温度は略１５０℃～２００℃としているが、ポンプケーシング２３内に固化している堆積物が溶け、ロータ２４ａ～２４のロックが解除される温度であれば、これ以外の温度（低い温度でも高い温度）であっても構わない。 Therefore, when the dry pump 17 was stopped and an attempt was made to restart it, the gaps between the rotors 24a to 24f and the inner walls of the pump chambers 22a to 22f were clogged with deposits, and the rotors 24a to 24f were locked. In this case, the on-off valve 31a is opened via the control device 10, and the high-temperature inert gas G2 of about 400° C. is introduced into the pump casing 23 from the restart material inlet 17c from the first inert gas introduction unit 20a. for approximately several hours (for example, about 2 hours). Here, the restart material inlet 17c is provided in the fourth stage pump chamber 22d, and the high temperature inert gas G2 of approximately 400° C. is introduced into the pump casing 23 from the fourth stage pump chamber 22d. This is the third stage pump chamber 22c, the second stage pump chamber 22b, the first stage pump chamber 22a, the fifth stage pump chamber 22e, the sixth stage pump chamber 22f, and the gas inlet 17a side. It spreads toward both sides of the gas discharge port 17b, heating the entire inside of the pump casing 23 to a high speed and high temperature. Due to this heating, the temperature inside the pump casing 23 becomes approximately the same high temperature (approximately 150° C. to 200° C.) as during operation of the dry pump 17, and both side surfaces of the rotors 24a to 24f and both inner surfaces of the pump chambers 22a to 22f are heated. As the gap between them widens, the deposits are melted, and the rotors 24a to 24f are unlocked, allowing the dry pump 17 to restart. That is, in this process, high-temperature inert gas G2 is introduced to heat the inside of the pump casing 23 to a temperature approximately equal to the temperature during normal operation of the dry pump 17, so that the dry pump 17 can be started. There is a step to expand the gas flow path. Note that the inert gas G2 introduced into the pump casing 23 is passed through the gas exhaust pipe 18 and sent into the abatement device 19. Further, in this embodiment, the temperature of the inert gas G2 sent into the pump casing 23 is approximately 400° C. in anticipation of a temperature drop in the supply pipe before being introduced into the pump casing 23. The heating temperature is approximately 150°C to 200°C, but other temperatures (lower temperature or high temperature).
　また、ドライポンプ１７の運転再起動が可能になったら、制御装置１０を介して開閉弁３１ｂを開にし、クリーニング材料供給ユニット３０から、ＮＦ３プラズマ（Ｆラジカル）であるクリーニング材料Ｇ４をガス導入口１７ａからポンプケーシング２３内に送り込み、クリーニング材料Ｇ４をポンプケーシング２３内に流す。ここでのクリーニング処理は、クリーニング材料Ｇ４をガス流路に導入して、堆積物を除去するステップである。また、ポンプケーシング２３内に流されたクリーニング材料Ｇ４は、ガス排出口１７ｂからガス排気配管１８を通して除害装置１９内に流される。そして、ポンプケーシング２３内に送り込まれたクリーニング材料Ｇ４は、ポンプケーシング２３内を流れるとき、生成物がプラズマ内のＦラジカルと反応し、ガスとなって放出され、ドライポンプ１７内の堆積物がほぼ消滅する。また、ガスとなって放出されたドライポンプ１７内の堆積物は、ガス排出口１７ｂからガス排気配管１８内にクリーニング材料Ｇ４と共に流され、さらに除害装置１９内に送り込まれる。 When it becomes possible to restart the operation of the dry pump 17, the on-off valve 31b is opened via the control device 10, and the cleaning material G4, which is NF3 plasma (F radical), is supplied from the cleaning material supply unit 30 to the gas inlet port. 17a into the pump casing 23, and the cleaning material G4 flows into the pump casing 23. The cleaning process here is a step in which the cleaning material G4 is introduced into the gas flow path to remove deposits. Further, the cleaning material G4 flowing into the pump casing 23 is flowed into the abatement device 19 from the gas exhaust port 17b through the gas exhaust pipe 18. When the cleaning material G4 fed into the pump casing 23 flows through the pump casing 23, the product reacts with F radicals in the plasma and is released as a gas, removing deposits in the dry pump 17. Almost disappears. Further, the deposits in the dry pump 17 released as a gas are flowed together with the cleaning material G4 into the gas exhaust pipe 18 from the gas outlet 17b, and are further sent into the abatement device 19.
　図４は、ＮＦ３プラズマであるクリーニング材料Ｇ４をガス導入口１７ａからポンプケーシング２３内に流し、ガス排出口１７ｂから排出される単位時間当たりの、ＮＦ３（三フッ化窒素）プラズマとＳｉＦ４（四フッ化ケイ素）の各濃度（ｐｐｍ）を測定したデータである。なお、図中、縦軸は濃度（ｐｐｍ）、横軸は経過時間Ｔである。 FIG. 4 shows the difference between NF3 (nitrogen trifluoride) plasma and SiF4 (tetrafluoride) plasma per unit time when cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23 from the gas inlet 17a and discharged from the gas outlet 17b. This is data obtained by measuring each concentration (ppm) of silicon oxide). In the figure, the vertical axis is the concentration (ppm), and the horizontal axis is the elapsed time T.
