JPH06138113A - Gas chromatograph analyzer - Google Patents

Abstract

PURPOSE:To provide a gas chromatograph analyzer, which can prevent the leakage of gas and the mixing of oxygen and/or moisture. CONSTITUTION:In a gas chromatograph analyzer 20 including a system, wherein sample gas G to be analyzed passes, and a system wherein carrier gas passes, two system are surrounded by a tightly sealing case 26, and purging mechanisms 28 and 30, which replace the atmosphere in the case with a purging gas, are provided. A branching mechanism 22 branches a branching system from the carrier-gas passing system. A connecting mechanism 24 connects the branching system to the system through which sample-gas G passes. these mechanisms are also provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to gas detection and, more particularly, to improvements in gas chromatograph analysis equipment.

[0002]

2. Description of the Related Art For example, in a semiconductor manufacturing process, toxic gases such as arsine, phosphine and silane are used as a material gas. In many cases, these gases are used after being diluted with nitrogen, argon, hydrogen, etc., which are called balance gases, to a predetermined concentration, or mixed with several kinds of material gases. Therefore, it is important to control and check the mixing ratio of the material gas and the balance. Further, since a material gas such as silane gas has a high reactivity with oxygen, moisture, etc., it is important to prevent contamination of contaminants such as air. Therefore, in-line gas analysis is required.

However, a detector for analyzing such a material gas is often of a type using a potentiostatic electrolysis type sensor. Therefore, it may react with a gas other than the detection target, and a gas having a concentration of 100 ppm or more cannot be measured.

On the other hand, an apparatus has been proposed which focuses on the basic principle of gas chromatography, which allows separation of a plurality of compounds and analysis of high-concentration gas, and FIGS. 1 shows a conventional gas chromatograph device. The sample gas to be analyzed (indicated by the arrow G in FIGS. 3 and 4) is the feed line (inlet line) IL.
It is further introduced and supplied to the sample electrode column 4 via the solenoid valve 1, the sample gas injection device 2, and the inlet side joint 3. Then, the sample gas is separated in the column 4 and sent to the detector 6 via the outlet joint 5. The detector 6 causes an electrical change corresponding to the contained gas, and the electrical change is recorded by the recorder 8 to measure the gas concentration. Then, the gas is discharged to the outside of the gas chromatograph from the discharge line OL. The above series of processing is performed in the system through which the sample gas passes.

The system through which the carrier gas passes is as follows. That is, the carrier gas is sent from the carrier gas cylinder 9 to the three-way joint 12 through the pressure reducing valve 10 and the desiccant container 11 filled with the desiccant. Here, although not shown, the three-way joint 1
There are many joints in the piping system up to 2.
Is provided.

The carrier gas passing through the sample electrode column 4 and the like passes through the three-way joint 12 and is sent toward the inlet side joint 3, and passes through the column 4, the outlet side joint 5 and the detector 6 from the exhaust line OL to the gas chromatograph. It is discharged outside the tograph device. On the other hand, the carrier gas passing through the control electrode column 15 and the like is discharged from the three-way joint 12 through the inlet side joint 14, the control electrode column 15, the output side joint 16, and the detector 6 from the control electrode column discharge line ROL. It 3 and 4, the three-way joint 12
The line including the sample electrode column 4 (sample electrode side line) on the downstream side of the reference numeral GL is indicated by the reference symbol GL, and the line including the control electrode side column 15 (reference electrode side line) is indicated by the reference symbol RL. In addition,
In FIG. 3, reference numeral 18 indicates a constant temperature bath, and reference numeral 19 indicates a power source.

[0007]

The most important thing to note in the analysis of this type of material gas is its low toxicity and reactivity (some of which burn out only when it comes into contact with air). Even if the material gas is at a concentration, it should never be released unless detoxification measures are taken.When introducing the material gas into the pipe or removing the pipe, completely evacuate the inside of the pipe or use an inert gas. , And never contact the material gas with air, and do not allow the gas whose composition has changed or the polluted gas to flow back to the supply source such as the production line by the analysis. If a high-concentration material gas is sucked, the vacuum pump will be contaminated and pose a danger when opened.For residual gas, pressurization by injecting an inert gas and discharging to the exclusion measure side will be repeated. Degree that must be sucked into after sufficiently lowered, must adhere to.

However, when the gas chromatograph apparatus described with reference to FIGS. 3 and 4 is used, the joint portion used for the pipe and column (separation pipe) through which the carrier gas passes, and the sample gas injection. There is a possibility that sample gas, that is, toxic gas, may leak into the atmosphere from the inlet or the like.

