TWI669497B - Gas analyzing device and method for gas analysis - Google Patents

Abstract

The present invention provides an apparatus and method for analyzing residual gas with high sensitivity regardless of the amount of residual gas in the test body.

The apparatus of the present invention comprises: a sample chamber 1 for taking out residual gas from the test body 3 in a vacuum; an intermediate chamber 4 connected to the sample chamber 1 through a first vacuum valve in a vacuum; a first analysis chamber 6, in a vacuum state Connected to the intermediate chamber 4 through a second vacuum valve; the second analysis chamber 7 is connected to the intermediate chamber 4 through the orifice plate 5 in a vacuum state; a vacuum gauge measures the amount of gas in the sample chamber 1; The second analysis chamber 7 releases the residual gas; the control calculation unit 9 closes the second vacuum valve when the gas amount is above the threshold value, and opens the second vacuum valve when the gas amount does not reach the threshold value; and one or more mass analysis The residual gas acquired to the second analysis chamber 7 is analyzed when the gas amount is above the threshold, and the residual gas acquired to the first analysis chamber 6 is analyzed when the gas amount does not reach the threshold.

Description

Gas analysis device and gas analysis method

The present invention relates to a gas analysis device and a gas analysis method.

The residual gas of the test body such as a hermetically sealed semiconductor package and a hermetically sealed hollow semiconductor package such as a lamp is generally subjected to composition analysis using a mass spectrometer in a vacuum. In the sealing structure of the test body, the amount of residual gas in the test body may vary due to leakage of residual gas or detachment of gas from the use of the material. Therefore, the amount of residual gas in the test body cannot be known without opening the seal without breaking the seal structure.

Further, when a large amount of gas is introduced into the analysis chamber having the mass spectrometer, the upper limit of the operating pressure is exceeded. Therefore, if the amount of residual gas is large, the composition analysis of the residual gas cannot be performed. Also, if the amount of residual gas is too large, the mass spectrometer may malfunction.

In order to cope with a large amount of residual gas, it is considered that when the residual gas is taken into the analysis chamber, an orifice plate is provided at the inlet of the analysis chamber to reduce the amount of residual gas entering the analysis chamber. Because the residue is passed through the orifice plate The gas flows into the analysis chamber in sequence, so it is necessary to timely release the residual gas from the outgas portion from the analysis chamber. The amount of residual gas retained in the analysis chamber can be controlled by the orifice plate and the venting portion.

For example, Patent Document 1 discloses a technique in which an orifice plate is provided between a sample chamber and an analysis chamber to analyze a residual gas flowing into an analysis chamber having a mass spectrometer.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-180581

As described above, the amount of residual gas retained in the analysis chamber can be controlled by the orifice plate and the gas release portion, but when the residual gas is small, the orifice plate can reduce the amount of residual gas reaching the mass spectrometer to the specific mass. The lower limit of the measurement of the analyzer is small, or the trace residual gas reaching the analysis chamber is released from the gas release portion before being analyzed by the mass spectrometer.

Therefore, when the amount of residual gas is small, composition analysis may be impossible or the analysis efficiency may be low. On the other hand, if the orifice plate or the gas release portion is not provided, as described above, a large amount of residual gas may not be able to correspond. An object of the present invention is to analyze residual gas with high sensitivity regardless of the amount of residual gas in the test body.

In order to solve the above problems, the present invention includes a sample chamber. The residual gas is taken out from the test body in a vacuum; the intermediate chamber is connected to the sample chamber in a vacuum through the first vacuum valve in such a manner as to obtain residual gas from the sample chamber; the first analysis chamber is in a vacuum state, Connecting to the intermediate chamber through a second vacuum valve in such a manner as to obtain residual gas from the intermediate chamber; the second analysis chamber is connected to the intermediate chamber through the orifice plate in a vacuum state in such a manner as to obtain residual gas from the intermediate chamber; a vacuum gauge for measuring the amount of gas of the residual gas in the sample chamber; a gas release portion for releasing the residual gas from the second analysis chamber; and a control calculation unit that closes the second vacuum valve when the gas amount is above a threshold value, and When the amount of gas does not reach the threshold, the second vacuum valve is opened, and after the vacuum gauge measures the amount of residual gas, the first vacuum valve is opened; and one or more mass spectrometers, when the gas amount is above the threshold, the analysis is obtained. The residual gas to the second analysis chamber, and when the amount of gas does not reach the threshold, the residual gas obtained to the first analysis chamber is analyzed.

According to the present invention, the residual gas can be analyzed regardless of the amount of residual gas in the test body.

1‧‧‧ sample room

2‧‧‧Opener

3‧‧‧Test body

4‧‧‧Intermediate room

5‧‧‧ orifice plate

6‧‧‧First Analysis Room

7‧‧‧Second analysis room

8‧‧‧Detonation Department

9‧‧‧Control and Calculation Department

10‧‧‧Communication pathway

12‧‧‧Variable orifice plate

13‧‧‧孔口

14‧‧‧ center axis

15‧‧‧ Cover

100, 200, 300‧‧‧ gas analysis device

201‧‧‧ input interface

202‧‧‧calculation device

203‧‧‧ memory device

204‧‧‧ Output interface

G0, G1, G2‧‧‧ vacuum gauge

MS1, MS2‧‧‧ quality analyzer

S101 to S114, S201, S202, S301, S302‧‧‧ steps

VV1, VV2, VV3‧‧‧ vacuum valve

Fig. 1 is a schematic view showing one of the constitutions of the gas analyzer according to the first embodiment of the present invention.

Fig. 2 is a schematic view showing the configuration of a control calculation unit.

Fig. 3 is a flow chart showing a gas analysis method using a gas analyzer in the first embodiment of the present invention.

Figure 4 is a diagram showing gas analysis in Embodiment 1 of the present invention. A graph of a relationship between the pressure of the sample chamber of the apparatus and the pressure of the first analysis chamber immediately after opening the vacuum valve.

Fig. 5 is a graph showing an example of temporal changes in pressure in the first analysis chamber before and after opening and closing of the vacuum valve in the gas analysis apparatus according to the first embodiment of the present invention.

Fig. 6 is a graph showing an example of temporal changes in pressure in a second analysis chamber before and after opening and closing of a vacuum valve in the gas analysis apparatus according to the first embodiment of the present invention.

Fig. 7 is a schematic view showing the configuration of a gas analyzer according to a second embodiment of the present invention.

