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EP-4737732-A1 - VACUUM EXHAUST SYSTEM AND VACUUM PUMP

EP4737732A1EP 4737732 A1EP4737732 A1EP 4737732A1EP-4737732-A1

Abstract

Provided is a vacuum exhaust system with which reductions in cost and size and/or an increase in the degree of freedom pertaining to piping design can be achieved. A vacuum exhaust system 10 for exhausting a process gas from a plurality of chambers 10-1 to 10-n includes a plurality of turbo molecular pumps 100-1 to 100-n, a collecting pipe 14 to which outlet ports of the plurality of turbo molecular pumps are connected in parallel, one or more dry pumps 16 connected to the collecting pipe 14, and chamber introduction valve devices 30-1 to 30-n for controlling a flow rate of a gas introduced into the plurality of chambers 10-1 to 10-n, wherein an exhaust flow rate threshold T of the process gas is set on the basis of a flow rate that can be exhausted by the plurality of turbo molecular pumps 100-1 to 100-n, and at least one of an introduction timing and the flow rate of the gas is controlled by the chamber introduction valve devices 30-1 to 30-n so as not to exceed the exhaust flow rate threshold T.

Inventors

  • SAKAGUCHI, YOSHIYUKI

Assignees

  • Edwards Japan Limited

Dates

Publication Date
20260506
Application Date
20240624

Claims (9)

  1. A vacuum exhaust system for exhausting a processing gas from a plurality of processing chambers, the vacuum exhaust system comprising: a plurality of first vacuum pumps; a collecting pipe to which outlet ports of the plurality of first vacuum pumps are connected in parallel; one or more second vacuum pumps connected to the collecting pipe; and a gas introduction amount control means for controlling a flow rate of a gas introduced into the plurality of processing chambers, wherein an exhaust flow rate threshold of the processing gas is set on the basis of a flow rate that can be exhausted by the plurality of first vacuum pumps, and at least one of an introduction timing and the flow rate of the gas is controlled by the gas introduction amount control means so as not to exceed the exhaust flow rate threshold.
  2. The vacuum exhaust system according to claim 1, further comprising: a first vacuum pump state information acquiring means for acquiring first vacuum pump state information, which is information indicating states of the plurality of first vacuum pumps, wherein the exhaust flow rate threshold is adjusted in accordance with the first vacuum pump state information.
  3. The vacuum exhaust system according to claim 2, wherein the first vacuum pump state information includes information indicating a pressure state in an interior of the first vacuum pump.
  4. The vacuum exhaust system according to claim 1, further comprising: a pressure adjustment valve disposed on an upstream side of the plurality of first vacuum pumps in order to adjust pressure of the plurality of processing chambers; and a valve signal acquiring means for acquiring state information about the pressure adjustment valve, wherein the exhaust flow rate threshold is adjusted in accordance with a signal from the valve signal acquiring means.
  5. The vacuum exhaust system according to claim 1, further comprising: a second pressure signal acquiring means for acquiring pressure information relating to an interior of the collecting pipe, wherein the exhaust flow rate threshold is adjusted in accordance with a signal from the second pressure signal acquiring means.
  6. The vacuum exhaust system according to any one of claims 1 to 5, wherein an alarm is output to outside when the exhaust flow rate threshold is exceeded.
  7. The vacuum exhaust system according to any one of claims 1 to 5, wherein an alarm is output to outside when an amount of reduction in the adjusted exhaust flow rate threshold reaches a predetermined amount.
  8. The vacuum exhaust system according to any one of claims 1 to 5, further comprising: a gas introduction amount acquiring means for acquiring an introduction amount of the gas introduced into the plurality of processing chambers, wherein at least one of the introduction timing and the flow rate of the gas is controlled by the gas introduction amount control means so that the introduction amount of the gas, acquired by the gas introduction amount acquiring means, does not exceed the exhaust flow rate threshold.
  9. A vacuum pump used in a vacuum exhaust system for exhausting a processing gas from a plurality of processing chambers, the vacuum exhaust system comprising: a plurality of first vacuum pumps; a collecting pipe to which outlet ports of the plurality of first vacuum pumps are connected in parallel; one or more second vacuum pumps connected to the collecting pipe; and a gas introduction amount control means for controlling a flow rate of a gas introduced into the plurality of processing chambers, wherein an exhaust flow rate threshold of the processing gas is set on the basis of a flow rate that can be exhausted by the plurality of first vacuum pumps, at least one of an introduction timing and the flow rate of the gas is controlled by the gas introduction amount control means so as not to exceed the exhaust flow rate threshold, and the vacuum pump is used as the first vacuum pumps provided in the vacuum exhaust system.