Further, a joint portion used for a pipe and a column (separation pipe) through which the carrier gas passes,
There is also a problem that oxygen and water in the atmosphere are mixed (in a trace amount) into the carrier gas through the sample gas inlet or the like. That is, a compound such as monosilane contained in the sample gas, which has high reactivity with oxygen and water, reacts with oxygen and water mixed in the pipe. As a result, for example, in the case of monosilane, a compound such as SiO2 is produced, the produced compound is accumulated in a part of the pipe, and eventually the pipe is blocked. Further, a reaction occurs in the pipe, which causes a problem that quantitative analysis becomes impossible.

The present invention has been proposed in view of the above-mentioned problems of the prior art, and it is possible to prevent leakage of the sample gas from the joint portion and the injection port, and the mixture of oxygen and / or water into the gas chromatograph. The purpose is to provide a topograph analyzer.

[0011]

A gas chromatograph analysis apparatus of the present invention is a gas chromatograph analysis apparatus including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, wherein the two systems are closed cases. And a purge mechanism for replacing the atmosphere in the case with a purge gas.

Here, an inert gas, a carrier gas or the like can be used as the purge gas. Then, it is preferable to use an inert gas such as helium or argon as the carrier gas.

Further, the gas chromatograph analysis apparatus of the present invention is a gas chromatograph analysis apparatus including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, and a branch system from a system through which the carrier gas passes. It includes a branching mechanism for branching and a connecting mechanism for connecting the branching system to a system through which the sample gas passes.

Further, the gas chromatograph analysis apparatus of the present invention is a gas chromatograph analysis apparatus including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, wherein the two systems are enclosed by a closed case, A purge mechanism for replacing the atmosphere in the case with a purge gas, a branch mechanism for branching a branch system from a system through which the carrier gas passes, and a connection mechanism for connecting the branch system to a system through which the sample gas passes. There is.

[0015]

According to the gas chromatograph analysis apparatus of the present invention having the above-mentioned structure, the system through which the sample gas to be analyzed and the system through which the carrier gas passes are surrounded by a sealed case, and the atmosphere in the case is surrounded. Since it is configured to be replaced by a purging mechanism, the sample gas, that is, the toxic gas is temporarily discharged from the joint part used in the pipe and column (separation pipe) through which the carrier gas passes and the sample gas inlet. Even if it leaks, it is surrounded by a closed case, so there is no danger of it being diffused into the atmosphere. Then, a purge gas such as an inert gas is supplied into the case, and functions to purge unnecessary oxygen and moisture. Further, even if the inert gas is mixed into the system through the joint portion or the sample gas inlet, it does not react with the sample gas or the like, so that there is no fear that the reaction product will block the pipe.

Further, in the gas chromatograph analyzer of the present invention, the branching mechanism and the connecting mechanism allow the carrier gas to be introduced from the carrier gas supply source to the portion for analyzing the sample gas almost without passing through the joint portion or the like. Also, the carrier gas introduced into the system through which the sample gas passes can be analyzed. That is, since the carrier gas flowing in the system through which the sample gas passes and the carrier gas flowing in the system through which the carrier gas passes from the carrier gas supply source are simultaneously introduced into the analysis mechanism,
From the analysis result, it is determined whether or not some impurities such as oxygen and water are mixed in from the joint portion or the like in the system through which the carrier gas passes.

Since the carrier gas can be made to flow in the system through which the sample gas passes by the branching mechanism and the connecting mechanism, the sample gas remaining in the system through which the sample gas passes can be purged with the carrier gas. Of. Further, since the carrier gas flowing in the system through which the sample gas passes and the carrier gas flowing in the system through which the carrier gas passes from the carrier gas supply source are simultaneously introduced into the analysis mechanism, the sample gas passes from the analysis result. It is determined whether the purge in the system is sufficient or whether impurities such as oxygen and water from the joint portion in the system through which the sample gas passes are mixed.

As described above, according to the present invention, the sample gas leaks to the outside of the gas chromatograph analyzer to contaminate the external environment, or reacts with oxygen or water entering the device to cause the clogging of the pipe. The risk of producing a compound that is In addition, even if oxygen or water enters or mixes with the carrier gas or sample gas supply system, or if the sample gas that could not be purged remains in the sample gas supply system, etc. I can judge. Further, even if the sample gas remains in the system, it is possible to easily purge the residual sample gas by flowing the carrier gas in the system.