　図４のデータでは、ＮＦ３のプラズマ（Ｆイオン）によって固体のＳｉＯ２（シリカ）が気体のＳｉＦ４に変化し、排出されていく様子を示している。すなわち、図４では、ガス導入口１７ａからポンプケーシング２３内にＮＦ３プラズマを導入して、時間Ｔ０から時間Ｔｎまでにガス導入口１７ａから排出されたＮＦ３プラズマの量（濃度）とＳｉＦ４の量（濃度）の変化を各々表している。図中、時間Ｔ１～Ｔ２の期間におけるＮＦ３プラズマの濃度が低いのはＳｉＯ２との反応が進んでいるためである。また、ＳｉＦ４への変化は、時間Ｔ２の前後がピークで、その後におけるＳｉＦ４への変化は緩やかに減少して行く。したがって、このデータからも、ＮＦ３プラズマであるクリーニング材料Ｇ４をガス導入口１７ａからポンプケーシング２３内に流すと、固体のＳｉＯ２が気体のＳｉＦ４に変化してガス排出口１７ｂから排出され、堆積物であるＳｉＯ２がポンプケーシング２３内から消滅していくことがわかる。 The data in FIG. 4 shows that solid SiO2 (silica) is changed into gaseous SiF4 by NF3 plasma (F ions) and is discharged. That is, in FIG. 4, NF3 plasma is introduced into the pump casing 23 from the gas inlet 17a, and the amount (concentration) of NF3 plasma and the amount of SiF4 (concentration) discharged from the gas inlet 17a from time T0 to time Tn are calculated. Each represents a change in concentration). In the figure, the reason that the concentration of NF3 plasma during the period from time T1 to T2 is low is because the reaction with SiO2 is progressing. Further, the change to SiF4 peaks around time T2, and thereafter the change to SiF4 gradually decreases. Therefore, this data also shows that when the cleaning material G4, which is NF3 plasma, is flowed into the pump casing 23 from the gas inlet 17a, solid SiO2 changes to gaseous SiF4 and is discharged from the gas outlet 17b. It can be seen that some SiO2 disappears from inside the pump casing 23.
　したがって、この実施例による排ガス処理装置によれば、プロセスガスの堆積物が原因でドライポンプ１７のロータ２４ａ～２４ｆの回転がロックされて、ドライポンプ１７が停止した状態から再起動できないとき、ドライポンプ１７のガス流路に、ドライポンプ１７の通常運転時の温度と略等しい温度に昇温するための高温の不活性ガスＧ２を導入して、ドライポンプ１７内の温度を通常運転時に近い温度に戻し、ドライポンプ１７内に付着している堆積物を高温の熱で溶かすと、ロータ２４ａ～２４ｆのロックを解除させてロータ２４ａ～２４ｆが回転できる状態にすることができる。 Therefore, according to the exhaust gas treatment apparatus according to this embodiment, when the rotation of the rotors 24a to 24f of the dry pump 17 is locked due to process gas deposits and the dry pump 17 cannot be restarted from a stopped state, A high-temperature inert gas G2 is introduced into the gas flow path of the pump 17 to raise the temperature to approximately the same as the temperature during normal operation of the dry pump 17, and the temperature inside the dry pump 17 is brought to a temperature close to that during normal operation. When the deposits adhering inside the dry pump 17 are melted with high temperature heat, the locks of the rotors 24a to 24f can be released and the rotors 24a to 24f can be rotated.
　また、ロータ２４ａ～２４ｆが回転できる状態になった後、ガス流路にプロセスガスＧ１と反応するクリーニング材料Ｇ４を導入してガス流路内の堆積物を除去するので、ドライポンプ１７内の堆積物をより速く、かつ綺麗に除去することができる。これにより、メンテナンス等を短時間で綺麗に終えることができる。 In addition, after the rotors 24a to 24f are ready to rotate, the cleaning material G4 that reacts with the process gas G1 is introduced into the gas flow path to remove deposits in the gas flow path. Objects can be removed faster and more cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
　なお、第１の実施例では、再起動材料供給配管２１ａを、複数個のポンプ室２２ａ～２２ｆの中の途中のポンプ室、すなわち第４段目ポンプ室２２ｄに対応しているポンプケーシング２３の箇所に再起動材料導入口１７ｃを設け、ポンプケーシング２３内に高温の不活性ガスＧ２を第３段目ポンプ室２２ｃから導入しているが、これは必ずしも第３段目ポンプ室２２ｃでなくても構わない。例えばガス導入口１７ａから導入して第１段目ポンプ室２２ａから流してもよい。しかし、第１段目ポンプ室２２ａからではなく、途中のポンプ室から導入した場合の効果としては、次のようなことがある。 In the first embodiment, the restart material supply pipe 21a is connected to the pump casing 23 corresponding to the intermediate pump chamber among the plurality of pump chambers 22a to 22f, that is, the fourth stage pump chamber 22d. A restart material inlet 17c is provided at a location, and high-temperature inert gas G2 is introduced into the pump casing 23 from the third-stage pump chamber 22c, but this is not necessarily the third-stage pump chamber 22c. I don't mind. For example, the gas may be introduced from the gas inlet 17a and flowed from the first stage pump chamber 22a. However, the effects of introducing from an intermediate pump chamber instead of from the first stage pump chamber 22a are as follows.