Description

[Technical Field] The present invention relates to a vacuum exhaust system including a vacuum pump such as a turbo molecular pump, for example, and a vacuum pump used in the vacuum exhaust system. [Background Art] A turbo molecular pump is generally known as a type of vacuum pump. In the turbo molecular pump, gas (process gas) that has been sucked into a pump main body is exhausted by applying a current to a motor in the pump main body in order to rotate rotor blades, whereby gas molecules of the gas are flicked away. This type of turbo molecular pump may also include a heater and a cooling pipe in order to manage an internal temperature of the pump appropriately. Furthermore, in a vacuum exhaust system relating to a device for manufacturing a semiconductor, a flat panel, or the like (referred to hereinafter as a "semiconductor or the like"), as illustrated in Fig. 1 of PTL 1, cited below, for example, a plurality of turbo molecular pumps (TMPs) may be provided. Here, as disclosed in PTL 1, a type of system in which a single back pump (also known as a BP or a "dry pump") is disposed for the plurality of turbo molecular pumps is known as a central exhaust-type vacuum exhaust system (a central exhaust system). [Citation List] [Patent Literature] [PTL 1] Japanese Patent Application Publication No. 2015-227618 [Summary of Invention] [Technical Problem] A typical turbo molecular pump is dependent on back pressure (secondary-side pressure) (known as back pressure dependency), and when the back pressure takes a certain value (an allowable back pressure) or more, intake pressure (inlet port pressure) cannot be maintained. Likewise in the central exhaust system described above, the back pressure of the turbo molecular pump has to be held at or below the allowable back pressure. However, a maximum flow rate of a gas used in the central exhaust system is assumed by multiplying the number of process chambers (also referred to as "processing chambers", "vacuum chambers", and so on) used to manufacture the semiconductor or the like by a maximum flow rate per process chamber. In other words, when the maximum flow rate per process chamber is set as Qmax and the number of process chambers is set as n, the maximum flow rate of the gas is calculated as Qmax × n. In order to reduce the back pressure of the turbo molecular pump to or below the allowable back pressure, therefore, it is necessary to increase the size (increase an exhaust speed) of the back pump (the dry pump), use piping with low conductance, or employ a turbo molecular pump that exhibits superior back pressure dependency, and as a result, the cost of the exhaust system is likely to increase. An object of the present invention is to provide a vacuum exhaust system with which reductions in cost and size and/or an increase in the degree of freedom pertaining to piping design can be achieved, and a vacuum pump used in the vacuum exhaust system. [Solution to Problem] (1) To achieve the object described above, a vacuum exhaust system according to the present invention is a vacuum exhaust system for exhausting a processing gas from a plurality of processing chambers, the vacuum exhaust system including: a plurality of first vacuum pumps;a collecting pipe to which outlet ports of the plurality of first vacuum pumps are connected in parallel;one or more second vacuum pumps connected to the collecting pipe; anda gas introduction amount control means for controlling a flow rate of a gas introduced into the plurality of processing chambers, whereinan exhaust flow rate threshold of the processing gas is set on the basis of a flow rate that can be exhausted by the plurality of first vacuum pumps, andat least one of an introduction timing and the flow rate of the gas is controlled by the gas introduction amount control means so as not to exceed the exhaust flow rate threshold.(2) Further, to achieve the object described above, a vacuum pump according to the present invention is used as the first vacuum pumps provided in the vacuum exhaust system. [Advantageous Effects of Invention] According to the inventions described above, it is possible to provide a vacuum exhaust system with which reductions in cost and size and/or an increase in the degree of freedom pertaining to the piping design can be achieved, and a vacuum pump used in the vacuum exhaust system. [Brief Description of Drawings] [Fig. 1] Fig. 1 is a schematic illustrative view showing configurations of a vacuum pump and a vacuum exhaust system according to a first embodiment of the present invention.[Fig. 2] Fig. 2 is a circuit diagram of an amplifier circuit.[Fig. 3] Fig. 3 is a time chart showing control performed when a current command value is larger than a detection value.[Fig. 4] Fig. 4 is a time chart showing control performed when the current command value is smaller than the detection value.[Fig. 5] Fig. 5(a) is a schematic illustrative view showing a central exhaust-type vacuum exhaust system according to an