JP2008261886A - Thermal desorption spectroscopy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively analyze a gas having passed through a heating chamber with an article arranged therein. <P>SOLUTION: In this thermal desorption spectroscopy of analyzing a gas having passed through a heating chamber 174 with an article 173 arranged therein, the gas having passed through the heating chamber 174 is introduced into a discharge chamber with two electrodes for applying a voltage therebetween arranged therein, a signal according to a discharge condition between the two electrodes is obtained, and a desorption gas is analyzed based on the signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a temperature-programmed desorption gas analysis method for analyzing a gas flowing through a heating chamber in which articles are arranged.

  2. Description of the Related Art Conventionally, in measurement of high purity gas used in a semiconductor manufacturing process, a technique for measuring the impurity concentration of a measurement gas by a change in discharge between two electrodes to which a voltage is applied has been provided (Patent Documents 1 to 3 below). 7). Thus, conventionally, it has been considered that the change in discharge between two electrodes to which a voltage is applied should be used only for measuring the impurity concentration of the measurement gas.

Conventionally, the measurement technique using such a discharge phenomenon is merely a measurement of the impurity concentration of the measurement gas, and no application technique utilizing the characteristics has been provided.
Japanese Patent Laid-Open No. 9-22680 JP-A-9-61402 Japanese Patent Laid-Open No. 9-166777 JP-A-9-243603 Japanese Patent Laid-Open No. 9-243604 JP-A-6-281624 JP-A-6-317561

  As a result of the research, the inventor has not only changed the impurity concentration in the gas but also changed other atmospheres (for example, pressure change, temperature change, fine particle amount change, charged particle change, electromagnetic wave change). It was found that the state of discharge between the electrodes changed and the sensitivity was very high.

  An object of the present invention is to provide an atmosphere change detection method capable of detecting with high sensitivity that any of a plurality of types of changes has occurred in an atmosphere based on such knowledge. .

  Another object of the present invention is to provide various applied techniques using a measurement technique using a discharge phenomenon.

  Here, the following aspects are presented as technical means for solving the problems. The following eleventh and twelfth aspects correspond to the inventions according to claims 1 and 2.

  The atmosphere change detection method according to the first aspect detects that a change of a plurality of types of changes has occurred in the atmosphere due to a change in discharge between two electrodes to which a voltage is applied. The atmosphere may be, for example, a gas flowing through a flow path or a certain indoor gas that is not flowing. Examples of the change in discharge include a change in potential difference, a change in value obtained by dividing the discharge voltage value by the discharge current value, and a change in value obtained by dividing the discharge voltage value by the integrated value of the discharge current value and the distance between the electrodes. Can be mentioned. This point is the same also about the aspect mentioned later.

  According to the first aspect, as can be understood from the above-described knowledge, it is possible to detect with high sensitivity that some change among a plurality of types of changes has occurred in the atmosphere. Therefore, this detection method is, for example, a method for detecting an abnormality in the gas flowing through the flow path, a method for detecting that a person has entered the room for crime prevention, or a method for detecting when a gas is burning. It can be used as a method for detecting the occurrence of complete combustion or in the second and third modes described later.

  A gas analyzer according to a second aspect includes a plurality of gas analyzers that perform different types of analysis in a gas analyzer that performs a plurality of types of analysis on gases that flow through a plurality of flow paths, respectively, A plurality of gas change detection devices provided respectively corresponding to the gases flowing through the flow paths and detecting changes in the gas, each of which has a discharge chamber through which the gas introduced from the introduction port flows; A plurality of gas change detectors that have two electrodes disposed in a discharge chamber and to which a voltage is applied, and that detect a change in the introduced gas by a change in discharge between the two electrodes; and the plurality of gases And a switching means for selectively connecting the gas flow path in which the change is detected by the change detection device to the plurality of gas analyzers. If it is not detected by the plurality of gas change detection devices that any of the gases has changed, the plurality of gas analyzers may not be operated, or each of the plurality of flow paths may be It is also possible to sequentially connect to the plurality of gas analyzers in a cyclic manner, and sequentially analyze the gas flowing through each flow path by the plurality of gas analyzers.

  According to the second aspect, a change in gas in each flow path is detected by each gas change detection device, and the gas from which the change is detected is selectively selected by a plurality of gas analyzers that perform different types of analysis. Will be analyzed. Since a change in gas means that an abnormality or the like has occurred in the gas, the abnormality or the like of the gas in each flow path is monitored by each gas change detection device. Analysis is performed by a plurality of gas analyzers that perform analysis. Therefore, according to the second aspect, the gas in each flow path is not analyzed by the gas analyzer at the same time. However, since the gas having an abnormality is analyzed by the gas analyzer, there is no problem. Absent.

  By the way, in a semiconductor manufacturing plant or the like, a conventional gas analyzer that performs a plurality of types of analysis for gases flowing through a plurality of flow paths, respectively, includes a set of a plurality of gas analyzers that perform different types of analysis. The set was provided in each of the plurality of flow paths. That is, in this conventional gas analyzer, the same number of gas analyzers that perform the same type of analysis are provided. Therefore, since the plurality of gas analyzers are expensive, such as a particle counter or an atmospheric pressure mass spectrometer (APIMS), the conventional gas analyzer is extremely expensive.