　ポンプケーシング２３内に高温の不活性ガスＧ２を、第１段目ポンプ室２２ａから流した場合と途中の第３段目ポンプ室２２ｃ（又は第４段目ポンプ室２２ｄ）から流した場合とを、実験で比較して見ところ、最終の第６段目ポンプし２２ｆの箇所に到達したときの温度は、第１段目ポンプ室２２ａから流した場合の温度は、途中の第３段目ポンプ室２２ｃから流した場合の温度に比べて著しく低下する。そして、再起動が可能になるまでの時間は、第１段目ポンプ室２２ａから流した場合の方が第３段目ポンプ室２２ｃから流した場合に比べて長いという結果が得られた。これは、途中の第３段目ポンプ室２２ｃからポンプケーシング２３内に高温の不活性ガスＧ２を導入すると、不活性ガスＧ２の温度が第３段目ポンプ室２２ｃから、第２段目ポンプ室２２ｂ、第１段目ポンプ室２２ａへと伝達されると共に、第３段目ポンプ室２２ｃから第４段目ポンプ室２２ｄ、第５段目ポンプ室２２ｅ、第６段目ポンプ室２２ｆの順に、中間の位置から入口側と出口側の両方に伝熱されて広がり、ポンプケーシング２３内の全体を通常運転時の温度と略等しい温度にまで効果的に加熱できたと思われる。したがって、途中の第３段目ポンプ室２２ｃや第４段目ポンプ室２２ｄから流した場合の方が、ポンプケーシング２３内の全体を通常運転時の温度と略等しい温度にまで急速に昇温（加熱）させることができ、再起動できるまでの時間を短縮できることが分かった。 A case in which the high-temperature inert gas G2 is flowed into the pump casing 23 from the first stage pump chamber 22a and a case in which it is flowed from the third stage pump chamber 22c (or fourth stage pump chamber 22d) in the middle. , compared in the experiment, the temperature when the final 6th stage pump reaches the point 22f is the temperature when flowing from the 1st stage pump chamber 22a, and the temperature when the flow reaches the 3rd stage pump midway The temperature is significantly lower than that when flowing from the chamber 22c. The results showed that the time required for restarting to become possible was longer when the pump was flowing from the first stage pump chamber 22a than when it was flowing from the third stage pump chamber 22c. This is because when high-temperature inert gas G2 is introduced into the pump casing 23 from the third-stage pump chamber 22c, the temperature of the inert gas G2 increases from the third-stage pump chamber 22c to the second-stage pump chamber. 22b, the first stage pump chamber 22a, and in this order from the third stage pump chamber 22c to the fourth stage pump chamber 22d, the fifth stage pump chamber 22e, and the sixth stage pump chamber 22f. It seems that the heat was transferred and spread from the intermediate position to both the inlet side and the outlet side, and the entire inside of the pump casing 23 was effectively heated to a temperature substantially equal to the temperature during normal operation. Therefore, when the flow is carried out from the intermediate third-stage pump chamber 22c or fourth-stage pump chamber 22d, the entire inside of the pump casing 23 is rapidly heated to approximately the same temperature as the temperature during normal operation ( It was found that the time it takes to restart can be shortened.
図５及び図６は図１に示した排ガス処理装置におけるドライポンプの第２の実施例を示すもので、図５はそのドライポンプ３２の内部構造を模式的に示す概略側面断面図、図６は図５のＢ－Ｂ線断面図である。 5 and 6 show a second embodiment of the dry pump in the exhaust gas treatment device shown in FIG. 1, and FIG. 5 is a schematic side sectional view schematically showing the internal structure of the dry pump 32, and FIG. is a sectional view taken along line BB in FIG. 5.
　図１乃至３に示したドライポンプ１７では、ポンプケーシング２３の外側から再起動材料導入口１７ｃを通して第３段目ポンプ室２２ｃ内にドライポンプ１７の全体の温度が、運転中と略同じ高温の温度（略１５０℃～２００℃）まで昇温させることができる、高温（略４００℃）の不活性ガスＧ２であるポンプ再起動材料を流していたのに対して、ドライポンプ３２の構成では、ポンプケーシング２３のシール用ガス溝３３ａに設けたシール用ガス流路３３にシール用ガスＧ３を導入するための開閉弁３９と開閉弁４１及び、高温の不活性ガスＧ２を導入するための開閉弁４４を設け、開閉弁３９と開閉弁４１及び開閉弁４４を切り換えてシール部を保護するためのシール用ガスＧ３とポンプケーシング２３内を加熱する高温の不活性ガスＧ２とを流すようにしたものである。したがって、以下の説明では、図２及び図３に示した第１の実施例のドライポンプ１７と同じ構成部材には同じ符号付して説明を省略し、異なる構造の部分についてのみ説明する。 In the dry pump 17 shown in FIGS. 1 to 3, the entire temperature of the dry pump 17 is maintained at approximately the same high temperature as during operation, from the outside of the pump casing 23 through the restart material inlet 17c into the third stage pump chamber 22c. Whereas the pump restart material, which is a high temperature (approximately 400°C) inert gas G2 that can be raised to a temperature (approximately 150°C to 200°C), was flowing, in the dry pump 32 configuration, An on-off valve 39 and an on-off valve 41 for introducing the sealing gas G3 into the sealing gas flow path 33 provided in the sealing gas groove 33a of the pump casing 23, and an on-off valve for introducing the high temperature inert gas G2. 44, and the on-off valve 39, the on-off valve 41, and the on-off valve 44 are switched to flow a sealing gas G3 for protecting the seal portion and a high-temperature inert gas G2 for heating the inside of the pump casing 23. It is. Therefore, in the following description, the same constituent members as those of the dry pump 17 of the first embodiment shown in FIGS. 2 and 3 will be given the same reference numerals, and the description thereof will be omitted, and only the parts with different structures will be described.
