Absorption system for silane gas metal impurity analysis

Abstract

The utility model discloses an absorption system for silane gas metal impurity analysis. The absorption system comprises an impurity analysis pipeline, a sample tail gas emptying pipeline, a sample gas absorption device, a blank sample analysis pipeline, a purging tail gas emptying pipeline, a blank sample absorption device, a sample injection pipeline, a first purging gas inlet pipeline and a second purging gas inlet pipeline, the sample gas absorption device is connected with the gas outlet end of the impurity analysis pipeline and the gas inlet end of the sample tail gas emptying pipeline; the blank sample absorption device is connected with the gas outlet end of the blank sample analysis pipeline and the gas inlet end of the purging tail gas emptying pipeline; the gas outlet end of the sample injection pipeline and the gas outlet end of the first purge gas inlet pipeline are connected in parallel to the gas inlet end of the impurity analysis pipeline; and the gas outlet end of the second purge gas inlet pipeline is connected to the gas inlet end of the blank sample analysis pipeline. According to the utility model, a sample for silane gas metal impurity analysis and a blank control sample can be simultaneously obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of silane gas trace analysis, in particular to an absorption system for silane gas metal impurity analysis. Background Art

[0002] Silane gas is an indispensable raw material gas in the semiconductor and solar cell material industries and is widely used in the electronics industry. Silane is used in the industry to make silicon thin films, which can stabilize silicon thin films during processing. This stability enables silicon thin films to be used in many application fields, such as microprocessors, flat-panel TVs, etc. However, with the development of science and technology, the requirements for various indicators in the semiconductor field are gradually increasing, especially the control of metal impurities. Because even a small amount of metal impurities can have a great impact on the quality of products prepared with the silane. Therefore, it is of great significance to accurately detect trace metal impurities in silane.

[0003] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the utility model, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in this field. Utility Model Content

[0004] Purpose of the utility model: The technical problem to be solved by the utility model is to provide an absorption system for metal impurity analysis of silane gas in view of the deficiencies in the prior art, which can simultaneously obtain samples for metal impurity analysis of silane gas and blank control samples.

[0005] In order to solve the above technical problems, the utility model discloses an absorption system for analyzing metal impurities in silane gas, which comprises an impurity analysis pipeline, a sample tail gas venting pipeline, a sample gas absorption device, a blank sample analysis pipeline, a purge tail gas venting pipeline, a blank sample absorption device, a sampling pipeline, a first purge gas inlet pipeline and a second purge gas inlet pipeline; the sample gas absorption device is connected to the gas outlet end of the impurity analysis pipeline and the gas inlet end of the sample tail gas venting pipeline; the blank sample absorption device is connected to the gas outlet end of the blank sample analysis pipeline and the gas inlet end of the purge tail gas venting pipeline; the gas outlet end of the sampling pipeline and the gas outlet end of the first purge gas inlet pipeline are connected in parallel to the gas inlet end of the impurity analysis pipeline; the gas outlet end of the second purge gas inlet pipeline is connected to the gas inlet end of the blank sample analysis pipeline.

[0006] Specifically, the sampling pipeline includes a main sampling pipeline and one or more branch sampling pipelines, the outlet ends of the one or more branch sampling pipelines are connected in parallel to the inlet end of the main sampling pipeline; each branch sampling pipeline is respectively provided with a control valve for controlling the on-off of the branch sampling pipeline in which it is located.

[0007] Furthermore, it also includes a replacement pipeline and a sample gas replacement valve arranged on the replacement pipeline, and the air inlet end of the replacement pipeline is connected to the air outlet end of the sample injection line and the air inlet end of the impurity analysis line.

[0008] Specifically, the sampling pipeline comprises a sample gas pressure reducing valve and a sample valve switch, both of which are arranged on the sampling main pipeline, and the sample valve switch is located downstream of the sample gas pressure reducing valve.

[0009] Specifically, the first purge gas intake pipeline includes a first purge gas intake pipeline, a first purge gas isolation valve and a sample gas pressure maintaining pressure gauge; the first purge gas isolation valve is arranged on the first purge gas intake pipeline, and is used to control the on-off of the first purge gas intake pipeline; the sample gas pressure maintaining pressure gauge is connected to the first purge gas intake pipeline, and is used to measure the internal air pressure of the first purge gas intake pipeline.