Fig. 8 is a flow chart showing a gas analysis method using a gas analysis device according to Embodiment 2 of the present invention.

Fig. 9 is a schematic view showing the configuration of a gas analysis device according to Embodiment 3 of the present invention.

Fig. 10 is a schematic view showing the configuration of a variable orifice plate used in the gas analyzer according to the third embodiment of the present invention.

Fig. 11 is a flow chart showing a gas analysis method using the gas analysis device according to Embodiment 3 of the present invention.

Figure 12 is a view showing a variable orifice in the time change of the pressure in the first analysis chamber before and after the vacuum valve is opened and closed in the gas analysis device according to Embodiment 3 of the present invention. A chart of one example of the number of aperture openings in a plate.

Figure 13 is a view showing a gas analysis device according to Embodiment 3 of the present invention, before the vacuum valve is opened and closed, when the gas analysis is performed in the second analysis chamber. Thereafter, a graph of an example of the number of orifice plate openings of the variable orifice plate in the time change of the pressure in the first analysis chamber.

Hereinafter, a gas analysis device according to an embodiment of the present invention will be described in detail based on the drawings. Further, the present invention is not limited by the embodiment.

Embodiment 1.

The gas analyzer 100 of the present invention analyzes the composition of the residual gas sealed in the sample. In addition, the drawings used are not intended to represent actual dimensions or proportions of the invention, but are used to illustrate the invention.

Fig. 1 is a schematic view showing the configuration of a gas analysis device 100 according to Embodiment 1 of the present invention. As illustrated in Fig. 1, the gas analysis device 100 of the present embodiment is substantially composed of a sample chamber 1 and a first analysis chamber 6 and a second analysis chamber 7, an intermediate chamber 4, an orifice plate 5, an outgassing portion 8, and a control calculation. Part 9 is composed. The details of the configuration are as follows.

The sample chamber 1 has a sealer 2 for opening the test body 3 placed in the sample chamber 1, a vacuum gauge G0, and a vacuum valve VV1. The sample chamber 1 is connected to the intermediate chamber 4 through a vacuum valve VV1. The vacuum gauges G0, G1, and G2 are, for example, a spinning rotor gauge, a diaphragm vacuum gauge, and a crystal gauge.

Moreover, the vacuum gauges G0, G1, G2 have, for example, a cold cathode ionization gauge or a B-A (Bayard-Alpert). An ionization vacuum gauge such as a vacuum gauge, or a composite vacuum gauge combined with an ionization vacuum gauge such as a crystal vacuum gauge and a cold cathode vacuum gauge. The vacuum gauges G0, G1, and G2 measure the pressure.

The vacuum gauge G0 measures the pressure in the sample chamber 1. The vacuum valve VV1 uses, for example, a gate valve. The vacuum valve VV1 blocks and opens the space between the sample chamber 1 and the intermediate chamber 4 by opening and closing the valve.

Here, the test body 3 is intended to have a hollow structure, a semiconductor device having a volume of less than 5 mm ^{3 in} the hollow structure, or a so-called MEMS (Micro Electro Mechanical Systems). Here, the opening of the test body 3 means that the residual gas of the test body 3 is released into the sample chamber 1 by the destruction of the test body 3.

The intermediate chamber 4 is provided with a vacuum valve VV1, a vacuum valve VV2, and an orifice plate 5, and is connected to the vacuum chamber VV1 so that residual gas can be obtained from the sample chamber 1. Further, the intermediate chamber 4 is connected to the first analysis chamber 6 through the vacuum valve VV2, and is connected to the second analysis chamber 7 through the orifice plate 5. The orifice plate 5 has a function of reducing the flow of residual gas. The orifice plate 5 can be, for example, a cylindrical shape in which a small hole is formed in a metal plate. For example, a gate valve can be used as the vacuum valve VV2.

The vacuum valve VV2 performs the opening and closing of the valve to block the space between the first analysis chamber 6 and the intermediate chamber 4 and the open vacuum valve, and it is desirable to open the vacuum valve by the control calculation unit 9, The size of the vacuum valve is such that the intermediate chamber 4 and the first analysis chamber 6 appear to be a large space.

The first analysis room 6 is equipped with a vacuum gauge G1 and mass analysis Count MS1. The first analysis chamber 6 is connected to the intermediate chamber 4 by means of the vacuum valve VV2 so that the residual gas from the intermediate chamber 4 can be obtained. The vacuum gauge G1 measures the pressure in the first analysis chamber 6. The vacuum gauge G1 can be, for example, a cold cathode vacuum gauge or a B-A vacuum gauge, an ion gauge of a nude gauge or the like.

The residual gas system liberated from the inside of the test body 3 passes through the vacuum valve VV1 and the intermediate chamber 4, and enters the first analysis chamber 6 through the vacuum valve VV2. Then, the mass spectrometer MS1 measures and analyzes the residual gas that is taken to the first analysis chamber 6.

The mass spectrometers MS1, MS2 are, for example, quadrupole mass spectrometers. Here, the mass spectrometers MS1 and MS2 are expected to determine the pressure with an upper limit during use, and are not suitable for measurement and analysis of a large amount of gas. The mass spectrometers MS1 and MS2 may cause malfunctions because a large amount of gas is pressurized in the atmosphere.

Further, in the present embodiment, the number of the mass spectrometers is not limited to the mass spectrometer MS1 included in the first analysis chamber 6, and the mass spectrometer MS2 included in the second analysis chamber 7. The residual gas obtained to the first analysis chamber and the residual gas obtained to the second analysis chamber may also be measured and analyzed by a mass spectrometer. Further, the position of the mass spectrometer is not particularly limited as long as the residual gas obtained in the first analysis chamber and the residual gas obtained in the second analysis chamber can be measured and analyzed.

The second analysis chamber 7 is connected to a vacuum gauge G2, a mass spectrometer MS2, and an outgassing portion 8. The second analysis chamber 7 is obtained by the orifice plate 5 The residual gas from the intermediate chamber 4 is connected to the intermediate chamber 4. The vacuum gauge G2 measures the pressure in the second analysis chamber 7. An ionization vacuum gauge such as a B-A vacuum gauge or a bare gauge can be used as the vacuum gauge G2.