　図５及び図６において、軸方向に積層配置されてポンプケーシング２３を構成している複数個の各ステータ２３ａは、対向し合う面にシール用ガス溝３３ａが各ポンプ室２２ｄ～２２ｆの外側を囲むようにして形成されている。シール用ガス溝３３ａは、ポンプケーシング２３を形成する際、各ステータ２３ａが積層配置されて組み立てられると、各ポンプ室２２ｄ～２２ｆを形成する部分では、シール用ガス溝３３ａが対向し合ってシール用ガス流路３３を形成するようになっている。なお、シール用ガス流路３３は、シール用ガス溝３３ａがステータ２３ａの両側面にそれぞれ形成されている場合について説明するが、シール用ガス溝３３ａはステータ２３ａの片面のみに形成されていても構わない。また、ポンプケーシング２３の組立時、各ステータ２３ａとの間には、各ポンプ室２２ａ～２２ｆの気密性を保つために、図６に示すように、各ポンプ室２２ｄ～２２ｆの外側を囲むようにしてＯリング用溝３４内にＯリング３５が密に配設される。また、シール用ガス流路３３には、図６に示すように、シール用ガスＧ３及び高温の不活性ガスＧ２を各ポンプ室２２ｄ～２２ｆに取り込むガス取込口４２が設けられている。 In FIGS. 5 and 6, each of the plurality of stators 23a, which are stacked in the axial direction and constitute the pump casing 23, has sealing gas grooves 33a on opposing surfaces that extend outside the pump chambers 22d to 22f. It is formed so as to surround it. When forming the pump casing 23, when the stators 23a are stacked and assembled, the sealing gas grooves 33a face each other in the parts forming the pump chambers 22d to 22f to form a seal. A gas flow path 33 is formed therein. Note that the sealing gas flow path 33 will be described with reference to the case where the sealing gas grooves 33a are formed on both sides of the stator 23a, but the sealing gas grooves 33a may be formed only on one side of the stator 23a. I do not care. In addition, when assembling the pump casing 23, in order to maintain the airtightness of each pump chamber 22a to 22f, a space surrounding the outside of each pump chamber 22d to 22f is placed between the stator 23a and each stator 23a, as shown in FIG. An O-ring 35 is closely arranged within the O-ring groove 34. Furthermore, as shown in FIG. 6, the sealing gas flow path 33 is provided with a gas intake port 42 for introducing the sealing gas G3 and the high-temperature inert gas G2 into each of the pump chambers 22d to 22f.
　ここでのＯリング３５は、前記使用済みのガスＧ１により腐食するので、本実施例のドライポンプ３２では、その腐食を防止するために、ドライポンプ３２の運転中は、第２の不活性ガス導入ユニット２０ｂからシール用ガスＧ３として、不活性ガスであるＮ２ガスをシール用ガス流路３３に導入している。また、各ポンプ室２２ａ～２２ｆ内の圧力は後段に向かうほど高くなっている。そこで本実施例のドライポンプ３２では、後段側である第４、第５、第６段目の各ポンプ室２２ｄ～２２ｆに、Ｎ２ガスであるシール用ガスＧ３を流す(導入する)。これは、より高圧となるポンプ室２２ｄ～２２ｆで腐食性のある使用済みのガスＧ１が圧縮・濃縮されることで、Ｏリング３５の腐食が進みやすくなってシール低下が進むのを防止し、Ｏリング３５と共にシールに寄与するためである。しかし、シール用ガスＧ３を流すポンプ室は、圧力が最も高くなる最終のポンプ室(第６段目ポンプ室２２ｆ)にだけ流すようにしてもよいし、ポンプケーシング２３内の加熱を考慮し、全てのポンプ室２２ａ～２２ｆに対応させてシール用ガス流路３３を設け、全てのシール用ガス流路３３から全てのポンプ室２２ａ～２２ｆ内に高温の不活性ガスＧ２を流すようにしてもよい。 Since the O-ring 35 here is corroded by the used gas G1, in order to prevent this corrosion, in the dry pump 32 of this embodiment, during operation of the dry pump 32, a second inert gas is used. N2 gas, which is an inert gas, is introduced into the sealing gas channel 33 from the introduction unit 20b as the sealing gas G3. Further, the pressure within each pump chamber 22a to 22f increases toward the latter stage. Therefore, in the dry pump 32 of this embodiment, sealing gas G3, which is N2 gas, is flowed (introduced) into each of the pump chambers 22d to 22f of the fourth, fifth, and sixth stages, which are the latter stages. This is because the corrosive used gas G1 is compressed and concentrated in the pump chambers 22d to 22f, which have a higher pressure, and this prevents the O-ring 35 from becoming more easily corroded and sealing deteriorating. This is because it contributes to sealing together with the O-ring 35. However, the pump chamber through which the sealing gas G3 flows may be configured to flow only to the final pump chamber (sixth stage pump chamber 22f) where the pressure is highest, or in consideration of heating inside the pump casing 23, Even if the sealing gas passages 33 are provided corresponding to all the pump chambers 22a to 22f, and the high temperature inert gas G2 is made to flow from all the sealing gas passages 33 into all the pump chambers 22a to 22f. good.