  On the other hand, according to the second aspect, since a set of gas analyzers for performing different types of analysis on the gases flowing through the plurality of flow paths may be provided, the number of gas analyzers Can be greatly reduced. Further, the gas change detection device has two electrodes that are arranged in the discharge chamber and to which a voltage is applied, and detects a change in the introduced gas by a change in discharge between the two electrodes. Despite being able to detect a change in gas with high sensitivity, it is considerably less expensive than an ordinary gas analyzer. Therefore, the gas analyzer according to the second aspect can significantly reduce the cost as compared with the conventional gas analyzer.

  A gas analysis method according to a third aspect is a gas analysis method in which a plurality of types of analysis are performed on gases respectively flowing through a plurality of flow paths, and a voltage is applied to the gases flowing through the plurality of flow paths. Introduced into corresponding discharge chambers in which two electrodes are arranged, detected changes in the introduced gas by changes in discharge between the two electrodes in each discharge chamber, and the detected gases are different from each other. The analysis is selectively performed by a plurality of gas analyzers that perform types of analysis.

  The gas analysis method according to the third aspect corresponds to the gas analysis apparatus according to the second aspect, and can greatly reduce the cost as compared with the conventional gas analysis method.

  An atmosphere detection method according to a fourth aspect is an atmosphere detection method for detecting that a change has occurred in an atmosphere due to a change in discharge between two electrodes to which a voltage is applied, or a characteristic value of the atmosphere. A voltage is intermittently applied between the two electrodes. Examples of the characteristic value include impurity concentration.

  When voltage is constantly applied between the two electrodes, the progress of the electrode deterioration is rapid. However, if the voltage is intermittently applied as in the fourth aspect, the progress of the electrode deterioration is delayed and the life thereof is extended. Can do.

  According to a fifth aspect of the present invention, there is provided a method for monitoring the life of a gas purifier, wherein a gas that has flowed through the gas purifier completely or partway is introduced into a discharge chamber in which two electrodes to which a voltage is applied are arranged. A signal corresponding to the discharge state is obtained, and the life of the gas purifier is monitored based on the signal.

  When the gas purifier approaches or reaches the end of its life, the degree of gas purification decreases and the impurity concentration increases, so the state of discharge between the two electrodes changes. Therefore, in the fifth aspect, a signal corresponding to the state of discharge between the two electrodes can be obtained, and the life of the gas purifier can be monitored based on the signal. The elements of gas purifiers, etc., will end their lifetime when the rupture area (area that has lost the ability to remove impurities) gradually expands from the gas inlet side to the gas outlet side. . For this reason, it is preferable to introduce the gas in the middle of the gas purifier into the discharge chamber, so that it can be surely known that the life of the gas purifier is close before the life of the gas purifier is exhausted.

  By the way, conventionally, there is no method for monitoring the life of the gas purifier, and the gas purifier is periodically replaced. For this reason, if the life of the gas purifier is exhausted by the replacement time, the gas cannot be sufficiently purified, and there is a possibility of seriously affecting the subsequent semiconductor manufacturing process and the like. In order to avoid this, if the gas purifier is replaced at an early stage, the gas purifier has to be replaced even though the deterioration of the gas purifier has hardly progressed and is still fully usable. It was an economy.

  On the other hand, according to the fifth aspect, since it is possible to know that the life of the gas purifier has been approached or reached, the gas purifier can be replaced at an appropriate time, and the purified gas It is possible to prevent the subsequent process using the material from being seriously affected and is economical.

  According to a sixth aspect of the flow path leak detection method, a second gas having a component different from the first gas flowing in the flow path is sprayed from the outside to the flow path, and the second gas is sprayed in the flow path. A gas flowing downstream from a location is introduced into a discharge chamber in which two electrodes to which a voltage is applied are arranged, a signal corresponding to the state of discharge between the two electrodes is obtained, and the flow path is based on the signal Is to detect leaks.

  According to the sixth aspect, since the second gas having a different component from the first gas flowing through the flow path is blown from the outside to the flow path, if there is a leak in the flow path, The second gas is mixed into the first gas, and the component of the gas flowing downstream with respect to the spray location changes, whereby the state of discharge between the two electrodes changes. Therefore, it is possible to obtain a signal corresponding to the state of discharge between the two electrodes and detect the leakage of the flow path based on the signal.

  By the way, in the conventional leak detection method, soap water is applied to the outside of the flow path and the flow path is detected by observing whether bubbles are generated or not. Was difficult.

  On the other hand, according to the sixth aspect, the change in the gas component can be detected with high sensitivity by detecting the change in the discharge between the two electrodes, so that the leak can be detected with high sensitivity. Even a minute leak can be easily detected.

  A leak detection method for a flow path according to a seventh aspect is the leak detection method according to the sixth aspect, wherein the second gas is kept at a positive pressure by a predetermined pressure rather than the pressure in the flow path.

  As in the seventh aspect, if the second gas blown to the flow path is set to a pressure considerably higher than the first gas in the flow path, a leak that does not occur in a normal state can be detected. Can be evaluated in advance.

  According to an eighth aspect of the present invention, there is provided a gas mixing method in which a plurality of gases are mixed by a plurality of flow rate control devices to obtain a mixed gas. Introducing a signal corresponding to the state of discharge between the two electrodes, and feeding back at least one of the plurality of flow rate control devices based on the signal so that the concentration of the mixed gas is constant It is something to control.

  In the conventional gas mixing method of obtaining a mixed gas by mixing a plurality of gases with a plurality of flow control devices, without detecting any concentration of the mixed gas, it is simply open loop without performing feedback control on the flow control device. I was doing control. However, even if the flow rate control device gives a flow rate command signal for commanding the desired flow rate to this, the flow rate of the gas does not immediately become the desired flow rate, but after the overshoot once exceeds the desired flow rate. It has the characteristic of being stabilized at a desired flow rate. For this reason, according to the conventional gas mixing method, the gas flow rate cannot be set to a desired flow rate from the beginning, and as a result, the concentration of the mixed gas cannot be set to the desired concentration from the beginning. Therefore, when the mixed gas is used, for example, in a semiconductor manufacturing process, there may be a problem.