In the purging mechanism described above, the purge gas that replaces the inside of the case and is discharged to the outside of the case does not pollute the environment even if it contains a toxic gas that is a sample. Since it is diluted to the level, there is no problem if it is discharged out of the system as it is. However, as a more preferable embodiment, a mechanism for treating toxic components contained in the purged gas may be provided in the discharge system of the purge mechanism.

[0020]

Embodiments of the present invention will now be described with reference to FIGS.

1 and 2 show an embodiment of the present invention. However, the same members as those in FIGS. 3 and 4 are denoted by the same reference numerals. The gas chromatograph analyzer 20 shown in FIGS. 1 and 2 has a three-way joint 22 interposed between the pressure reducing valve 10 and the desiccant container 11, and the pipe from the carrier gas cylinder 9 is connected to the sample gas supply line from the three-way joint 22. It branches to the three-way cock 24 interposed in the IL.

Further, most of the piping system (particularly including the part extending from the desiccant container 11 where many joints or joints are arranged to the three-way joint 12) is provided by the purge case indicated by reference numeral 26 (dotted line) in FIG. Be surrounded. An inert gas (purge gas) is introduced into the purge case 26 from the purge gas supply port 28. On the other hand, the inert gas already present in the purge case 26 is sent to the outside from the exhaust port 30 and the purge gas is replaced. Although not clearly shown in FIG. 1, a toxic gas treatment mechanism may be provided on the downstream side of the discharge port 30 to prevent environmental pollution even if leakage of toxic components occurs. Here, in FIG. 1, the inside of the case is constantly replaced with the inert gas, but the supply and discharge of the inert gas are performed only for a certain period of time, and the purge case 26 is normally filled with the inert gas only in a normal time. May be.

Although not clearly shown in the drawing, the pipe portion from the desiccant container 11 to the three-way joint 12 is provided with equipment such as a pressure gauge and a flow meter for adjusting the flow rate. And many joint parts are provided in order to connect these devices and piping.

In FIG. 1, reference numeral 32 indicates a solenoid valve interposed in the discharge line OL-2.

Next, the operation of the embodiment shown in FIGS. 1 and 2 will be described.

The mode of analyzing the sample gas is the same as that described above with reference to FIGS. In this case, three-way cock 2
4 allows the sample gas G to pass to the sample gas injection device 2 side. Here, since various devices including the piping system through which the sample gas G flows are completely surrounded by the purge case 26,
Even if the sample gas G leaks from a part of the piping system, there is no possibility of leaking to the outside of the analyzer 20. Further, since the purge case 26 is filled with a purge gas such as an inert gas, even if the purge gas enters the piping system,
It does not cause a chemical reaction with the sample gas G or the like to generate a compound such as SiO2, and does not block the pipe.

Further, according to the embodiment shown in FIGS. 1 and 2, it is possible to detect the invasion of oxygen or water from the outside into the piping system. In such a detection, the carrier gas immediately after leaving the pressure reducing valve 10 is connected to the three-way joint 2
It is branched at 2, introduced into the sample electrode side line GL via the three-way cock 24 and the sample gas injection device 2, separated by the sample electrode column 4, and analyzed by the detector 6. Then, the analysis result is input to the recorder 8.

Here, if impurities such as oxygen and water are not mixed in the piping system from the carrier gas supply cylinder 9 to the inlet joint 3, the analysis result of the carrier gas introduced into the symmetric pole column 15 (recorder 8 No waveform appears on the chromatogram of (already entered in). However, if oxygen and water are mixed in the piping system, a waveform should appear on the chromatogram. Therefore, a determination mechanism (not shown) can determine whether oxygen, water, or other impurities are mixed in the pipe from the carrier gas supply cylinder 9 to the inlet joint 3 based on the above analysis result. Further, since the carrier gas flowing in the system through which the sample gas passes and the carrier gas flowing in the system through which the carrier gas passes from the carrier gas supply source are simultaneously introduced into the analysis mechanism, the sample gas passes from the analysis result. It is determined whether the purge in the system is sufficient or whether impurities such as oxygen and water from the joint portion in the system through which the sample gas passes are mixed.

Next, with reference to FIGS. 5 and 6, a diluter suitably combined with the embodiment of FIG. 1 will be described.