[0010] Specifically, the second purge gas intake pipeline includes a second purge gas intake pipeline, a second purge gas isolation valve and a purge gas pressure reducing valve. The second purge gas isolation valve and the purge gas pressure reducing valve are arranged on the second purge gas intake pipeline, and the purge gas pressure reducing valve is located downstream of the second purge gas isolation valve.

[0011] Specifically, the impurity analysis pipeline includes an impurity analysis pipeline, a sample gas flow regulating valve and a second flow meter. The sample gas flow regulating valve and the second flow meter are both arranged on the impurity analysis pipeline, and the second flow meter is located downstream of the sample gas flow regulating valve.

[0012] Specifically, the blank sample analysis pipeline includes a blank sample analysis pipeline, a purge gas flow regulating valve and a first flow meter. The purge gas flow regulating valve and the first flow meter are both arranged on the blank sample analysis pipeline and the first flow meter is located downstream of the purge gas flow regulating valve.

[0013] Specifically, the sample exhaust gas vent line includes a sample exhaust gas vent pipeline and a sample exhaust gas valve arranged on the sample exhaust gas vent pipeline, and the sample exhaust gas valve is used to control the on-off of the sample exhaust gas vent pipeline; the purge exhaust gas vent line includes a purge exhaust gas vent pipeline and a purge exhaust gas valve arranged on the purge exhaust gas vent pipeline, and the purge exhaust gas valve is used to control the on-off of the purge exhaust gas vent pipeline.

[0014] Specifically, it also includes a purge gas main line, the air inlet end of the first purge gas inlet line and the air inlet end of the second purge gas inlet line are connected in parallel to the air outlet end of the purge gas main line, and the purge gas main line is used to introduce purge gas.

[0015] Beneficial effects:

[0016] (1) The utility model can simultaneously obtain samples for silane gas metal impurity analysis and blank control samples. Through detection, it is possible to timely discover whether production is abnormal, providing effective data support for the overall production process.

[0017] (2) An embodiment of the present invention provides a plurality of switchable sampling branches for sampling, allowing the user to use one system to monitor metal trace impurities in multiple silane gas production systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0019] Figure 1 A system block diagram of an absorption system for analyzing metal impurities in silane gas disclosed in one embodiment of the utility model.

[0020] Description of the accompanying drawings:

[0021] 101, purge gas pressure reducing valve; 102, sample gas pressure reducing valve; 201, sample gas pressure maintaining pressure gauge; 202, purge gas pressure reducing valve outlet pressure gauge; 203, purge gas pressure reducing valve inlet pressure gauge; 204, sample gas pressure reducing valve outlet pressure gauge; 205, sample gas pressure reducing valve inlet pressure gauge; 301, sample gas inlet connector; 302, sample tail gas outlet connector; 303, purge gas inlet connector; 304, purge gas outlet connector; 401, first flow meter; 402, second flow meter; 501, first purge gas isolation valve; 502, second purge gas isolation valve; 506, sample gas replacement valve; 507, purge gas flow regulating valve; 508, sample gas flow regulating valve; 509, sample valve switch; 510, purge tail gas valve; 511, sample tail gas valve. DETAILED DESCRIPTION

[0022] Because even a small amount of metal impurities can have a significant impact on the quality of the products prepared using the silane, it is of great significance to accurately detect trace amounts of metal impurities in silane.

[0023] This embodiment discloses an absorption system for analyzing metal impurities in silane gas, see Figure 1The absorption system includes an impurity analysis pipeline, a sample tail gas venting pipeline, a sample gas absorption device 601, a blank sample analysis pipeline, a purge tail gas venting pipeline, a blank sample absorption device 602, a sample injection pipeline, a first purge gas inlet pipeline, and a second purge gas inlet pipeline. The sample gas absorption device 601 is connected to the gas outlet end of the impurity analysis pipeline and the gas inlet end of the sample tail gas venting pipeline. The blank sample absorption device 602 is connected to the gas outlet end of the blank sample analysis pipeline and the gas inlet end of the purge tail gas venting pipeline. The gas outlet end of the sample injection pipeline and the gas outlet end of the first purge gas inlet pipeline are connected in parallel to the gas inlet end of the impurity analysis pipeline. The gas outlet end of the second purge gas inlet pipeline is connected to the gas inlet end of the blank sample analysis pipeline.

[0024] In this embodiment, the sample gas to be analyzed is silane gas containing metal trace impurities, and the purge gas is nitrogen. The inlet end of the first purge gas inlet pipeline and the inlet end of the second purge gas inlet pipeline can be connected to an external purge gas supply source respectively.