  On the other hand, according to the eighth aspect, the concentration of the mixed gas is detected as the state of discharge between the two electrodes, and at least one of the plurality of flow rate control devices is feedback-controlled based on the detected state. Therefore, the concentration of the mixed gas can be set to a desired concentration from the beginning. In addition, since the gas concentration can be detected with a high sensitivity by changing the discharge between the electrodes, the concentration of the mixed gas can be accurately adjusted from the beginning to a desired concentration. Therefore, the mixed gas can be used, for example, in a semiconductor manufacturing process without causing any problems.

  A mixed gas supply method according to a ninth aspect is a mixed gas supply method in which a plurality of gases are mixed by a plurality of flow control devices and the mixed gas is supplied to a predetermined location, and two electrodes to which a voltage is applied are applied to the mixed gas. Is introduced into the discharge chamber, a signal corresponding to the state of discharge between the two electrodes is obtained, and the mixed gas is supplied to the predetermined location after the concentration of the mixed gas is stabilized based on the signal. Is.

  As described above, the flow rate control device has a characteristic that once it overshoots and becomes larger than the desired flow rate, and then stabilizes at the desired flow rate. According to the ninth aspect, the concentration of the mixed gas Is detected as a discharge state between the two electrodes, and based on this, the concentration of the mixed gas is stabilized and then supplied to the predetermined location. Therefore, the mixed gas having the desired concentration is accurately supplied to the predetermined location. can do. Therefore, the mixed gas can be used, for example, in a semiconductor manufacturing process without causing any problems.

  According to a tenth aspect of the method for putting in / out an article or the like, a gas exhausted from a room for taking in / out an article or a person is introduced into a discharge chamber in which two electrodes to which a voltage is applied are arranged, and a discharge between the two electrodes is performed. A signal corresponding to the state is obtained, and the article or person is taken in and out of the room after the signal falls within a predetermined range. Examples of the chamber include those related to semiconductor manufacturing, such as an air shower chamber where a person installed in front of a clean room enters and exits, a load lock chamber or a processing chamber (process chamber) for loading and unloading wafers as the article. Can be mentioned.

  Conventionally, when articles and the like are put in and out of these chambers, a predetermined time for staying in these chambers is determined in advance, and if the time has passed, it is considered that the articles and the like have been cleaned. However, the time required for cleaning naturally varies depending on the degree of dirt on the article. Therefore, if a sufficient cleanliness is to be ensured, the fixed time must be set longer, and the efficiency deteriorates. On the other hand, if the fixed time is set short for efficiency, a sufficient cleanliness is ensured. You may not be able to.

  On the other hand, according to the tenth aspect, the state of discharge between the two electrodes changes according to the impurity concentration of the gas exhausted from the chamber. (Purge state of dirt) is monitored as the state of discharge between the electrodes. And since articles etc. are taken in and out after the signal corresponding to the state of discharge between the electrodes falls within a predetermined range, the articles etc. when the articles reach a predetermined cleanliness regardless of the time the articles etc. stay in the room Will be put in and out. Therefore, according to the tenth aspect, articles and the like can be efficiently cleaned, and a sufficient cleanliness can always be ensured.

  A temperature-programmed desorption gas analysis method according to an eleventh aspect is the temperature-programmed desorption gas analysis method for analyzing a gas flowing through a heating chamber in which articles are arranged, wherein the gas flowing through the heating chamber has a voltage of It introduces into the discharge chamber which arrange | positions the two electrodes applied, obtains the signal according to the state of the discharge between the two electrodes, and analyzes the desorbed gas based on the signal.

  In a conventional temperature-programmed desorption gas analysis method, a gas flowing through a heating chamber in which articles are arranged is analyzed by a very expensive gas analyzer such as an atmospheric pressure mass spectrometer (APIMS).

  On the other hand, in the eleventh aspect, a signal corresponding to the state of discharge between the two electrodes is obtained by introducing into a discharge chamber in which two electrodes to which a voltage is applied are arranged, and based on the signal Since the desorption gas is analyzed, the device using this discharge can detect a change in gas with high sensitivity, but it is considerably cheaper than an ordinary gas analyzer. Cost can be reduced.

  The temperature-programmed desorption gas analysis method according to the twelfth aspect is the temperature-programmed desorption gas analysis method according to the eleventh aspect, wherein the gas flowing through the heating chamber is burned in the combustion chamber before being introduced into the discharge chamber. The gas after combustion is introduced into the discharge chamber.

According to the twelfth aspect, instead of directly measuring the desorbed gas, so measuring the desorbed gas after burning in the combustion chamber, O ₂ Ya as a gas to flow through the heating chamber (carrier gas) If air or the like is used, the organic substance of the desorption component is converted into CO ₂ gas and measured. If the desorbed gas containing the organic substance is introduced into the discharge chamber as it is, the organic substance easily contaminates the electrode, so the electrode must be frequently cleaned. In the twelfth aspect, the organic substance is converted into CO ₂ gas. Therefore, contamination of the electrode is reduced, and the frequency of electrode cleaning is reduced, which is preferable. Further, it is preferable to measure by converting an organic substance into CO ₂ because the concentration can be easily calculated.