The vacuum gauge G2 may be any pressure measurement, and the vacuum gauges G0 and G1 may be of the same type or different types, and are not limited. In the present embodiment, the pressure of the residual gas is measured, but the amount of gas can be measured. The mass spectrometer MS2 is provided for measuring the residual gas released from the inside of the test body 3, and measuring the residual gas introduced into the second analysis chamber 7 through the orifice plate 5 through the vacuum valve VV1 and the intermediate chamber 4.

The orifice plate 5 can reduce the amount of gas of the residual gas moving from the intermediate chamber 4 to the second analysis chamber 7. When the conductivity of the orifice plate 5 is too small, the amount of gas that moves through the orifice plate 5 to the second analysis chamber 7 decreases, and the measurement limit is exceeded. Therefore, the conductivity of the orifice plate 5 is preferably not too small.

The mass spectrometer MS2 is the same as the mass spectrometer MS1, and for example, a quadrupole mass spectrometer can be used. Here, it is expected that the mass spectrometer MS1 and the mass spectrometer MS2 have the same performance, but this is not limited thereto, and any one may be a component that can measure and analyze the residual gas, and may have a difference in performance.

The second analysis chamber 7 is connected to the gas release portion 8. The venting portion 8 is composed of a main venting portion and a sub-pump, and is, for example, a turbo-molecular pump using a rotary pump as a submersible pump. Further, in addition to the turbomolecular pump, the deflation portion 8 also uses an outgassing portion 8 using a NEG (Non Evaporated Getter) pump or an ion pump.

The residual gas system flowing from the sample chamber 1 through the orifice plate 5 to the second analysis chamber 7 by the gas release portion 8 is released from the second analysis chamber 7. By combining the venting portion 8 and the orifice plate 5, the flow rate of the residual gas released from the sample chamber 1 and the intermediate chamber 4 can be controlled. Before the start of the test, the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7 can be evacuated by opening and releasing the entire vacuum valve of the gas analysis device 100. The term "vacuum" as used herein refers to a vacuum defined by JIS.

The mass spectrometer MS1 and the mass spectrometer MS2 used in the first analysis chamber 6 and the second analysis chamber 7 are connected to a control calculation unit 9 having a function of controlling the operation of the mass spectrometer and an arithmetic function for processing the obtained data. The detectors of the mass spectrometers MS1, MS2 are, for example, Faraday cups or secondary electron multiplier tubes. In addition, the upper limit of the analytical chamber measurable by the Faraday cup is about 0.01 Pa to 0.001 Pa. The upper limit of the analytical chamber pressure measurable by the secondary electron multiplier tube is about 0.001 Pa to 0.0001 Pa.

As a mass spectrometer, a representative has a quadrupole mass spectrometer, but when measuring a mass-to-charge ratio of a complex number, since the measurement period actually takes a few seconds, if the residual gas is removed from the analysis chamber for a shorter period of time than the measurement period, The mass analyzer will not be able to measure the mass-to-charge ratio.

The mass spectrometer MS1 must measure at least one residual gas of the eye between the residual gas from the first analysis chamber 6 when it is released. When the test body 3 is opened, when the residual gas is minute, it is desirable to increase the residence time of the residual gas in the first analysis chamber 6. According to the configuration of the first embodiment, the first analysis chamber 6 can pass through the orifice plate 5 from the first analysis chamber. 6 The amount of residual gas released from the gas becomes small. And, as previously described, the mass spectrometer MS1, the mass spectrometer MS2 have been determined to use the medium upper limit pressure.

Further, the vacuum gauges G0, G1, and G2 of the gas analyzer 100, and the mass spectrometers MS1 and MS2, and the vacuum valves VV1 and VV2 are electrically connected to the control calculation unit 9 via the communication path 10, respectively. The control calculation unit 9 can calculate the measurement data acquired by the vacuum gauges G0, G1, and G2 and the mass spectrometers MS1 and MS2, and control the opening and closing operations of the vacuum valves VV1 and VV2.

Fig. 2 is a schematic view showing the configuration of the control calculation unit 9. The control calculation unit 9 includes vacuum gauges G0, G1, G2, a receiving unit, a memory unit, a calculation unit, a determination unit, and a transmission unit that receives measurement data from the mass spectrometers M1 and M2; the memory The calculation unit receives the measurement data; the calculation unit calculates the measurement data; the determination unit determines the opening and closing of the vacuum valves VV1 and VV2; and the transmission unit transmits an opening and closing command for opening and closing the operation of the vacuum valves VV1 and VV2 to the vacuum valve. VV1, VV2.

The processing of the calculation unit or the determination unit is realized by the calculation device 202 such as a CPU, and the memory unit is realized by the memory device 203 such as a memory, an HDD or an SSD. The receiving unit is implemented by an input interface (IF) 201, and the transmitting unit is implemented by an output interface (IF) 204. The control calculation unit 9 is connected to the vacuum gauges G0, G1, G2, the mass spectrometers MS1, MS2, the vacuum valves VV1, VV2, and the like via the communication path 10.

Fig. 3 is a flow chart showing a gas analysis method using the gas analysis device 100. The analysis sequence of the residual gas of the test body 3 will be described along the flowchart of Fig. 3. According to the first embodiment, the first analysis is performed. Which of the chamber 6 or the second analysis chamber 7 measures the partial pressure is selected in accordance with the pressure value (vacuum gauge G0) in the sample chamber 1 when the test body 3 is opened. Thereby, it becomes possible to analyze the residual gas inside the hermetic sealing device in response to a wider range of pressures.

First, the sample chamber 1 is opened to the atmosphere, and the test body 3 belonging to the hermetic sealing device is placed in the sample chamber 1 (step S101). Each of the spaces (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) in the apparatus are all open to the atmosphere, and the gas release portion 8 is stopped, and the state in which the vacuum valves VV1 and VV2 are opened is set to Initial state. In the initial state, the test body 3 is placed inside the sample chamber 1. In the present embodiment, the entire space atmosphere is opened, but this is not limited thereto. When the test body 3 is provided, at least the sample chamber 1 may be opened to the atmosphere.

After the test body 3 is installed, the gas release unit 8 is activated in a state where the vacuum valves VV1 and VV2 of the gas analysis device 100 are all turned on, and all the spaces (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) The vacuum outgassing is started (step S102). The air release unit 8 is used to degas all the spaces in the apparatus (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7). Here, the outgassing system is sufficiently performed until the pressure of the background of all the spaces (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) is stabilized (step S103).