　そして、この第２の実施例のドライポンプ３２では、第４、第５、第６段目の各ポンプ室２２ｄ～２２ｆを形成する各ステータ２３ａのシール用ガス溝３３ａには、ステータ２３ａの外表面(ポンプケーシング２３の外表面２９)にシール用ガス導入口３６ａを設けたシール用ガス導入管３８のシール用ガス導入口３６ｂと、同じくステータ２３ａの外表面にシール用ガス排出管接続口３７ａを設けたシール用ガス排出口３７ｂとが設けられている。なお、各シール用ガス導入口３６ａには、シール用ガスＧ３が供給されるシール用ガス導入管３８が開閉弁３９を介して各々接続され、各シール用ガス排出管接続口３７ａには、シール用ガスＧ３が排出されるシール用ガス排出管４０が開閉弁４１を介して各々接続されている。また、シール用ガス排出管４０は、希釈用ガス導入部１８ａを介してガス排気配管１８に接続されている。開閉弁３９、４１には、例えばガス流量の調整が可能な開閉弁を用いるとよい。 In the dry pump 32 of this second embodiment, the sealing gas groove 33a of each stator 23a forming the fourth, fifth, and sixth stage pump chambers 22d to 22f has a sealing gas groove 33a located outside the stator 23a. A sealing gas inlet 36b of a sealing gas inlet 38 having a sealing gas inlet 36a on the surface (outer surface 29 of the pump casing 23) and a sealing gas exhaust pipe connecting port 37a on the outer surface of the stator 23a. A sealing gas exhaust port 37b is provided. A sealing gas inlet pipe 38 to which sealing gas G3 is supplied is connected to each sealing gas inlet 36a via an on-off valve 39, and a sealing gas inlet 38 is connected to each sealing gas exhaust pipe connection port 37a. Seal gas discharge pipes 40 through which gas G3 is discharged are connected to each other via on-off valves 41. Further, the sealing gas exhaust pipe 40 is connected to the gas exhaust pipe 18 via the dilution gas introduction section 18a. For the on-off valves 39 and 41, for example, on-off valves that can adjust the gas flow rate may be used.
　また、シール用ガス導入管３８には、ポンプ再起動材料供給配管４３及び開閉弁４４を介して第１の不活性ガス導入ユニット２０ａが接続されている。開閉弁４４の開閉制御は、制御装置１０の制御により行われる。すなわち、不活性ガスＧ２を流すときには、開閉弁３９と開閉弁４１が閉の状態で、開閉弁４４を開にする。すると、第１の不活性ガス導入ユニット２０ａからの高温の不活性ガスＧ２が、ポンプ再起動材料供給配管４３からシール用ガス導入口３６ａを通ってシール用ガス流路３３内に入り、さらにガス取込口４２を通って第４、第５、第６段目の各ポンプ室２２ｄ～２２ｆ内に流れ込む。そして、この高温の不活性ガスＧ２がポンプケーシング２３内の全体に拡がり、ポンプケーシング２３内の昇温を行う。その後、ガス排出口１７ｂを通ってガス排気配管１８内に排出され、ガス排気配管１８を介して除害装置１９へと送られるようになっている。 Furthermore, the first inert gas introduction unit 20a is connected to the sealing gas introduction pipe 38 via a pump restart material supply pipe 43 and an on-off valve 44. Opening/closing control of the on-off valve 44 is performed under control of the control device 10. That is, when flowing the inert gas G2, the on-off valve 39 and the on-off valve 41 are closed, and the on-off valve 44 is opened. Then, the high-temperature inert gas G2 from the first inert gas introduction unit 20a enters the sealing gas passage 33 from the pump restart material supply pipe 43 through the sealing gas introduction port 36a, and further gas It flows through the intake port 42 into each of the fourth, fifth, and sixth stage pump chambers 22d to 22f. Then, this high-temperature inert gas G2 spreads throughout the inside of the pump casing 23, raising the temperature inside the pump casing 23. Thereafter, the gas is discharged into the gas exhaust pipe 18 through the gas discharge port 17b, and sent to the abatement device 19 via the gas exhaust pipe 18.
　したがって、この第２の実施例における排ガス処理装置では、プロセスガスの堆積部が原因でドライポンプ３２のロータ２４ａ～２４ｆがロックされ、ドライポンプ３２が停止した状態から再起動できないとき、シール用ガス流路３３内に流す高温の不活性ガスＧ２でドライポンプ３２内の温度を通常運転時の温度と略等しい温度（１００℃～１９０℃）まで昇温させて、ドライポンプ３２内の温度を通常運転時に近い温度に急速に戻すことができる。そして、ドライポンプ１７内に付着している堆積物を高温の熱で溶かし、ロータ２４ａ～２４ｆのロックを解除してロータ２４ａ～２４ｆが回転できる状態にすることができる。 Therefore, in the exhaust gas treatment apparatus according to the second embodiment, when the rotors 24a to 24f of the dry pump 32 are locked due to the process gas accumulation and the dry pump 32 cannot be restarted from a stopped state, the sealing gas The temperature inside the dry pump 32 is raised to a temperature approximately equal to the temperature during normal operation (100°C to 190°C) using the high-temperature inert gas G2 flowing into the flow path 33, so that the temperature inside the dry pump 32 becomes normal. The temperature can be quickly returned to near operating temperature. Then, the deposits adhering to the interior of the dry pump 17 are melted by high temperature heat, and the locks of the rotors 24a to 24f are released, allowing the rotors 24a to 24f to rotate.