  The methods according to the eleventh and twelfth aspects can be used, for example, to evaluate the cleanliness and dryness of articles such as wafers. In addition, when analyzing a measurement gas such as the atmosphere, by sucking the measurement gas through a filter or the like, the impurities or the like in the measurement gas are attached to the filter or the like, and the filter or the like is used as the article. The measurement gas can be analyzed by the methods according to the eleventh and twelfth aspects. In this case, the measurement gas can be analyzed even if the measurement gas exists at a location remote from the analysis location.

  ADVANTAGE OF THE INVENTION According to this invention, the detection method of the change of the atmosphere which can detect with high sensitivity that some kind of change among several types of changes has arisen in the atmosphere can be provided. In addition, various applied techniques using a measurement technique using the discharge phenomenon can be provided.

  Hereinafter, various embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic sectional view showing an example of a detection apparatus that can be used in the present invention. In FIG. 1, a plate-like electrode 1 has a flange portion 2 and an electrode portion 3 extending integrally with the flange portion 2, and a discharge electrode 4 is connected to the flange portion 2 via an insulating terminal 5. The electrode 1 and the discharge electrode 4 are attached so as to be exposed to the outside.

  The discharge electrode 4 is connected in parallel with a voltage measuring means (voltage monitor) 8 that measures the voltage value of the discharge via a variable resistor 7 provided in the housing 6, and the current that measures the current value of the discharge. A voltage value and a current value of the discharge applied between the electrode 4 and the electrode 1 by the power source 10 in series with the power source 10 via the measuring unit (current monitor) 9 are the voltage measuring unit 8 and the current measuring unit 9. And the value is outputted to a computer (not shown).

  If necessary, a mesh-like cover (not shown) such as a wire mesh surrounding the discharge electrode 4 and the electrode portion 3 from the safety aspect so as not to be touched directly by the hand to the discharge electrode 4 applied with voltage. May be attached to the flange portion 2.

  In the above configuration, when a voltage of, for example, about 1 KV to 3 KV is applied between the discharge electrode 4 and the electrode 1 by the power source 10 in the atmosphere in which a change is to be detected, the discharge electrode 4 and the electrode 1 Corona discharge occurred between them, the current value of the corona discharge was measured by the current measuring means 9, and the voltage value was measured by the voltage measuring means 10, and these measured values were processed by a computer and obtained. Changes in the atmosphere are detected by numerical values. This numerical value may be, for example, a value obtained by dividing the discharge voltage value by the discharge current value, or a value obtained by dividing the discharge voltage value by the integrated value of the discharge current value and the distance between the electrodes. When a constant current power source is used as the power source 10, the current measuring unit 9 can be removed, and a change in atmosphere can be detected based on the voltage value measured by the voltage measuring unit 10. Not only changes in the impurity concentration in the atmosphere, but also changes in pressure, temperature, changes in the amount of fine particles, changes in charged particles, changes in electromagnetic waves, etc. The voltage value changes and its sensitivity is very high.

  Therefore, if the detection apparatus shown in FIG. 1 is used, it is possible to detect that some change among a plurality of types of changes has occurred in the atmosphere. For this reason, this detection method is, for example, a method for detecting an abnormality in the gas flowing through the flow path, a method for detecting that a person has entered the room for crime prevention, or the like when the gas is burning. It can be used as a method for detecting the occurrence of incomplete combustion.

  FIG. 2 is a schematic cross-sectional view showing another example of a detection apparatus that can be used in the present invention. In FIG. 2, a metal block 21 made of stainless steel or the like has a substantially H-shaped discharge chamber 22 that passes through the center thereof. The discharge chamber 22 has a gas inflow chamber 24 connected to the measurement gas inflow port 23 on one side thereof, and a gas outflow chamber 26 connected to the gas outflow port 25 on the other side. 26 communicates with a narrow cylindrical passage 27, and an inner peripheral wall surface 41 of the passage 27 is a cylindrical electrode. A flange 29 having a gas inflow port 23 is hermetically fixed to the gas inflow chamber portion 24 side through a metal packing 28, and a gas outflow port is also provided to the gas outflow chamber portion 26 side through a metal packing 30. A flange 31 having 25 is fixed hermetically. The block 21 and the flanges 29 and 31 are grounded, thereby forming a discharge chamber 22. One wire electrode as the discharge electrode 32 is provided in the center of the passage in the discharge chamber 22. One end of the electrode 32 is welded to a terminal 34 attached to the block 21 via an insulating terminal 33, and the other end is welded to a terminal 36 similarly attached to the block 21 via an insulating terminal 35. It is stretched horizontally. Further, the gas inlet 23 and the gas outlet 24 are provided with meshes 42 and 43 such as a flame prevention wire net for preventing the flame from coming out when a flame is generated in the discharge chamber 22. Yes. The above elements 21 to 36 and 41 to 43 constitute the discharge part 37 of the detection device.

  A terminal 34 to which a discharge electrode (wire electrode) 32 is welded is connected in series with a power source 39 via a current measuring means (current monitor) 38 for measuring a discharge current value, and measures a discharge voltage value. A voltage measuring means (voltage monitor) 40 is connected in parallel. Then, the voltage value and current value of the discharge applied between the discharge electrode 32 and the electrode 41 by the power source 39 are measured by the voltage measuring means 40 and the current measuring means 38, and the values are stored in a computer (not shown). It is output. The above elements 38 to 40 constitute the power supply unit 45 of the detection device.