When all of the space (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) is completed, the vacuum valve VV1 is closed to isolate the sample chamber 1 from the intermediate chamber 4 (step S104). Using the unsealing device 2, the sealing structure of the test body 3 is broken and unsealed (step S105). Encapsulation test body 3 The internal residual gas instantaneously diffuses to the sample chamber 1. The pressure of the diffused residual gas was measured by a vacuum gauge G0.

Here, the volume inside the sample chamber 1 is V ₀ , and the pressure inside the sample chamber 1 before the test body 3 is opened is p ₀ , and the pressure after the opening of the test body 3 is measured by the vacuum gauge G0. In the case of P ₀ , the gas amount Q of the residual gas enclosed in the test body 3 is represented by Q = V ₀ × (P ₀ - p ₀ ).

The p ₀ system can be roughly estimated by the buildup method. For example, before the sealing structure of the test body 3 is destroyed, in the gas analyzer 100 after vacuum gassing, the value of the vacuum gauge G0 when the vacuum valve VV1 is closed, that is, the sample chamber 1 without residual gas The pressure is the background pressure set to p ₀ .

Further, at this time, when the volume of the test body 3 is V _s , the pressure of the residual gas of the test body 3 is P _s , and when the test body 3 is opened, the pressure P _{0 of the} sample chamber 1 and the test body 3 are The pressure of the residual gas is expressed by P _s = (V ₀ /V _s ) × P ₀ . That is, the gas amount Q of the residual gas and the pressure P _{s of the} residual gas can be known from the pressure P _{0 of the} sample chamber 1.

The selection of the residual gas measurement in the first analysis chamber 6 or the second analysis chamber 7 is determined based on the gas amount Q of the residual gas. Although the amount of gas is Q here, it is not limited thereto. In the present embodiment, the selection of the analysis chamber may be performed based on the pressure of the residual gas, and is not particularly limited. When the pressure p ₀ of the background of the sample chamber 1 is very small (P ₀ >>p ₀ ) compared with P ₀ , the pressure P _{0 of the} sample chamber 1 can be regarded as (P ₀ -p ₀ )≒P ₀ . sample chamber volume V ₀ 1 is constant, the amount of gas remaining gases Q may be a pressure sample chamber of 1 P ₀ is uniquely determined based, it can be a first analysis chamber 6 and a second analysis chamber 7 based on the pressure P ₀ of select.

In the gas analyzer 100 of the present invention, based on the value of the pressure P ₀ of the sample chamber 1 at the time of opening the test body 3, the analysis of the residual gas is performed by using the first analysis chamber 6 or the second analysis chamber 7 (step S106). . In the following, in the determination of the switching of the analysis chamber, the determination method based on the measurement value of the vacuum gauge G0 (the pressure P _{0 of the} sample chamber 1) is used instead of the gas amount Q. Further, in the apparatus of the present invention, the volume V _{0 of the} sample chamber 1 and the volume of other spaces are constant.

The value of the vacuum gauge G0 measured by the sample chamber 1 is sent to the control calculation unit 9. The control calculation unit 9 performs opening and closing control of the vacuum valve VV2 based on the value of the received vacuum gauge G0. When the value of the vacuum gauge G0, that is, the pressure P ₀ of the sample chamber 1 is equal to or greater than the threshold value P ₀ ^* , the control calculation unit 9 closes the vacuum valve VV2 located between the first analysis chamber 6 and the intermediate chamber 4 (step S107). The first analysis chamber 6 is isolated from the intermediate chamber 4. Then, the control calculation unit 9 opens the vacuum valve VV1 between the sample chamber 1 and the intermediate chamber 4 (step S108), and the mass analyzer MS2 of the second analysis chamber 7 measures and analyzes the residual gas sealed to the test body 3 (step S109). ).

When the test body 3 is opened, the pressure P ₀ is equal to or greater than the threshold value P ₀ ^* , that is, when the gas amount Q (pressure) of the residual gas is large, the residual gas moves through the orifice plate 5 through the intermediate chamber 4 to the second analysis. The chamber 7 measures and analyzes the residual gas using the mass spectrometer MS2 of the second analysis chamber 7. At this time, the pressure in the second analysis chamber 7 must not be higher than the pressure of the upper limit of the use of the mass spectrometer MS2.

In the gas analyzer 100, the residual gas of the test body 3 is gradually flowed into the second analysis chamber 7 through the orifice plate 5, and the residual gas system that has flowed through the orifice plate 5 continuously releases the gas to the gas release portion 8 to suppress the gas. The pressure caused by the residual gas in the analysis chamber 7 rises. By this mechanism, the pressure of the residual gas in the second analysis chamber 7 can be kept smaller than the upper limit of the upper limit of the mass spectrometer MS2, and even if the amount of residual gas in the test body 3 is large, mass analysis can be performed. Count MS2 measurement.

When the value of the vacuum gauge G0, that is, the pressure P _{0 of the} sample chamber 1 does not reach the threshold value P ₀ ^* , the control calculation unit 9 opens the vacuum valve VV2 between the first analysis chamber 6 and the intermediate chamber 4, or remains open. The vacuum valve VV1 interposed between the sample chamber 1 and the intermediate chamber 4 is opened (step S110). The residual gas is diffused from the intermediate chamber 4 to the first analysis chamber 6 by opening the vacuum valve VV1. Then, the residual gas is measured and analyzed by the mass spectrometer MS1 of the first analysis chamber 6 (step S111).

When the test body 3 is opened, the pressure P _{0 does} not reach the threshold value P ₀ ^* , that is, the gas amount Q (pressure) of the residual gas is small, and the residual gas system moves from the intermediate chamber 4 to the first analysis chamber 6 through the vacuum valve VV2. The residual gas was measured and analyzed using the mass spectrometer MS1 of the first analysis chamber 6. At this time, the pressure in the first analysis chamber 6 must also be higher than the pressure of the upper limit of the use of the mass spectrometer MS1. However, the threshold value of not reaching P ₀ ^* is expected to be smaller than the upper limit of the use limit of the mass spectrometer MS1, and the residual gas introduced into the first analysis chamber 6 may not exceed the pressure of the upper limit of the use of the mass spectrometer MS1. The details are as described later.

The residual gas flows into the first point through the vacuum valve VV2 Analysis chamber 6. The inner diameter of the piping of the vacuum valve VV2 and the diameter of the vacuum valve are much larger than the inner diameter of the orifice plate 5. Therefore, the number of gas molecules moving to the first analysis chamber 6 is larger than that of the gas molecules that are released from the intermediate chamber 4 through the orifice plate 5, so that it can be measured by the mass spectrometer MS1.