[0025] After the sample gas absorption device 601 and the blank sample absorption device 602 in this embodiment are removed, ICP-MS can be used to analyze the metal impurities in the absorption liquid in each absorption device to detect the metal impurity content in the silane gas.

[0026] The sample gas absorption device 601 and the blank sample absorption device 602 can adopt the same structure. Taking the sample gas absorption device 601 as an example, the sample gas absorption device 601 includes a first absorption bottle and a second absorption bottle sealed and connected to the first absorption bottle, the first absorption bottle is provided with an inlet connector, and the second absorption bottle is provided with an outlet connector.

[0027] More specifically, see Figure 1 The sample gas absorption device 601 is connected to the outlet end of the impurity analysis pipeline through the sample gas inlet connector 301, and the sample gas absorption device 601 is connected to the inlet end of the sample tail gas venting pipeline through the sample tail gas outlet connector 302. The blank sample absorption device 602 is connected to the outlet end of the blank sample analysis pipeline through the purge gas inlet connector 303. The blank sample absorption device 602 is connected to the inlet end of the purge tail gas venting pipeline through the purge gas outlet connector 304.

[0028] Specifically, see Figure 1 The sampling pipeline includes a main sampling line 7051 and one or more branch sampling lines 7052, and the outlet ends of the one or more branch sampling lines 7052 are connected in parallel to the inlet end of the main sampling line 7051. Each branch sampling line 7052 is provided with a control valve 503 for controlling the on-off of the branch sampling line 7052 where it is located.

[0029] This embodiment provides a plurality of mutually switchable sampling branch pipelines for sampling, allowing the user to use one system to monitor metal trace impurities in multiple silane gas production systems.

[0030] Specifically, see Figure 1 , the injection line includes a sample gas pressure reducing valve 102 and a sample valve switch 509, both of which are arranged on the injection main line 7051 and the sample valve switch 509 is located downstream of the sample gas pressure reducing valve 102. More specifically, the injection line includes a sample gas pressure reducing valve inlet pressure gauge 205 and a sample gas pressure reducing valve outlet pressure gauge 204, the sample gas pressure reducing valve inlet pressure gauge 205 is connected to the inlet of the sample gas pressure reducing valve 102, and the sample gas pressure reducing valve outlet pressure gauge 204 is connected to the outlet of the sample gas pressure reducing valve 102. The sample gas pressure reducing valve inlet pressure gauge 205 and the sample gas pressure reducing valve outlet pressure gauge 204 are used to respectively display the gas pressure of the injection main line 7051 before and after decompression.

[0031] Specifically, see Figure 1 The first purge gas inlet pipeline includes a first purge gas inlet pipeline 703, a first purge gas isolation valve 501 and a sample gas pressure maintaining pressure gauge 201. The first purge gas isolation valve 501 is arranged on the first purge gas inlet pipeline 703, and is used to control the on-off of the first purge gas inlet pipeline 703. The sample gas pressure maintaining pressure gauge 201 is connected to the first purge gas inlet pipeline 703, and is used to measure the internal air pressure of the first purge gas inlet pipeline 703.

[0032] Specifically, see Figure 1 The second purge gas inlet pipeline includes a second purge gas inlet pipeline 704, a second purge gas isolation valve 502 and a purge gas pressure reducing valve 101. The second purge gas isolation valve 502 and the purge gas pressure reducing valve 101 are arranged on the second purge gas inlet pipeline 704, and the purge gas pressure reducing valve 101 is located downstream of the second purge gas isolation valve 502. More specifically, the second purge gas inlet pipeline includes a purge gas pressure reducing valve inlet pressure gauge 203 and a purge gas pressure reducing valve outlet pressure gauge 202. The purge gas pressure reducing valve inlet pressure gauge 203 is connected to the inlet of the purge gas pressure reducing valve 101, and the purge gas pressure reducing valve outlet pressure gauge 202 is connected to the outlet of the purge gas pressure reducing valve 101. The purge gas pressure reducing valve inlet pressure gauge 203 and the purge gas pressure reducing valve outlet pressure gauge 202 are used to respectively display the gas pressure of the second purge gas inlet pipeline 704 before and after pressure reduction.

[0033] Specifically, see Figure 1 The impurity analysis pipeline includes an impurity analysis pipeline 705, a sample gas flow regulating valve 508 and a second flow meter 402. The sample gas flow regulating valve 508 and the second flow meter 402 are both arranged on the impurity analysis pipeline 705, and the second flow meter 402 is located downstream of the sample gas flow regulating valve 508.