  In the above configuration, when gas (atmosphere) is introduced into the discharge chamber 22 from the gas inlet 23 and a voltage of, for example, about 1 KV to 3 KV is applied between the electrodes 32 and 41 by the power source 39, the electrode 32 is provided. , 41, a current value of the corona discharge is measured by the current measuring means 38, a voltage value is measured by the voltage measuring means 40, and these measured values are processed by a computer and obtained. The change in the atmosphere is detected by the obtained numerical value. This numerical value may be, for example, a value obtained by dividing the discharge voltage value by the discharge current value, or a value obtained by dividing the discharge voltage value by the integrated value of the discharge current value and the distance between the electrodes. Further, when a constant current power source is used as the power source 40, the current measuring unit 38 can be removed, and a change in atmosphere can be detected based on the voltage value measured by the voltage measuring unit 40. Numerical values obtained by computer processing and voltage values when using a constant current power source not only due to changes in the concentration of the gas introduced into the discharge chamber 22 and the impurity concentration in the gas but also due to changes in pressure, temperature, etc. Changes and its sensitivity is very high. In addition, by adjusting the pressure and temperature of the introduced gas to predetermined values, the concentration and impurity concentration of the gas can be measured from numerical values obtained by computer processing and voltage values when using a constant current power supply. can do.

  Therefore, if the detection apparatus shown in FIG. 2 is used, it is possible to detect that some of a plurality of types of changes have occurred in the introduced gas, and to measure the concentration and impurities of the introduced gas. be able to.

  The two electrodes 3 and 4 exposed to the outside as shown in FIG. 1 and the two electrodes 27 and 41 provided in the discharge chamber as shown in FIG. 2 are not limited to the illustrated form. For example, instead of the electrodes 27 and 41, a needle-like electrode and a counter electrode facing the electrode can be used.

FIG. 3 shows a gas analyzer according to an embodiment of the present invention. This gas analyzer performs a plurality of types of analysis on the N ₂ gas, Ar gas, and H ₂ gas flowing through the flow paths 51-53, respectively. This gas analyzer includes a plurality of gas analyzers A, B,... That perform different types of analysis. Examples of these gas analyzers include a particle counter, an oxygen meter, a dew point meter, a gas chromatograph, a mass spectrometer, and an atmospheric pressure mass spectrometer (APIMS). Corresponding to the respective gases flowing through the flow paths 51 to 53, gas change detecting devices 54 to 56 for detecting changes of the respective gases are provided. In the present embodiment, the detection devices shown in FIG. 2 are used as the gas change detection devices 54 to 56, respectively. The flow paths 51 to 53 are respectively connected to gas inlets (corresponding to 23 in FIG. 2) of the detection devices 54 to 56, and electromagnetically connected to the flow paths 60 connected to the gas analyzers A, B. The valves 57 to 59 are connected to each other. Gas outlets (corresponding to 25 in FIG. 2) of the detection devices 54 to 56 are open to the atmosphere. Signals from the detection devices 54 to 56 are input to the valve control unit 61. The valve control unit 61 controls the valves 57 to 59, and when a signal indicating that a change has occurred in the gas is obtained from any of the detection devices 54 to 56, the corresponding one of the valves 57 to 59 is used. Open the valve to close and close the other valves.

  According to this gas analyzer, the gas in each flow channel 51-53 is monitored by each detection device 54-56 to detect a change in the gas, and the gas flow channel in which the change is detected is controlled by the control unit 61N. Then, the gas that is selectively connected to the flow path 60 by the valves 57 to 59 and the change is detected is selectively analyzed by the gas analyzers A, B. Although the gas in each of the flow paths 51 to 53 is not analyzed by the gas analyzer at the same time, the gas whose change has been detected (that is, the gas in which an abnormality or the like has occurred) is analyzed by the gas analyzer. Does not occur. In this gas analyzer, a set of gas analyzers A, B... May be provided for the plurality of flow paths 51 to 53, and the detection devices 54 to 56 are considerably more than the gas analyzer. Since the gas analyzer is inexpensive, the overall cost can be greatly reduced.

  If no signal indicating that the gas has changed is obtained from any of the detection devices 54 to 56, all the valves 57 to 59 are closed (may be opened) by the control unit 61, and the gas analysis is performed. It is not necessary to operate the meters A, B... Or the valves 57 to 59 are controlled by the controller 61 so that the gas analyzers A, B,. .. May be connected to the gas analyzers A, B,.

  By the way, when using the detection apparatus shown in FIG. 1 or FIG. 2, the voltage applied between the electrodes 3 and 4 or between the electrodes 32 and 41 is not continuous but intermittent as shown in FIG. It is preferable to apply the voltage only when it is necessary for detection or measurement (for example, only for 10 seconds per hour). This is because the life of the electrode can be extended by delaying the progress of the deterioration of the electrode. In FIG. 4, the horizontal axis indicates the elapsed time, and the vertical axis indicates the state of voltage application between the two electrodes.

  FIG. 5 shows an example of a method of using the detection apparatus shown in FIG. This usage method is a usage method in the case of detecting the change and the characteristic value (concentration, impurity concentration, etc.) of the gas flowing through the plurality of flow paths 71 to 73 as necessary. In this method of use, discharge sections 74 to 76 corresponding to the discharge section 37 in FIG. 2 are always provided in the flow paths 71 to 73, respectively, and one power supply section 77 corresponding to the power supply section 45 in FIG. Just prepare. And when detecting about the gas of each flow path 71-73, the one power supply part 77 is connected with respect to the discharge parts 74-76. In this way, since only one power supply unit 77 is required, the cost can be greatly reduced. Moreover, since the discharge parts 74-76 are always provided in the flow paths 71-73, the gas always flows through the discharge chamber. The value detection can be started. Normally, if no discharge part is provided in the flow paths 71 to 73 and the discharge part is connected to the flow paths 71 to 73 only at the time of detection, only one discharge part is required. Until it is purged, accurate detection cannot be performed, and rapid detection cannot be performed.