On the other hand, the second analysis chamber 7 is provided with the deflation portion 8, so that the residual gas moved to the intermediate chamber 4 and the first analysis chamber 6 is slowly passed to the second analysis chamber 7 through the orifice plate 5 of the intermediate chamber 4. Moving, further outgassing by the venting section 8.

In the present embodiment, it is assumed that the deflux portion 8 also continuously operates when the pressure P _{0 does} not reach the threshold value P ₀ ^*. However, the present invention is not limited thereto, and the control calculation unit 9 determines that the pressure P _{0 does} not reach the threshold value P ₀ ^* . It is also possible to control so as to stop the operation of the air release unit 8.

The measurement is performed after the measurement or analysis by any of the mass spectrometer MS1 or the mass spectrometer MS2 is completed (step S112). When the measurement is completed, the control calculation device 9 closes the vacuum valve VV1 (step S113), and opens the atmosphere of the sample chamber 1 so that the test body 3 can be taken out (step S114). Next, the threshold P ₀ ^{* will} be described. The threshold value P ₀ ^* is determined based on the relationship between the pressure of the sample chamber 1 and the pressure of the first analysis chamber 6.

Here, the volume of the first analysis chamber 6 is V ₁ , the volume of the intermediate chamber 4 is V _c , and the pressure of the first analysis chamber when the sample chamber 1 and the vacuum valves VV1 and VV2 are opened is P ₁ , P ₁ It is expressed as P ₁ =(V ₀ /(V ₀ +V _c +V ₁ ))×P ₀ .

That is, a pressure gauge in the mass spectrometer MS1 is operable upper limit of P _qms, the vacuum valve VV1, VV2 open occasion, a first analysis chamber 6 of the pressure P ₁ becomes the upper limit of operation pressure gauge MS1 mass spectrometry of P _qms When the pressure P _{0 of the} sample chamber 1 is P ₀ ^* , P ₀ ^* is expressed as P ₀ ^* = ((V ₀ + V _c + V ₁ ) / V ₀ ) × P _qms .

Therefore, by setting the threshold value to P ₀ ^* , when the pressure of the residual gas does not exceed the upper limit of the operating pressure of the mass spectrometer MS1, the gas analyzer 100 can be measured by the mass spectrometer MS1 of the first analysis chamber 6, In the analysis, when the upper limit of the operating pressure is exceeded, the gas analyzer 100 can reduce the amount of gas (pressure) of the residual gas and measure and analyze it by the mass spectrometer MS2 of the second analysis chamber 7.

Here, as an example, P ₀ ^* calculated based on the upper limit P _qms of the operating pressure of the mass spectrometer is set as a threshold value, but is not limited thereto. The threshold value may be a value set in time according to a user who uses the gas analysis device 100, and may be, for example, P ₀ ^* obtained by a pressure of Pqms or less.

Fig. 4 is a graph showing an example of the relationship between the pressure of the sample chamber 1 of the gas analysis device 100 and the pressure of the first analysis chamber 6 immediately after the vacuum valve VV1 is opened. The horizontal axis of Fig. 4 shows the pressure P ₀ of the sample chamber 1 after the test body 3 is opened, and the vertical axis indicates the pressure P ₁ of the first analysis chamber 6 when the vacuum valve VV1 of the test body 3 is opened. Plotted lines in FIG. 3 shows an example of relations between each of P ₀ P ₁ on the occasion of the opening with respect to the test sample.

In the gas analyzer 100 of the present invention, the relationship between P ₀ and P ₁ is the volume V _{0 of the} sample chamber 1 and the volume V _{c of the} intermediate chamber 4, the volume V _{1 of the} first analysis chamber 6, and the hollow of the test body 3. When the internal volume V _s is constructed, it is represented by P ₁ = (V ₀ / (V ₀ + V _c + V ₁ )) × P ₀ . In the relationship between P ₀ and P ₁ in Fig. 4, if the upper limit pressure P _{qms of the} mass spectrometer MS1 is determined, the pressure P _{0 of the} sample chamber 1 of the analysis chamber to be used for determining the gas analysis can be uniquely determined. The threshold P ₀ ^* .

Fig. 5 is a graph showing an example of a temporal change in pressure of the vacuum valve VV1 in the first analysis chamber 6 before and after opening and closing in the gas analysis device 100, when the gas analysis is performed in the first analysis chamber 6. When the vacuum valve VV1 is opened, the residual gas diffused in the test body 3 is instantaneously diffused into the intermediate chamber 4, and further diffused to the first analysis chamber 6 (in a state where the vacuum valve VV2 is opened).

Due to the residual gas diffused to the test body 3 of the first analysis chamber 6, the pressure in the first analysis chamber 6 increases. The pressure is measured by the vacuum gauge G1, and the measured pressure and the ion intensity of each mass-to-charge ratio measured by the mass spectrometer MS1 are input to the control calculation unit 9 and calculated, and the control calculation unit 9 obtains the residual gas of the test body 3. Partial pressure and composition.

For example, in the first analysis chamber 6, when the partial pressure of nitrogen as the residual gas is obtained, the first analysis chamber 6 is only filled with nitrogen gas, and the relationship with the detection intensity of the mass spectrometer MS1 is obtained according to the pressure change of the first analysis chamber 6. . Then, when the residual gas in which a plurality of types of gases are mixed is analyzed in the first analysis chamber 6, the nitrogen gas detection intensity at each time within the measurement data of the mass spectrometer MS1 can be obtained to obtain the partial pressure of the residual gas nitrogen. Variety.

The method of filling the first analysis chamber 6 with only nitrogen gas is not limited, and a mixed gas obtained by mixing a plurality of types of gases having a known partial pressure of nitrogen may be used to obtain a relationship between the partial pressure of nitrogen and the detection intensity of the mass spectrometer MS1. According to the mass analysis, the measurement data of MS1 is checked from nitrogen every time. The measured intensity gives a time change of the partial pressure of nitrogen of the residual gas.