[0034] Specifically, see Figure 1 The blank sample analysis pipeline includes a blank sample analysis pipeline 706, a purge gas flow regulating valve 507 and a first flow meter 401. The purge gas flow regulating valve 507 and the first flow meter 401 are both arranged on the blank sample analysis pipeline 706 and the first flow meter 401 is located downstream of the purge gas flow regulating valve 507.

[0035] Specifically, see Figure 1 The sample tail gas venting pipeline includes a sample tail gas venting pipeline 707 and a sample tail gas valve 511 disposed on the sample tail gas venting pipeline 707, and the sample tail gas valve 511 is used to control the on-off of the sample tail gas venting pipeline 707. The purge tail gas venting pipeline includes a purge tail gas venting pipeline 708 and a purge tail gas valve 510 disposed on the purge tail gas venting pipeline 708, and the purge tail gas valve 510 is used to control the on-off of the purge tail gas venting pipeline 708.

[0036] For a system in which the main injection line 7051 is too long, in order to obtain more accurate measurements, the absorption system disclosed in this embodiment may further include a replacement line 702 and a sample gas replacement valve 506 disposed on the replacement line 702, and the air inlet end of the replacement line 702 is connected to the air outlet end of the injection line and the air inlet end of the impurity analysis line.

[0037] In this embodiment, by providing a replacement pipeline 702, the previous sample gas existing in the sampling pipeline is replaced into the replacement pipeline before sampling, thereby preventing the previous sample gas from interfering with the analysis of the current sample gas.

[0038] In order to reduce the demand for the number of external purge gas supply sources, the absorption system disclosed in this embodiment may also include a purge gas main line 709, and the inlet end of the first purge gas inlet line 703 and the inlet end of the second purge gas inlet line 704 are connected in parallel to the outlet end of the purge gas main line 709, and the purge gas main line 709 is used to introduce the purge gas.

[0039] In this embodiment, the air inlet end of the first purge gas inlet pipeline 703 and the air inlet end of the second purge gas inlet pipeline 704 are connected in parallel to the air outlet end of the purge gas main pipeline 709. The air inlet end of the purge gas main pipeline 709 only needs to be connected to an external purge gas supply source to realize the purge gas supply of the absorption system, thereby saving costs.

[0040] Below, refer to Figure 1 , the use process of the absorption system of this embodiment is explained.

[0041] The sample gas to be analyzed passes through the sampling branch line 7052 corresponding to the control valve 503, and enters the sample gas absorption device 601 through the second flowmeter 402. The sample tail gas is discharged through the sample tail gas vent line 707 where the sample tail gas valve 511 is located. After the absorption is completed, the sample gas absorption device 601 is removed, and the absorption liquid in the sample gas absorption device 601 is analyzed for metal impurities using an ICP-MS inductively coupled plasma mass spectrometer to detect the metal trace impurity content contained in the silane gas. The specific steps are as follows:

[0042] Step 1: Maintain pressure

[0043] First, ensure that all valves 501 - 511 are in a closed state. Connect the sample gas inlet connector 301 and the sample tail gas outlet connector 302 of the sample gas absorption device 601 , and the purge gas inlet connector 303 and the purge gas outlet connector 304 of the blank sample absorption device 602 .

[0044] The pressure of the nitrogen main valve is about X MPa when it is opened. Open the second isolation valve 502 of the purge gas, and adjust the purge gas pressure reducing valve 101 to an outlet pressure of X MPa. Slowly open the purge gas flow regulating valve 507. After it is opened, there are bubbles in the blank sample absorption device 602, such as the blank absorption bottle, and the value of the second flow meter 402 continues to decrease. Since the purge tail gas valve 510 is not opened, the first flow meter 401 does not display the flow. Close the second isolation valve 502 of the purge gas, and record the value of the outlet pressure gauge 202 of the purge gas pressure reducing valve 101.

[0045] Open the first purge gas isolation valve 501, the sample gas pressure gauge 201 displays a value of about X MPa, slowly open the sample gas flow regulating valve 508, the sample gas absorption device 601, for example, absorbs bubbles in the sample bottle, the value of the first flow meter 401 continues to decrease, at this time the sample tail gas valve 511 is not opened, and the second flow meter 402 does not display the flow. Close the first purge gas isolation valve 501, and record the value of the sample gas pressure gauge 201.