  FIG. 6 shows a method for monitoring the life of a gas purifier according to an embodiment of the present invention. In this method, a detection device 82 corresponding to the detection device shown in FIG. 2 is provided downstream of the gas purification device 80 in the flow path 81 provided with the gas purification device 80. As a result, the gas completely flowing through the gas purifier 80 is introduced into the discharge chamber of the detection device 82. When the gas purifier 80 approaches or reaches the end of its life, the degree of gas purification decreases, so the state of discharge between the two electrodes of the detection device 82 changes. Therefore, the life of the gas purifier 80 can be monitored based on a signal corresponding to the state of discharge between the two electrodes obtained from the detection device 82. In FIG. 6, 80 a is a gas inlet of the gas purifier 80, 80 b is a gas outlet, and 90 is a broken region such as an element of the gas purifier 80.

  FIG. 7 shows a gas purifier lifetime monitoring method according to another embodiment of the present invention. In FIG. 7, the same or corresponding elements as those in FIG. 6 are denoted by the same reference numerals. In this method, the gas inlet of the detection device 82 is connected in the middle of the gas purifier 80, and the gas that has flowed through the gas purifier 80 is introduced into the discharge chamber of the gas purifier 80. The gas outlet of the detection device 82 is open to the atmosphere. The elements and the like of the gas purifier 80 have their lifetimes exhausted when the rupture region 90 gradually expands from the gas inlet side 80a toward the gas outlet side 80b. Therefore, according to the method shown in FIG. 7, it can be known that the lifetime is nearer than that in the method shown in FIG. 6, and the lifetime of the gas purifier 80 is surely known before the lifetime is exhausted. be able to.

  The gas purifier 80 may be of any type, such as one using an adsorbent, a getter type, or a catalyst type.

  FIG. 8 is a longitudinal sectional view showing an example of the joint portion 100 in the gas flow path. In FIG. 8, 101 is a joint body, 102 is a gasket, 103 is a sleeve, 104 is a tube welded to the sleeve 102, and 105 is a union nut. By screwing the union nut 105 into the joint main body 101, the sleeve 103 is pressed against the joint main body 101 via the gasket 102, whereby the airtightness of the flow path 100 is maintained. Since leaks are likely to occur in the vicinity of the gasket 102, the union nut 105 has holes 105a and 105b for detecting leaks on the upper and lower surfaces thereof.

FIG. 9 shows a flow path leak detection method according to an embodiment of the present invention. In FIG. 9, the first gas flow path 110 has the joint portion 100 shown in FIG. In this method, the tip of a nozzle 112 connected to a cylinder 111 that stores a second gas having a different component from the first gas flowing through the flow path 100 is inserted into the hole 105 a of the union nut 105 of the joint portion 100. Then, a valve (not shown) is opened and the second gas is blown from the hole 105a. Note that the size of the tip of the nozzle 112 is preferably substantially the same as that of the hole 105a. And the gas which flows downstream with respect to the joint part 100 in the flow path 110 is introduce | transduced into the discharge chamber of the detection apparatus 113 corresponded to the detection apparatus shown in FIG. The gas outlet of the detection device 113 is open to the atmosphere. Although not shown in the drawing, the cylinder 113 is provided with a pressure regulator so that the pressure of the second gas can be adjusted to a desired pressure. Since the second gas having a different component from the first gas flowing through the flow path 110 is blown from the outside to the joint portion 100 of the flow path 110, if there is a leak in the joint portion 100 of the flow path 110, the flow path 110 The second gas is mixed into the first gas, and the component of the gas flowing downstream with respect to the joint portion 100 changes, whereby the state of discharge between the two electrodes of the detection device 113 changes.
Therefore, the leak of the joint portion 100 of the flow path 110 can be detected based on the signal corresponding to the state of discharge between the two electrodes obtained from the detection device 113.

  FIG. 10 shows a flow path leak detection method according to another embodiment of the present invention. 10, elements that are the same as or correspond to those in FIG. 9 are given the same reference numerals, and redundant descriptions thereof are omitted. The method shown in FIG. 10 differs from the method shown in FIG. 9 in that the tip of the nozzle 112 is directly inserted into the hole 105a of the joint part 100 in FIG. 9, whereas the joint part 100 is covered in FIG. The only point is that the nozzle 112 is covered with the nozzle 114 and the tip of the nozzle 112 is inserted into the cover 114. Therefore, in this method, the second gas from the nozzle 112 is kept at a positive pressure within the cover 114 by a predetermined pressure rather than the pressure in the flow path 110. If the second gas blown to the flow path 110 is set to a pressure much higher than the first gas in the flow path 110, a leak that does not occur in a normal state can be detected, and the resistance of the flow path 110 to the leak is preliminarily determined. Can be evaluated.