Fig. 6 is a view showing the time of the pressure in the second analysis chamber 7 before and after opening and closing of the vacuum valve VV1 in the gas analysis apparatus 100 according to the first embodiment of the present invention, when the gas analysis is performed in the second analysis chamber 7. A chart of one of the changes. When the vacuum valve VV1 is opened, the residual gas diffused in the test body 3 in the sample chamber 1 is instantaneously diffused into the intermediate chamber 4. The residual gas moved to the intermediate chamber 4 is moved to the second analysis chamber 7 through the orifice plate 5 of the intermediate chamber 4.

Due to the internal gas moving to the test body 3 of the second analysis chamber 7, the pressure in the second analysis chamber 7 is increased. The pressure is measured by the vacuum gauge G2, and the measured pressure and the mass-to-charge ratio measured by the mass spectrometer MS2 are input to the control calculation unit 9 and calculated, and the control calculation unit 9 obtains the inside of the test body 3. The partial pressure and composition of the residual gas.

In the second analysis chamber 7, the partial pressure system is the same as in the case of the first analysis chamber 6. For example, if the partial pressure of nitrogen is obtained in relation to the detection intensity of the mass spectrometer MS2, by combining with the measurement data, nitrogen gas can be obtained. The time of partial pressure changes. For example, by introducing a nitrogen partial pressure into the sample chamber 1 into a known mixed gas, the measured value of the partial pressure of nitrogen in the second analysis chamber 7 measured by the vacuum gauge G2 can be obtained by using the mass spectrometer MS2. The value of the detected intensity of the obtained nitrogen gas was used to determine the relationship between the nitrogen gas and the detection intensity of the mass spectrometer MS2.

According to the present invention, analysis of the following two can be performed, that is, a small mold hole of less than 1 mm ³ as in a non-cooled infrared sensor or a vacuum sealed MEMS device, and a trace amount in the vacuum sealed test body 3 The analysis of the residual gas, the leakage in the sealed structure of the sample, or the pressure of the internal residual gas caused by the degassing of the internal material of the sealed structure for some reason. According to the present embodiment, the residual gas of the hermetic sealing device can be analyzed for a wide range of pressures that have not been conventionally used.

Embodiment 2.

In the present embodiment, the second analysis chamber 7 is connected to the first analysis chamber 6 by the vacuum valve VV3, and the second analysis chamber 7 does not have the mass spectrometer MS2, which is different from the first embodiment.

Fig. 7 is a schematic view showing the configuration of a gas analysis device 200 according to the second embodiment. As illustrated in Fig. 7, the gas analysis device 200 of the present embodiment is provided with a vacuum valve VV3 in the second analysis chamber 7, and the second analysis chamber 7 and the first analysis chamber 6 are compared with the gas analysis device 100 of the first embodiment. Connected through vacuum valve VV3. Further, the vacuum valve VV3 is connected to the control calculation device 9.

Further, the point in which the vacuum gauge G2 and the mass spectrometer MS2 provided in the second analysis chamber 7 in the first embodiment are omitted is different from the configuration of the first embodiment. The vacuum valve VV3 uses a gate valve. The vacuum valve VV3 blocks and opens the space of the first analysis chamber 6 and the second analysis chamber 7 by opening and closing the valve.

Further, in the second embodiment, the partial pressure measurement performed in the second analysis chamber 7 in the first embodiment can be performed by the vacuum valve opening and closing operation. It is possible to perform in the first analysis room 6. Therefore, the opening and closing method of the valve in the analysis sequence is different from that of the first embodiment.

In the second embodiment, only the above points are different from the first embodiment, and the present embodiment is basically the same as the first embodiment. Therefore, the same elements are denoted by the same reference numerals and their description will be omitted. Next, the analysis procedure of the residual gas of the test body 3 using the gas analysis device 200 in the second embodiment will be described along the flowchart of FIG.

Fig. 8 is a flow chart showing a gas analysis method using the gas analysis device 200 according to Embodiment 2. Here, only the flow different from the first embodiment will be described. Since the other descriptions are the same as those in the first embodiment, they are omitted. Specifically, since the second analysis chamber 7 does not have a mass spectrometer and a vacuum gauge, it is different from the first embodiment in that it is analyzed by the first analysis chamber 6 through the vacuum valve VV3.

Although the determination of the relationship between the pressure of the sample chamber 1 and the pressure of the first analysis chamber 6 is the same as that of the first embodiment in the selection of the analysis chamber, in the present embodiment, the operation method of the vacuum valve is Since the first embodiment differs, the description will be made.

The case where the measured value of the vacuum gauge G0 is equal to or greater than the threshold value P ₀ ^* will be described. When the value of the vacuum gauge G0, that is, the pressure P ₀ of the sample chamber 1 is equal to or greater than the threshold value P ₀ ^* , the control calculation unit 9 closes the vacuum valve VV2 between the first analysis chamber 6 and the intermediate chamber 4, and opens in the first analysis. The vacuum valve VV3 between the chamber 6 and the intermediate chamber 4 (step S201).

In this step S201, the control calculation device 9 performs control so as to open the vacuum valve VV3, but is not limited thereto, and has been opened. When the vacuum valve VV3 is activated, the opening control may not be performed. When the vacuum valve VV1 is opened (step S110), the residual gas diffused in the test body 3 in the sample chamber 1 is instantaneously diffused into the intermediate chamber 4.

The residual gas moved to the intermediate chamber 4 is moved to the second analysis chamber 7 through the orifice plate 5 of the intermediate chamber 4. Then, the residual gas in the test body 3 moved to the second analysis chamber 7 is diffused to the first analysis chamber 6 through the vacuum valve VV3, and the pressure in the first analysis chamber 6 is increased. This pressure is measured by a vacuum gauge G1. Further, the partial pressure of the residual gas of the test body 3 can be obtained by calculating the measured value obtained by the mass spectrometer MS1 and the vacuum gauge G1 by the control calculation unit 9.

The case where the measured value of the vacuum gauge G0 is smaller than the threshold P ₀ ^* will be described. When the threshold value P ₀ ^* is not reached, if the determination in step S106 is NO (No), the control calculation device 9 closes the vacuum valve VV3 (step S202). The space between the first analysis chamber 6 and the second analysis chamber 7 is blocked by closing the vacuum valve VV3.

Next, the control calculation device 9 turns on the vacuum valve VV1 (step S110). When the vacuum valve VV1 is opened, the residual gas diffused in the test body 3 in the sample chamber 1 passes through the intermediate chamber 4 and instantaneously diffuses to the first analysis chamber 6 (in a state where the vacuum valve VV2 is opened). The subsequent measurement and analysis processing of the transfer quality analyzer MS1 is the same as that of the first embodiment, and thus the description thereof will be omitted.