　また、ドライポンプ３２の運転再起動が可能になったら、制御装置１０を介して開閉弁３１ｂを開にし、ＮＦ３プラズマであるクリーニング材料Ｇ４をガス導入口１７ａからポンプケーシング２３内に送り込み、クリーニング材料Ｇ４をポンプケーシング２３内に流す。ポンプケーシング２３内に流されたクリーニング材料Ｇ４は、ガス排出口１７ｂからガス排気配管１８を通して除害装置１９内に流される。そして、ポンプケーシング２３内に送り込まれたクリーニング材料Ｇ４は、ポンプケーシング２３内を流れるとき、生成物がプラズマ内のＦラジカルと反応し、ガスとなって放出され、ドライポンプ１７内の堆積物がほぼ消滅する。 When it becomes possible to restart the operation of the dry pump 32, the on-off valve 31b is opened via the control device 10, and the cleaning material G4, which is NF3 plasma, is sent into the pump casing 23 from the gas inlet 17a. G4 flows into the pump casing 23. The cleaning material G4 that has flowed into the pump casing 23 is flown into the abatement device 19 from the gas exhaust port 17b through the gas exhaust pipe 18. When the cleaning material G4 fed into the pump casing 23 flows through the pump casing 23, the product reacts with F radicals in the plasma and is released as a gas, removing deposits in the dry pump 17. Almost disappears.
　また、ガスとなって放出されたドライポンプ１７内の堆積物は、ガス排出口１７ｂからガス排気配管１８内にクリーニング材料Ｇ４と共に流され、さらに除害装置１９内に送り込まれる。 Further, the deposits in the dry pump 17 released as a gas are flowed into the gas exhaust pipe 18 from the gas outlet 17b together with the cleaning material G4, and further sent into the abatement device 19.
　したがって、この実施例による排ガス処理装置によれば、プロセスガスの堆積部が原因でドライポンプ３２のロータ２４ａ～２４ｆがロックされ、ドライポンプ１７が停止した状態から再起動できないとき、シール用ガス流路３３内に高温の不活性ガスＧ２を流してドライポンプ１７内の温度を通常運転時に近い温度に戻すので、ドライポンプ３２内の堆積物をより速く、かつ綺麗に除去することができる。これにより、メンテナンス等を短時間で綺麗に終えることができる。 Therefore, according to the exhaust gas treatment apparatus according to this embodiment, when the rotors 24a to 24f of the dry pump 32 are locked due to the process gas accumulation and the dry pump 17 cannot be restarted from a stopped state, the sealing gas flow Since the high temperature inert gas G2 is flowed into the passage 33 to return the temperature inside the dry pump 17 to a temperature close to that during normal operation, the deposits inside the dry pump 32 can be removed more quickly and cleanly. Thereby, maintenance etc. can be completed neatly in a short time.
　なお、第１の実施例の構造と第２の実施例の構造は、必要に応じて組み合わせることもできる。 Note that the structure of the first embodiment and the structure of the second embodiment can be combined as necessary.
　また、各実施例では、ドライポンプ１７及びドライポンプ３２のロータ２４ａ～２４ｆがロックされ、ドライポンプ１７が停止した状態から再起動できないとき、ドライポンプ１７のガス流路に、ドライポンプ１７の通常運転時の温度と略等しい温度まで昇温させるための高温の不活性ガスＧ２を流してドライポンプ１７内の温度を通常運転時に近い温度に戻し、再起動したその後からドライポンプ１７内にクリーニング材料Ｇ４を流して堆積物を消滅するようにした。しかし、ドライポンプ１７及びドライポンプ３２の停止前に、予めドライポンプ１７及びドライポンプ３２のガス流路にプロセスガスと反応するクリーニング材料Ｇ４を流し、プロセスガスＧ１による堆積物（ＳｉＯ２）を除去するようすることも可能である。 Further, in each embodiment, when the dry pump 17 and the rotors 24a to 24f of the dry pump 32 are locked and the dry pump 17 cannot be restarted from a stopped state, a normal The temperature inside the dry pump 17 is returned to a temperature close to that during normal operation by flowing a high-temperature inert gas G2 to raise the temperature to approximately the same as the temperature during operation, and after restarting the dry pump 17, cleaning material is added to the inside of the dry pump 17. I flushed G4 to eliminate the deposits. However, before stopping the dry pump 17 and the dry pump 32, a cleaning material G4 that reacts with the process gas is flowed into the gas flow paths of the dry pump 17 and the dry pump 32 in advance to remove deposits (SiO2) caused by the process gas G1. It is also possible to do this.
　ドライポンプ１７及びドライポンプ３２の停止前に、ドライポンプ１７及びドライポンプ３２のガス流路にプロセスガスと反応するクリーニング材料Ｇ４を流し、プロセスガスによる堆積物（ＳｉＯ２）を除去する一例を、図７を用いて図１乃至図３に示したドライポンプ１７の場合について説明する。 An example of removing deposits (SiO2) caused by the process gas by flowing a cleaning material G4 that reacts with the process gas into the gas flow paths of the dry pump 17 and the dry pump 32 before stopping the dry pump 17 and the dry pump 32 is shown in FIG. 7 will be used to explain the case of the dry pump 17 shown in FIGS. 1 to 3.