  In FIG. 10, a jig 120 and a cylinder 111 as shown in FIG. 11 can be used instead of the nozzle 112, the cylinder 111 and the cover 114. The jig includes a pair of clamping portions 122 and 123 that clamp the upper and lower surfaces of the union nut 105 of the joint portion 100, and a pair of handles 124 and 125. The sandwiching portion 122 and the handle 124 are integrated, the sandwiching portion 123 and the handle 125 are integrated, and these are pivotally connected by a fulcrum portion 126. The fulcrum 126 is urged by a spring not shown in the drawing in a direction in which the distance between the clamping parts 122 and 123 is reduced. In one clamping part 122, a recess 122a is formed, and an air supply path 123b is formed from the outside to the recess 122a. Packings 127 and 128 are provided on the contact surfaces of the clamping portions 122 and 123 with the union nut 105, respectively. The cylinder 121 and the air supply passage 122b are connected by a flexible pipe 129. The cylinder 121 is provided with a valve and a pressure regulator not shown in the drawings, as in the case of FIGS. 9 and 10. According to this jig 120, holding the handles 124, 125 in the hand, narrowing the interval to widen the interval between the holding parts 122, 123, and releasing the hand from the handles 124, 125, the holding parts 122, 123 are unioned. The nut 105 can be clamped. At this time, the hole 105a of the union nut 105 of the joint part 100 opens into the recess 122a, and the hole 105b is closed by the packing 128. As a result, the situation is substantially the same as in FIG.

  FIG. 12 shows a gas mixing method according to an embodiment of the present invention. In this method, the gas a and the gas b are mixed by the flow rate control devices 131 and 132, and the mixed gas is supplied to a predetermined location by the flow path 133. A part of this mixed gas is introduced into the discharge chamber of the detection device 134 corresponding to the detection device shown in FIG. The gas outlet of the detection device 134 is open to the atmosphere. When the concentration of the mixed gas changes, the state of discharge between the two electrodes of the detection device 134 changes, so that the detection signal obtained from the detection device 134 (the signal indicating the state of discharge between the two electrodes) is mixed. It will indicate the concentration of the gas. The control unit 135 feedback-controls the flow rate control devices 131 and 132 based on this signal so that the concentration of the mixed gas becomes a predetermined value. If the control unit 135 performs open loop control without performing such feedback control, the detection signal from the detection device 134, that is, the concentration of the mixed gas, is as shown in FIG. Although the overshoot 136 is generated, according to the mixing method shown in FIG. 12, the desired concentration can be accurately obtained from the beginning as shown in FIG. 13B by the feedback control described above.

  FIG. 14 shows a gas mixing method according to another embodiment of the present invention. In FIG. 14, elements that are the same as or correspond to those in FIG. In this mixing method, the mixed gas flow path 133 obtained by the flow rate control devices 131 and 132 is connected to the flow path 141 for supplying the mixed gas to a predetermined location via the electromagnetic valve 142 and the electromagnetic valve 143. It is open to the atmosphere through. In this method, since the flow rate control devices 131 and 132 are not feedback-controlled, the detection signal from the detection device 134, that is, the concentration of the mixed gas, has an overshoot 136 at the beginning of mixing as shown in FIG. Arise. As shown in FIG. 15B, the control unit 140 opens the valve 141 after the detection signal from the detection device 134, that is, the concentration of the mixed gas is stabilized, and flows the mixed gas through the flow path 141 to a predetermined position. Supply. Further, the control unit 140 controls the valve 143 so that the opening / closing thereof is opposite to the opening / closing of the valve 142. In this method, although the overshoot 136 occurs in the concentration of the mixed gas obtained in the flow path 133 in this way, the mixed gas is discarded via the valve 143 and supplied to a predetermined location until the concentration is stabilized. Therefore, after this concentration is stabilized, it is supplied to a predetermined location via the valve 142. Therefore, the concentration of the mixed gas supplied to the predetermined location is accurately set to a desired concentration as shown in FIG. It becomes.

  FIG. 16 shows a method for putting in and out an article according to an embodiment of the present invention. In FIG. 16, 150 is a wafer, 151 is a load lock chamber, 152 is a processing chamber (process chamber) for performing a semiconductor manufacturing process, 153 is an air supply path for supplying purge gas to the load lock chamber 151, and 154 is from the load lock chamber 151. An exhaust path for exhausting gas, 155 is an air supply path for supplying purge gas to the processing chamber 152, and 156 is an exhaust path for exhausting gas from the processing chamber 152. In this method, part of the gas exhausted from the load lock chamber 151 and the processing chamber 156 is introduced into the discharge chambers of the detection devices 157 and 158 corresponding to the detection device shown in FIG. Since the state of discharge between the two electrodes of the detectors 157 and 158 changes according to the impurity concentration of the gas exhausted from the chambers 151 and 152, the cleanliness of the chambers 151 and 152 (that is, the wafer 150) (Purged state of dirt) is monitored as the state of discharge between the electrodes of the detection devices 157 and 158. In this method, a signal corresponding to the state of discharge between the electrodes from each of the detection devices 157 and 158 is given to a transfer device (not shown) that transfers the wafer 150, and the signal falls within a predetermined range. After that (that is, when the predetermined cleanliness is reached), the wafer 150 is put in and out of the chambers 151 and 152 by the transfer device. Therefore, regardless of the time during which the wafer 150 stays in the chambers 151 and 152, articles and the like are taken in and out when the predetermined cleanliness is reached. For this reason, it is possible to efficiently clean the wafer 150 and always ensure a sufficient cleanliness.