The effects of the present embodiment will be described below. The mass spectrometer of the second embodiment is one less than the vacuum gauge and the first embodiment. Since there are fewer instruments, it is possible to save space and reduce the frequency of maintenance.

Further, in the second embodiment, the vacuum valve VV3 functions as a bypass for the intermediate chamber 4 and the sample chamber 1, so that the vacuum is released from the vacuum after the test body 3 is installed. Opening the vacuum valve VV3 and the vacuum valve VV2 allows the first analysis chamber 6, the intermediate chamber 4, and the sample chamber 1 to be released more quickly. Further, in the present embodiment, a portion different from the first embodiment will be described. The other parts are the same as those in the first embodiment.

Embodiment 3.

This embodiment differs from the first embodiment in that the orifice plate 5 is a variable orifice plate 12 capable of changing conductivity. Further, by forming the orifice plate 5 as the variable orifice plate 12, a process different from that of the first embodiment is generated in the analysis, and therefore, the differences will be described.

Fig. 9 is a schematic view showing the configuration of a gas analysis device 300 according to the third embodiment. Compared with the gas analysis device 100 of the first embodiment, the gas analysis device 300 of the present embodiment shown in FIG. 9 does not include the orifice plate 5, and includes the variable orifice plate 12. Further, the point of increasing the process of adjusting the conductivity of the variable orifice plate 12 in the analysis sequence is different from that of the first embodiment.

The third embodiment differs from the first embodiment only in the above points, and the present embodiment is basically the same as the first embodiment in principle. Therefore, the same elements are denoted by the same reference numerals, and the description thereof will be omitted.

Fig. 10 is a schematic view showing the configuration of a variable orifice plate 12 used in the gas analysis device 300 according to the third embodiment. Variable orifice The plate 12 is provided, for example, such that the orifices 13 having small holes in the metal disk are arranged in a plurality of ways in the circumferential direction centering on the central axis 14 of the metal disk. In addition, the apertures of the apertures 13 may be identical or different.

The variable orifice plate 12 is provided with a cover 15 having a semicircular shape or a fan shape. The cover 15 is rotated about the central axis 14 and serves as a mechanism for blocking the opening 13. The control calculation unit 9 can change the number of blocks of the orifice 13 by controlling the rotation angle of the cover 15, thereby changing the conductivity of the variable orifice plate 12.

The synthetic conductivity C _TP of the variable orifice plate 12 from the plurality of orifices 13 is the sum of the conductivity C _n of the orifices 13 , for example, when there are 10 orifices 13 , C _TP = The manner of C ₁ + C ₂ + ... + C ₁₀ is expressed by the sum of the respective conductivities.

Fig. 11 is a flow chart showing a gas analysis method using the gas analysis device 300 according to Embodiment 3. The analysis method of the gas according to the present embodiment will be described along the flowchart of Fig. 11. The same portions as those of the first embodiment are omitted.

Also in the present embodiment, as in the first embodiment, the analysis chamber for measurement and analysis is selected in accordance with the gas amount of the residual gas of the test body 3 measured by the vacuum gauge G0. Although the selection in the analysis chamber is the same as that of the first embodiment in determining the pressure derived from the sample chamber 1 in proportion to the amount of gas of the residual gas, in the present embodiment, a variable orifice plate is added afterwards. The point of operation of the conductivity adjustment of 12 is different from that of the first embodiment, and therefore, the description will be made.

First, when the measured value of the vacuum gauge G0 is less than P ₀ ^* , the gas analyzer 300 is as shown in the flowchart of FIG. 11, and the residual gas is measured and analyzed in the first analysis chamber 6 in the same manner as in the first embodiment. Thereafter, the control calculation device 9 of the third embodiment adjusts the conductivity of the variable orifice plate 12 (step S301). An example of the adjustment method is illustrated using Figure 12.

Fig. 12 is a view showing an example of temporal changes in the pressure of the first analysis chamber 6 before and after opening and closing of the vacuum valve VV1 calculated by the control calculation unit 9 based on the pressure P _{1 of the} sample chamber 1. Fig. 12 shows the pressure P ₁ of the first analysis chamber 6 obtained in each conductivity when the number of openings of the orifice 13 of the variable orifice plate 12 is changed to 1, 3, or 10, respectively. .

In Figure 12 the opening 10 of the number of plotted, after opening the vacuum valve VV1, several seconds of residual gas outgassing, pressure P ₁ is a first analysis chamber 6 reaches the background pressure p1. That is, when the number of openings is 10, it is impossible to obtain a measurement point sufficient for the mass spectrometer MS1 to resolve the partial pressure. On the other hand, the number of openings of the orifices 13 in the variable orifice plate 12 is blocked by the lid 15, and the conductivity becomes small. As shown in the figure, the number of openings 3 and the number of openings 1 can increase the measurement points. .

However, when the conductivity is too small, the inclination of the graph becomes smaller, and it becomes impossible to ignore the release from the inner wall surface of the space (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7). The effect of pressure rise caused by gas. At this time, the accuracy of the analysis in the partial pressure measurement is also reduced. Therefore, the control calculation device 9 adjusts the flow rate of the gas which is released from the first analysis chamber 6 by increasing the conductivity.

When the residual gas is measured and analyzed in the first analysis chamber 6 as described above, the calculation device 9 is controlled so that the outgas from the first analysis chamber 6 does not become too large or too small, corresponding to the pressure of the first analysis chamber 6. Adjustment The conductivity of the variable orifice plate 12. Here, the pressure is adjusted in accordance with the pressure of the first analysis chamber 6, but it is not limited thereto, and the conductivity may be adjusted in accordance with the amount of gas of the residual gas, and the conductivity may be adjusted in accordance with the pressure of the sample chamber 1 and adjusted. There is no limit to the method.

Next, when the measured value of the vacuum gauge G0 is equal to or greater than the threshold value P ₀ ^* , as shown in the flowchart of FIG. 11, the gas analyzing device 300 performs the measurement of the residual gas in the second analysis chamber 7 as in the first embodiment. ,analysis. Thereafter, the control calculation device 9 adjusts the conductivity of the variable orifice plate 12 (step S302). An example of the adjustment method is illustrated using Figure 13.