　図７に示す一例では、制御装置１０により制御する場合である。制御装置１０には、ドライポンプ１７の運転中に、ブースターポンプのスピード１０１とドライポンプ１７のスピード１０２及びドライポンプ１７の電流値１０３とがそれぞれ入力され、これらの各値を約１時間監視する。この１時間の間にドライポンプ１７のスピード１０２がブースターポンプのスピード１０１を数回下回り、また、ドライポンプ１７の電流値１０３が閾値（例えば、４５．０アンペア）を数回超えた場合には、制御装置１０がドライポンプ１７内に堆積物が基準以上堆積されていると判断する。そして、制御装置１０は、ドライポンプ１７の停止前に、第１の不活性ガス導入ユニット２０ａ及び開閉弁３１ｂを制御して、ガス導入口１７ａからポンプケーシング２３内にプロセスガスＧ１と反応するクリーニング材料Ｇ４を一定時間流し、ポンプケーシング２３内に堆積している堆積物を消滅させる。これにより、ドライポンプ１７を停止させることなく、ドライポンプ１７内に付着している堆積物を事前に除去することができる。 An example shown in FIG. 7 is a case where control is performed by the control device 10. While the dry pump 17 is in operation, the speed 101 of the booster pump, the speed 102 of the dry pump 17, and the current value 103 of the dry pump 17 are respectively input to the control device 10, and these values are monitored for approximately one hour. . If the speed 102 of the dry pump 17 falls below the speed 101 of the booster pump several times during this one hour period, and the current value 103 of the dry pump 17 exceeds the threshold value (for example, 45.0 amperes) several times, , the control device 10 determines that the amount of deposits in the dry pump 17 exceeds the standard. Then, before the dry pump 17 is stopped, the control device 10 controls the first inert gas introduction unit 20a and the on-off valve 31b to cause cleaning to react with the process gas G1 from the gas introduction port 17a into the pump casing 23. The material G4 is allowed to flow for a certain period of time to eliminate the deposits that have accumulated inside the pump casing 23. Thereby, deposits adhering to the inside of the dry pump 17 can be removed in advance without stopping the dry pump 17.
　なお、本発明は、本発明の精神を逸脱しない限り種々の改変や組み合わせを成すことができ、そして、本発明が該改変や組み合わせされたものに及ぶことは当然である。 Note that the present invention can be made in various modifications and combinations without departing from the spirit of the invention, and it goes without saying that the present invention extends to such modifications and combinations.
１０　　：制御装置
１１　　：プロセスチャンバ
１２　　：半導体ウエハ
１３　　：ガス供給配管
１７　　：ドライポンプ
１７ａ　：ガス導入口
１７ｂ　：ガス排出口
１７ｃ　：再起動材料導入口
１８　　：ガス排気配管
１９　　：除害装置
２０ａ　：第１の不活性ガス導入ユニット
２０ｂ　：第２の不活性ガス導入ユニット
２１ａ　：再起動材料供給配管
２１ｂ　：プラズマ供給配管
２２ａ　：第１段目ポンプ室
２２ｂ　：第２段目ポンプ室
２２ｃ　：第３段目ポンプ室
２２ｄ　：第４段目ポンプ室
２２ｅ　：第５段目ポンプ室
２２ｆ　：第６段目ポンプ室
２３　　：ポンプケーシング
２４ａ　：ロータ
２４ｂ　：ロータ
２４ｃ　：ロータ
２４ｄ　：ロータ
２４ｅ　：ロータ
２４ｆ　：ロータ
３１ａ　：開閉弁
３１ｂ　：開閉弁
３２　　：ドライポンプ
３３　　：シール用ガス流路
３３ａ　：シール用ガス溝
３６　　：シール用ガス導入通路
３６ａ　：シール用ガス導入口
３６ｂ　：シール用ガス導入口
３７　　：シール用ガス排出通路
３７ａ　：シール用ガス排出管接続口
３７ｂ　：シール用ガス排出口
３８　　：シール用ガス導入管
３９　　：開閉弁
４０　　：シール用ガス排出管
４１　　：開閉弁
４２　　：ガス取込口
４３　　：ポンプ再起動材料供給配管
４４　　：開閉弁
Ｇ１　　：プロセスガス
Ｇ２　　：不活性ガス
Ｇ３　　：シール用ガス
Ｇ４　　：クリーニング材料
  10: Control device 11: Process chamber 12: Semiconductor wafer 13: Gas supply piping 17: Dry pump 17a: Gas inlet 17b: Gas outlet 17c: Restart material inlet 18: Gas exhaust piping 19: Abatement device 20a: First inert gas introduction unit 20b: Second inert gas introduction unit 21a: Restart material supply piping 21b: Plasma supply piping 22a: First stage pump chamber 22b: Second stage pump chamber 22c: Third Stage pump chamber 22d : Fourth stage pump chamber 22e : Fifth stage pump chamber 22f : Sixth stage pump chamber 23 : Pump casing 24a : Rotor 24b : Rotor 24c : Rotor 24d : Rotor 24e : Rotor 24f : Rotor 31a: On-off valve 31b: On-off valve 32: Dry pump 33: Seal gas passage 33a: Seal gas groove 36: Seal gas introduction passage 36a: Seal gas introduction port 36b: Seal gas introduction port 37: For seal Gas exhaust passage 37a: Seal gas discharge pipe connection port 37b: Seal gas discharge port 38: Seal gas introduction pipe 39: Open/close valve 40: Sealing gas discharge pipe 41: Open/close valve 42: Gas intake port 43: Pump Restart material supply piping 44: Open/close valve G1: Process gas G2: Inert gas G3: Seal gas G4: Cleaning material

Claims (6)

  1. 　凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプと、
    　前記プロセスガスの堆積物が堆積し、停止状態の前記真空ポンプのガス流路に、前記真空ポンプの通常運転時の温度と略等しい温度に昇温するための高温の不活性ガスを導入して、前記真空ポンプが起動できるように前記ガス流路を拡張させる第１の不活性ガス導入ユニットと、
    　クリーニング材料を前記ガス流路に導入して、前記堆積物を除去するクリーニング材料導入ユニットと、
    を備えていることを特徴とする真空排気システム。     a vacuum pump for evacuating process gases containing condensable gases or oxidized dust;
    Introducing a high-temperature inert gas into the gas flow path of the vacuum pump in a stopped state, where deposits of the process gas have accumulated, to raise the temperature to approximately the same temperature as the temperature during normal operation of the vacuum pump. , a first inert gas introduction unit that expands the gas flow path so that the vacuum pump can be started;
    a cleaning material introduction unit that introduces a cleaning material into the gas flow path to remove the deposits;
    A vacuum exhaust system characterized by being equipped with.