  FIG. 17 shows a method for putting in and out a person according to an embodiment of the present invention. In FIG. 17, 160 is a person, 161 is an air shower room, 162 is a clean room for semiconductor manufacturing, 163 is an air supply passage for air shower, 164 is an exhaust for exhausting air from the air shower room 161 Road. In this method, a part of the air exhausted from the air shower chamber 161 is introduced into the discharge chamber of the detection device 165 corresponding to the detection device shown in FIG. Since the state of discharge between the two electrodes of the detection device 165 changes according to the impurity concentration of the exhausted air, the cleanliness of the air shower chamber 165 (that is, the purging state of dirt of the person 160) is determined by the detection device. The state of discharge between the 165 electrodes is monitored. In this method, a signal corresponding to the state of discharge between the electrodes from the detection device 165 is given to a door device (not shown) and a display device (not shown) of the air shower chamber 161, and the signal is predetermined. The door device and the display device control the opening / closing and locking state of the door so that the person 160 enters and exits the air shower chambers 161 and 162 after reaching the range (that is, the predetermined cleanliness is reached). Indication of whether entry / exit is possible or not. Therefore, regardless of the time during which the person 160 stays in the chamber 160, the person 160 enters and exits when the predetermined cleanliness is reached. Therefore, it is possible to efficiently clean the person 160 and always ensure a sufficient cleanliness.

  FIG. 18 is a diagram showing a temperature-programmed desorption gas analysis method according to an embodiment of the present invention. In FIG. 18, the gas from the cylinder 170 passes through a heating chamber 174 in which an article 173 such as a wafer is disposed after the pressure and the flow rate control device 172 set the pressure and flow rate to predetermined values. Further, it is introduced into a discharge chamber of a detection device 175 corresponding to the detection device shown in FIG. The gas outlet of the detection device 175 is open to the atmosphere. In FIG. 18, reference numeral 176 denotes an infrared lamp or the like as a heating source for heating the heating chamber 174. The gas that has passed through the heating chamber 174 includes a component that has been desorbed from the article 173. Since the state of discharge between the two electrodes of the detection device 175 changes depending on the component, the desorption component can be analyzed based on a signal corresponding to the discharge state obtained from the detection device 175.

FIG. 19 is a diagram illustrating a temperature programmed desorption gas analysis method according to another embodiment of the present invention. In FIG. 19, the same or corresponding elements as those in FIG. 18 are denoted by the same reference numerals. The method of FIG. 19 differs from the method of FIG. 18 only in that a combustion chamber 180 is provided between the heating chamber 174 and the detection device 175. In this method, the desorbed gas that has passed through the heating chamber 174 is not measured as it is, but is measured after the desorbed gas is burned in the combustion chamber 180. For this reason, when O ₂ , air, or the like is used as a gas (carrier gas) to flow through the heating chamber 174, the organic substance of the desorption component is converted into CO ₂ gas and measured. If the desorbed gas containing the organic substance is directly introduced into the discharge chamber of the detection device 175, the organic substance easily contaminates the electrode. Therefore, the electrode must be frequently cleaned. According to the method of FIG. Since it is converted into _two gases, contamination of the electrode is reduced, and the frequency of electrode cleaning is reduced, which is preferable. Further, it is preferable to measure by converting an organic substance into CO ₂ because the concentration can be easily calculated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

It is a schematic sectional drawing which shows an example of the detection apparatus which can be used in this invention. It is a schematic sectional drawing which shows the other example of the detection apparatus which can be used in this invention. It is a schematic block diagram which shows the gas analyzer by one embodiment of this invention. It is a figure which shows an example of the mode of the voltage application to a discharge electrode. It is a figure which shows an example of the usage method of the detection apparatus shown in FIG. It is a figure which shows the lifetime monitoring method of the gas purifier by one embodiment of this invention. It is a figure which shows the lifetime monitoring method of the gas purifier by other embodiment of this invention. It is a longitudinal cross-sectional view which shows an example of the joint part in the flow path of gas. It is a figure which shows the leak detection method of the flow path by one embodiment of this invention. 6 shows a flow path leak detection method according to another embodiment of the present invention. It is a partially cutaway view showing a jig that can be used in a leak detection method for a flow path. It is a figure which shows the gas mixing method by one embodiment of this invention. It is a figure for demonstrating operation | movement of the gas mixing method shown in FIG. It is a figure which shows the gas mixing method by other embodiment of this invention. It is a figure for demonstrating operation | movement of the gas mixing method shown in FIG. It is a figure which shows the taking in / out method of the articles | goods by one embodiment of this invention. It is a figure which shows the human withdrawal method by one embodiment of this invention. It is a figure which shows the temperature rising desorption gas analysis method by one embodiment of this invention. It is a figure which shows the temperature-programmed desorption gas analysis method by other embodiment of this invention.

Explanation of symbols

3, 4, 32, 41 Electrode 22 Discharge chamber 10, 39 Power supply 8, 40 Voltage measuring means 9, 38 Current measuring means 54, 55, 56, 82, 113, 134 Detector 57, 58, 59, 142, 143 Valve 61 Valve control unit 80 Gas purifier 131, 132 Flow rate control device 135, 140 Control unit 150, 173 Wafer 151 Load lock chamber 152 Processing chamber 157, 158, 165, 175 Detection device 161 Air shower chamber 162 Clean room 174 Heating chamber 180 Combustion Room

Claims (2)

In a temperature-programmed desorption gas analysis method for analyzing a gas flowing through a heating chamber in which articles are arranged, the gas flowing through the heating chamber is introduced into a discharge chamber in which two electrodes to which a voltage is applied are arranged. A temperature-programmed desorption gas analysis method characterized in that a signal corresponding to the state of discharge between the two electrodes is obtained, and desorption gas analysis is performed based on the signal. 2. The temperature-programmed desorption gas analysis according to claim 1, wherein the gas flowing through the heating chamber is combusted in the combustion chamber before being introduced into the discharge chamber, and the gas after combustion is introduced into the discharge chamber. Method.

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