Fig. 13 is a view showing an example of temporal changes in the pressure of the second analysis chamber 7 before and after opening and closing of the vacuum valve VV1 calculated by the control unit 9 based on the pressure P _{1 of the} sample chamber 1. In Fig. 13, the pressure P in the second analysis chamber 7 of each conductivity obtained when the number of openings of the orifice 13 of the variable orifice plate 12 is changed to 1, 3, and 10, respectively. ₂ .

When the number of openings is 10 in Fig. 13, the pressure of the second analysis chamber 7 immediately after the vacuum valve VV1 is opened exceeds P _qms (= 1.0 × 10 ^-3 Pa), and the residual gas cannot be immediately released. Unable to get enough measurement points.

At this time, the control calculation device 9 blocks the opening of the variable orifice plate 12 by the lid 15, and the conductivity is made small by the number of openings 3 and the number of openings 1. Thereby, the gas analyzing device 300 can suppress the pressure of the second analysis chamber 7 from _reaching P _qms while securing the measurement point.

However, when the conductivity is too small, the amount of gas introduced into the second analysis chamber 7 per unit time is small, and the vacuum valve VV1 is opened. The pressure change of the second analysis chamber 7 before and after closing becomes too small. At this time, the accuracy of the analysis in the partial pressure measurement is also reduced. Therefore, the control calculation device 9 performs adjustment for increasing the conductivity and increasing the gas flow rate of the residual gas in the second analysis chamber 7.

When the residual gas is measured in the second analysis chamber 7 and analyzed, the pressure of the second analysis chamber 7 is controlled, and the calculation device 9 is adjusted so that the outgas from the intermediate chamber 4 does not become too large or too small. The conductivity of the orifice plate 12 is changed. Here, the conductivity is adjusted in accordance with the pressure of the second analysis chamber 7, but it is not limited thereto, and the conductivity may be adjusted in accordance with the amount of gas of the residual gas, and the conductivity may be adjusted in accordance with the pressure of the sample chamber 1 to adjust the conductivity. There is no limit to the way.

Since the conductivity adjustment is the same as that of the first embodiment and the second embodiment, the description thereof is omitted. The effects of the present embodiment will be described below. In the present embodiment, since the variable aperture plate 12 is provided, since the detection sensitivity is adjusted after the analysis chamber is selected, the gas partial pressure measurement with higher accuracy can be performed as compared with the first embodiment and the second embodiment. . In addition, this embodiment demonstrates the part different from Embodiment 1. The other parts are the same as those in the first embodiment.

In the gas analyzer of the present invention, the gas system released from the inner wall surfaces of the respective spaces (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) serves as a background for the vacuum gauge and the mass spectrometer. , has an adverse effect on measurement accuracy.

Therefore, the materials used in each space are desirably constructed of materials that release less gas, and are useful to reduce the gases. The surface area of the inner wall surface can be minimized by the surface treatment by polishing or etching. Further, when vacuuming is performed, each space (the sample chamber 1, the intermediate chamber 4, the first analysis chamber 6, and the second analysis chamber 7) is desirably baked from the outside in advance by a heating device such as a rubber heater. (baking).

Further, the gas analysis device and the gas analysis method of the present invention are designed so as not to deviate from the present invention as long as the movement of the gas molecules in the respective spaces of the gas analysis device and the movement of the gas molecules in the orifice plate is established as a condition for molecular flow operation. It can be implemented in a variety of variations within the scope.

Claims (5)

A gas analysis device comprising: a sample chamber for taking out residual gas from a test body in a vacuum, wherein the intermediate chamber is connected to the residual gas from the sample chamber through a first vacuum valve in a vacuum To the sample chamber; the first analysis chamber is connected to the intermediate chamber through a second vacuum valve in a vacuum to obtain the residual gas from the intermediate chamber; the second analysis chamber is in the vacuum, through the hole a mouth plate connected to the intermediate chamber in such a manner as to obtain the aforementioned residual gas from the intermediate chamber; a vacuum gauge for measuring the amount of the gas of the residual gas in the sample chamber; and an outgas portion for performing the second analysis from the foregoing The chamber releases the residual gas; the control calculation unit closes the second vacuum valve when the gas amount is greater than a threshold value, and when the gas amount does not reach the threshold value, opens the second vacuum valve, and the vacuum gauge measures After the amount of the residual gas, the first vacuum valve is opened; and one or more mass spectrometers are used to When the above value, the analysis is to obtain a second analysis of the residual gas chamber, while gas amount is less than the aforementioned threshold foregoing, the analysis is to obtain the first chamber of the residual gas analysis. The gas analysis device according to claim 1, wherein the mass spectrometer first mass spectrometer is disposed in the first analysis chamber, and when the gas amount does not reach the threshold value, the analysis is obtained as described above. The residual gas in the first analysis chamber and the second mass spectrometer are provided in the second analysis chamber, and when the gas amount is equal to or higher than the threshold value, the residual gas obtained in the second analysis chamber is analyzed. The gas analysis device according to claim 1, wherein the first analysis chamber is connected to the second analysis chamber so as to be capable of acquiring the residual gas through a third vacuum valve, and the control calculation unit is And opening the third vacuum valve when the gas amount is greater than the threshold value, and closing the third vacuum valve when the gas amount does not reach the threshold value, wherein the mass spectrometer is disposed in the first analysis chamber when the gas is When the amount is equal to or higher than the threshold value, the residual gas obtained in the second analysis chamber is analyzed, and when the gas amount does not reach the threshold value, the residual gas obtained in the first analysis chamber is analyzed. The gas analysis device according to any one of claims 1 to 3, wherein the control calculation unit adjusts the orifice plate in accordance with a gas amount of the residual gas. Conductivity. A gas analysis method comprising: a step of taking out a residual gas from a test body in a sample chamber; a step of measuring a gas amount of the residual gas; and when the gas amount of the residual gas does not reach a threshold value, the through-vacuum valve and the sample are a first analysis chamber connected to the intermediate chamber connected to the chamber, in a state in which the vacuum valve is opened, a step of obtaining the residual gas from the sample chamber to the first analysis chamber; and when the gas amount of the residual gas is the threshold value In the above, the step of closing the vacuum valve and the step of obtaining the residual gas from the sample chamber to the second analysis chamber through the orifice plate in the second analysis chamber through which the perforated orifice plate is connected to the intermediate chamber And a step of analyzing the residual gas to be obtained by the first analysis chamber and the second analysis chamber described above by a mass spectrometer.