  2. 　前記第１の不活性ガス導入ユニットは、前記ガス流路の略中間に前記不活性ガスを導入することを特徴とする請求項１に記載の真空排気システム。 The evacuation system according to claim 1, wherein the first inert gas introduction unit introduces the inert gas approximately in the middle of the gas flow path.
  3. 　前記真空ポンプのシール部を保護するために不活性ガスを前記ガス流路に導入する第２の不活性ガス導入ユニットをさらに備え、
    　前記第１の不活性ガス導入ユニットが前記不活性ガスを導入する位置と前記第２の不活性ガス導入ユニットが前記ガス流路に導入する位置は、同一であることを特徴とする請求項１または２に記載の真空排気システム。     further comprising a second inert gas introduction unit that introduces an inert gas into the gas flow path to protect the seal portion of the vacuum pump,
    Claim 1, wherein the position where the first inert gas introduction unit introduces the inert gas and the position where the second inert gas introduction unit introduces the inert gas into the gas flow path are the same. Or the vacuum exhaust system described in 2.
  4. 　前記真空ポンプは、容積式真空ポンプであることを特徴とする請求項１から３のいずれか１項に記載の真空ポンプ。 The vacuum pump according to any one of claims 1 to 3, wherein the vacuum pump is a positive displacement vacuum pump.
  5. 　凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプのクリーニング方法であって、
    　前記プロセスガスの堆積物が堆積し、停止状態の前記真空ポンプのガス流路に、前記真空ポンプの通常運転時の温度と略等しい温度に昇温するための高温の不活性ガスを導入して、前記真空ポンプが起動できるように前記ガス流路を拡張させるステップと、
    　クリーニング材料を前記ガス流路に導入して、前記堆積物を除去するステップと、
    を含むことを特徴とする真空ポンプのクリーニング方法。     A method for cleaning a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, the method comprising:
    Introducing a high-temperature inert gas into the gas flow path of the vacuum pump in a stopped state, where deposits of the process gas have accumulated, to raise the temperature to approximately the same temperature as the temperature during normal operation of the vacuum pump. , expanding the gas flow path so that the vacuum pump can be activated;
    introducing a cleaning material into the gas flow path to remove the deposits;
    A method for cleaning a vacuum pump, comprising:
  6. 　凝縮性ガス又は酸化粉塵を含むプロセスガスを排気する真空ポンプのクリーニング方法であって、
    　前記真空ポンプの停止前に、前記真空ポンプ内のガス流路にクリーニング材料を導入し、前記プロセスガスによる堆積物を除去するステップを含むことを特徴とする真空ポンプのクリーニング方法。      A method for cleaning a vacuum pump that exhausts a process gas containing condensable gas or oxidized dust, the method comprising:
    A method for cleaning a vacuum pump, comprising the step of introducing a cleaning material into a gas flow path in the vacuum pump to remove deposits caused by the process gas before stopping the vacuum pump.
PCT/JP2023/011783 2022-03-25 2023-03-24 Evacuation system, vacuum pump, and method of cleaning vacuum pump WO2023182489A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1073088A (en) * 1996-08-30 1998-03-17 Hitachi Ltd Turbo vacuum pump and operation system therefor
JP2008248754A (en) * 2007-03-29 2008-10-16 Tokyo Electron Ltd Turbo-molecular pump, substrate process device, and deposit adhesion inhibition method for turbo-molecular pump
JP2016033364A (en) * 2014-07-31 2016-03-10 エドワーズ株式会社 Dry pump and exhaust gas treatment method
JP2017089462A (en) * 2015-11-06 2017-05-25 エドワーズ株式会社 Determination system of vacuum pump and vacuum pump

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1073088A (en) * 1996-08-30 1998-03-17 Hitachi Ltd Turbo vacuum pump and operation system therefor
JP2008248754A (en) * 2007-03-29 2008-10-16 Tokyo Electron Ltd Turbo-molecular pump, substrate process device, and deposit adhesion inhibition method for turbo-molecular pump
JP2016033364A (en) * 2014-07-31 2016-03-10 エドワーズ株式会社 Dry pump and exhaust gas treatment method
JP2017089462A (en) * 2015-11-06 2017-05-25 エドワーズ株式会社 Determination system of vacuum pump and vacuum pump

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