[0046] After maintaining the pressure for a certain period of time, if the values ​​of the outlet pressure gauge 202 of the purge gas pressure reducing valve 101 and the sample gas pressure maintaining pressure gauge 201 do not change, it means that the pressure maintenance is successful. If the values ​​decrease, each interface needs to be tightened and the pressure must be maintained again.

[0047] Step 2: Purge

[0048] Open the second purge gas isolation valve 502 and the purge tail gas valve 510, adjust the purge gas pressure reducing valve 101 to an outlet pressure of Y MPa, and adjust the purge gas flow regulating valve 507 until the first flow meter 401 displays Z ml / min. Open the first purge gas isolation valve 501 and the sample tail gas valve 511, and adjust the sample gas flow regulating valve 508 until the second flow meter 402 displays Z ml / min.

[0049] After a certain period of purging, close the first purge gas isolation valve 501 and the sample gas flow regulating valve 508, confirm that the sample gas pressure reducing valve 102 is in a closed state, and close the second purge gas isolation valve 502 and the purge tail gas valve 510.

[0050] Step 3: Sampling

[0051] Open one of the multiple control valves 503. Adjust the sample gas pressure reducing valve 102 until the outlet pressure gauge is Y MPa, open the sample valve switch 509, open the sample gas replacement valve 506, and the sample gas starts to replace the replacement pipeline. After a certain period of time, close the sample gas replacement valve 506. Slowly adjust the sample gas flow regulating valve 508 so that the second flow meter 402 displays Zml / min, and the outlet pressure of the sample gas pressure reducing valve 102 is Y MPa.

[0052] After a period of time, the absorption system is finished. The external sample gas main valve is closed on site and the pressure is released to YMPa. During the pressure release process, the sample gas flow regulating valve 508 is adjusted at any time until the second flow meter 402 displays Z ml / min.

[0053] Step 4: Secondary purge

[0054] Since silane gas will explode when it meets air, for operational safety, before the sample gas absorption device 601 and the blank sample absorption device 602 are removed from the absorption system, it is necessary to use purge gas to purge each pipeline twice to clear the silane gas.

[0055] After the absorption is completed, close the corresponding sample gas main valve and the corresponding control valve 503. Open the first purge gas isolation valve 501, adjust the sample gas flow control valve 508 until the flow meter displays Z ml / min, and close the first purge gas isolation valve 501 after a certain period of purging. After the second flow meter 402 displays zero, close the sample tail gas valve 511.

[0056] Open the second purge gas isolation valve 502 and the purge tail gas valve 510, adjust the outlet pressure of the purge gas pressure reducing valve 101 to Y MPa, adjust the purge gas flow regulating valve 507 until the first flow meter 401 displays Z ml / min, and close the second purge gas isolation valve 502 and the purge tail gas valve 510 after purging for a certain period of time.

[0057] Slowly remove the purge gas outlet connector 304 and the purge gas inlet connector 303 in sequence, connect the purge pipeline, and seal the interface of the blank sample absorption device 602 with a sealing film.

[0058] Slowly remove the sample tail gas outlet connector 302 and the sample gas inlet connector 301 in sequence, connect the purge pipeline, and seal the interface of the sample gas absorption device 601 with a sealing film.

[0059] After installing the protection bottle, open the first isolation valve 501 of the purge gas, the second isolation valve 502 of the purge gas, the purge tail gas valve 510 and the sample tail gas valve 511. After purging for a certain period of time, close the first isolation valve 501 of the purge gas, the second isolation valve 502 of the purge gas, the purge gas flow regulating valve 507, the sample gas flow regulating valve 508, the purge tail gas valve 510 and the sample tail gas valve 511. The protection bottle can adopt the same structure as the blank sample absorption device to keep the gas path of the system airtight.

[0060] The utility model provides a concept and method for an absorption system for analyzing metal impurities in silane gas. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. An absorption system for analyzing metal impurities in silane gas, characterized in that: It comprises an impurity analysis pipeline, a sample tail gas venting pipeline, a sample gas absorption device (601), a blank sample analysis pipeline, a purge tail gas venting pipeline, a blank sample absorption device (602), a sample injection pipeline, a first purge gas inlet pipeline and a second purge gas inlet pipeline; the sample gas absorption device (601) is connected to the outlet end of the impurity analysis pipeline and the inlet end of the sample tail gas venting pipeline; The blank sample absorption device (602) is connected to the outlet end of the blank sample analysis pipeline and the inlet end of the purge tail gas venting pipeline; the outlet end of the injection pipeline and the outlet end of the first purge gas inlet pipeline are connected in parallel to the inlet end of the impurity analysis pipeline; the outlet end of the second purge gas inlet pipeline is connected to the inlet end of the blank sample analysis pipeline.