In the embodiment described with reference to FIG. 1, the gas for semiconductor production may be sent to the supply line IL as it is, but in many cases, the gas chromatograph analyzer 20 is diluted with a predetermined ratio. Is supplied to. FIG. 5 shows such a mode in which the sample gas G is supplied to the analyzer 20 in a diluted state. In FIG. 5, a source gas generation source that generates a large amount of a gas to be analyzed, such as a semiconductor manufacturing facility, is indicated by symbol S. Then, the gas OG generated from the source gas generation source S is sent to the diluter 40 via the main valve 38 and the line 39. Here, the gas OG that has not been sent to the diluter 40 side is purged by the purge valve 42,
It is supplied to the processing mechanism 46 through the line 44 and is subjected to detoxification processing.

In the diluter 40, a diluting process is performed in a manner described later, and the sample gas G is supplied to the gas chromatograph analyzer 20 through the supply line IL. Here, reference numeral 48 is an instrumentation air source, 50 is an inert gas source, 52
Indicates a vacuum pump for vacuuming. The gas that has not been supplied to the analyzer 20 as the sample gas G is sent to the processing mechanism 46 via the line 54 and is subjected to the detoxification process as described above.

The sample gas G analyzed by the analyzer 20 and the unnecessary sample gas G used for purging the sample gas injection device 2 (FIG. 1) are exhaust lines OL, OL-2 (see FIG. 1; In FIG. 5, the lines are collectively represented by one line) and are sent to the processing mechanism 46 for detoxification processing.

Next, the diluter 40 will be described with reference to FIG. At the stage before dilution, the raw material gas cutoff valve A
V-6, AV1-A, raw material gas injection flow rate adjusting valve PCV-
1, raw material gas injection valve AV1-B, vent valve AV-3, vacuum gauge protection valve AV-4, vacuum suction valve AV-5, inert gas injection flow rate adjusting valve PCV-2, inert gas injection valve AV2-
A, sample gas supply valve AV2-B, sample gas pressure reducing valve REG
-1, Sample gas supply valve MV-3 are all closed. On the other hand, the source gas introduction valve MV-1 and the inert gas introduction valve MV-2 are normally open. In addition, in FIG.
V-1 is a vent check valve, PG-1 is a source gas pressure indicator, PT-1 and PT-2 are pressure converters, PG-2 is an inert gas pressure indicator, and CV-2 is an inert gas reverse valve. Stop valve, R
EG-2 is an instrumentation air pressure reducing valve, PG-3 is an instrumentation air pressure indicator, SL is a cylinder (for example, a capacity of 50 in FIG. 6).
0CC).

In this state, the vacuum gauge protection valve AV-4 and the vacuum suction valve AV-5 are opened and the vacuum pump 52 is operated to perform vacuum suction in the cylinder SL. Then, the raw material gas injection valve AV1-B, the raw material gas cutoff valve AV1-A, AV
-6. The raw material gas injection flow rate adjusting valve PCV-1 is opened to reduce the pressure in the cylinder SL to 0.1 Torr. Then, among the valves opened at this stage, the vacuum gauge protection valve AV-
Close valves other than 4 again. Then, the source gas is injected up to the set pressure.

When the source gas is injected up to the set pressure, the source gas injection valve AV1-B, the source gas cutoff valve AV1-A,
AV-6 is opened, and raw material gas injection flow rate adjusting valve PCV-1
The raw material gas is injected while squeezing. And the pressure transducer P
The output of T-1 is checked, and the opening of the raw material gas injection flow rate adjusting valve PCV-1 is reduced as the pressure approaches the set pressure PSOURCE. Then, when the set pressure PSOURCE is reached, the adjustment valve PCV-1, valves AV-6, AV1-A, AV
1-B is closed. The control method of the opening degree of the adjusting valve PCV-1 is, for example, the PID control method.

Next, an inert gas is injected into the cylinder SL. In that case, first, the valve AV2-A and the adjusting valve PCV-
2 is opened, the output of the pressure converter PT-2 is checked, and the opening of the regulating valve PCV-2 is narrowed. Here, the control method of the opening degree of the regulating valve PCV-2 is, for example, the PID control method. Then, when the inert gas injected into the cylinder SL reaches the set pressure PN2, the regulating valve PCV-
2. Close the valve AV2-A. As a result, the source gas is diluted with PN2 / PSOURCE times, and becomes a properly diluted sample gas (reference numeral G in FIG. 1-5).

Next, the sample gas G is supplied to the gas chromatograph analyzer 20 through the supply line IL. At this time, the valves AV2-B and MV-3 are opened, and the sample gas pressure reducing valve REG-1 is set to a predetermined supply pressure.

For undiluted gas, valve A
It is discharged to the line 54 via V-3 and CV-1.

[0039]

The effects of the present invention are listed below.