2. The absorption system for analyzing metal impurities in silane gas according to claim 1, characterized in that: The sampling pipeline comprises a main sampling pipeline (7051) and one or more branch sampling pipelines (7052), wherein the outlet ends of the one or more branch sampling pipelines (7052) are connected in parallel to the inlet end of the main sampling pipeline (7051); each branch sampling pipeline (7052) is provided with a control valve (503) for controlling the on-off of the branch sampling pipeline (7052) in which it is located.

3. The absorption system for analyzing metal impurities in silane gas according to claim 2, characterized in that: It also includes a replacement pipeline (702) and a sample gas replacement valve (506) arranged on the replacement pipeline (702), and the air inlet end of the replacement pipeline (702) is connected to the air outlet end of the sample injection line and the air inlet end of the impurity analysis line.

4. An absorption system for analyzing metal impurities in silane gas according to any one of claims 2 to 3, characterized in that: The injection pipeline comprises a sample gas pressure reducing valve (102) and a sample valve switch (509), wherein the sample gas pressure reducing valve (102) and the sample valve switch (509) are both arranged on the injection main line (7051), and the sample valve switch (509) is located downstream of the sample gas pressure reducing valve (102).

5. The absorption system for analyzing metal impurities in silane gas according to claim 4, characterized in that: The first purge gas inlet pipeline comprises a first purge gas inlet pipeline (703), a first purge gas isolation valve (501) and a sample gas pressure maintaining pressure gauge (201); the first purge gas isolation valve (501) is arranged on the first purge gas inlet pipeline (703) and is used to control the on-off of the first purge gas inlet pipeline (703); the sample gas pressure maintaining pressure gauge (201) is connected to the first purge gas inlet pipeline (703) and is used to measure the internal air pressure of the first purge gas inlet pipeline (703).

6. The absorption system for analyzing metal impurities in silane gas according to claim 5, characterized in that: The second purge gas inlet pipeline comprises a second purge gas inlet pipeline (704), a second purge gas isolation valve (502) and a purge gas pressure reducing valve (101). The second purge gas isolation valve (502) and the purge gas pressure reducing valve (101) are arranged on the second purge gas inlet pipeline (704), and the purge gas pressure reducing valve (101) is located downstream of the second purge gas isolation valve (502).

7. The absorption system for analyzing metal impurities in silane gas according to claim 6, characterized in that: The impurity analysis pipeline comprises an impurity analysis pipeline (705), a sample gas flow regulating valve (508) and a second flow meter (402); the sample gas flow regulating valve (508) and the second flow meter (402) are both arranged on the impurity analysis pipeline (705), and the second flow meter (402) is located downstream of the sample gas flow regulating valve (508).

8. The absorption system for analyzing metal impurities in silane gas according to claim 7, characterized in that: The blank sample analysis pipeline comprises a blank sample analysis pipeline (706), a purge gas flow regulating valve (507) and a first flow meter (401), wherein the purge gas flow regulating valve (507) and the first flow meter (401) are both arranged on the blank sample analysis pipeline (706) and the first flow meter (401) is located downstream of the purge gas flow regulating valve (507).

9. The absorption system for analyzing metal impurities in silane gas according to claim 8, characterized in that: The sample tail gas venting pipeline comprises a sample tail gas venting pipeline (707) and a sample tail gas valve (511) arranged on the sample tail gas venting pipeline (707), and the sample tail gas valve (511) is used to control the on-off of the sample tail gas venting pipeline (707); the purge tail gas venting pipeline comprises a purge tail gas venting pipeline (708) and a purge tail gas valve (510) arranged on the purge tail gas venting pipeline (708), and the purge tail gas valve (510) is used to control the on-off of the purge tail gas venting pipeline (708).

10. The absorption system for analyzing metal impurities in silane gas according to claim 9, characterized in that: It also includes a purge gas main line (709), wherein the air inlet end of the first purge gas inlet line (703) and the air inlet end of the second purge gas inlet line (704) are connected in parallel to the air outlet end of the purge gas main line (709), and the purge gas main line (709) is used to introduce the purge gas.

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