(1) Even if the sample gas (toxic gas) leaks, since it is surrounded by the closed case (purge case), there is no risk of diffusion into the atmosphere and no risk of causing environmental pollution.

(2) A purge gas such as an inert gas is supplied into the closed case (purge case) to function to purge unnecessary oxygen and moisture, and the inert gas is mixed in the system. However, it does not react with the sample gas or the like, and there is no fear of clogging of the pipe due to compound formation.

(3) Since the carrier gas supplied can be analyzed with almost no passage through the joint, etc., based on the analysis results, is it possible that moisture and oxygen enter and mix from the joint, etc.? Whether or not it can be determined. Further, the sample gas remaining in the system through which the sample gas passes can be purged with the carrier gas, and it can be determined whether or not the purging is sufficient.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of FIG. 1 in a further simplified form.

FIG. 3 is a block diagram showing a conventional gas chromatograph analyzer.

FIG. 4 is a block diagram showing a simplified configuration of the conventional gas chromatograph analyzer shown in FIG.

FIG. 5 is a block diagram showing a connection mode between a gas chromatograph analysis device and a diluter.

FIG. 6 is a block diagram illustrating details of the diluter shown in FIG.

[Explanation of symbols]

 G ... Sample gas IL ... Supply line 1 ... Solenoid valve 2 ... Sample gas injection device 3 ... Entry side joint 4 ... Specimen pole column 5 ... Exit side joint 6 ...・ Detector 8 ・ ・ ・ Recorder OL, ROL, OL-2 ・ ・ ・ Exhaust line 9 ・ ・ ・ Carrier gas cylinder 10 ・ ・ ・ Reducing valve 11 ・ ・ ・ Drying agent container 12, 22 ・ ・ ・ Three-way joint 14 ・・ ・ Inlet side joint 15 ・ ・ ・ Control electrode column 16 ・ ・ ・ Ejection side joint GL ・ ・ ・ Sample electrode side line RL ・ ・ ・ Control electrode side line 18 ・ ・ ・ Constant temperature bath 19 ・ ・ ・ Power supply 20 ・ ・ ・Gas chromatograph analyzer 24 ... 3-way cock 26 ... Purge case 28 ... Purge gas supply port 30 ... Discharge port 32 ... Electromagnetic valve S ... Source gas generation source OG ... Source gas generation Gas generated from the source 38 ... Main valve 39 ... Line 40 ... Diluter 42 ... Purge valve 44, 54 ... Line 46 ... Processing mechanism 48 ... Instrumentation air source 50 ... Inert Gas source 52 ... Vacuum pump for vacuuming AV1-A, AV-6 ... Raw material gas shutoff valve PCV-1 ... Raw material gas injection flow rate control valve AV1-B ... Raw material gas injection valve AV- 3 ... Vent valve AV-4 ... Vacuum gauge protection valve AV-5 ... Vacuum suction valve PCV-2 ... Inert gas injection flow rate adjustment valve AV2-A ... Inert gas injection valve AV2 -B ... Sample gas supply valve REG-1 ... Sample gas pressure reducing valve MV-3 ... Sample gas supply valve MV-1 ... Source gas introduction valve MV-2 ... Inert gas introduction valve CV-1 ... Vent check valve PG-1 ... Raw material gas pressure indicator PT-1, PT- 2 ... Pressure converter PG-2 ... Inert gas pressure indicator CV-2 ... Inert gas check valve REG-2 ... Instrumentation air pressure reducing valve PG-3 ... Instrumentation Air pressure indicator SL ・ ・ ・ Cylinder

Claims (3)

[Claims] 1. A gas chromatograph analyzer including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, wherein the two systems are enclosed by a sealed case, and the atmosphere in the case is replaced by a purge gas. A gas chromatograph analyzer characterized by being equipped with a purging mechanism for performing. 2. A gas chromatograph analyzer including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, and a branch mechanism for branching a branch system from the system through which the carrier gas passes and a branch system. A gas chromatograph analyzer, comprising: a connection mechanism connected to a system through which the sample gas passes. 3. A gas chromatograph analyzer including a system through which a sample gas to be analyzed passes and a system through which a carrier gas passes, wherein the two systems are surrounded by a sealed case, and the atmosphere in the case is replaced with a purge gas. A gas chromatograph analysis apparatus, comprising: a purging mechanism for operating the carrier gas, a branch mechanism for branching a branch system from a system through which a carrier gas passes, and a connection mechanism for connecting the branch system to a system through which a sample gas passes.