Low-temperature sample introduction system for diborane sample gas

Abstract

The utility model provides a low-temperature sample introduction system for diborane sample gas. The low-temperature sample introduction system comprises a sample introduction pipeline, a carrier gas pipeline, a cooling unit and a switching valve assembly, the sample introduction pipeline and the carrier gas pipeline are respectively connected to the switching valve assembly; wherein the switching valve assembly comprises a quantitative loop and a six-way valve connected with the quantitative loop, the quantitative loop is communicated with the sample introduction pipeline, and the six-way valve is communicated with the carrier gas pipeline; the cooling unit comprises a cooling fan and a pipeline cooling device arranged on the sample feeding pipeline and the carrier gas pipeline; a diborane sample air valve, a purging valve and a vacuumizing valve are arranged on the sample feeding pipeline. The low-temperature sampling system disclosed by the utility model is used for carrying out low-temperature pretreatment on diborane sample gas, so that the decomposition of diborane is effectively inhibited, and the sampling accuracy of the diborane sample gas is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of diborane sampling, in particular to a low-temperature sampling system for diborane sample gas. Background Art

[0002] Electronic special gases are widely used in high-tech industries such as semiconductors and microelectronics. Since semiconductor and microelectronics technologies are developing towards high performance and high integration, the purity requirements for electronic special gases are getting higher and higher, and at the same time, higher requirements are imposed on the analysis techniques and methods related to electronic special gases.

[0003] As a kind of electronic special gas, the accurate analysis and detection of diborane are of great significance for the research and development and production of diborane gas. However, due to the extremely unstable nature of diborane, it has the characteristics of being easily decomposed into higher-order boranes at room temperature and being extremely reactive with water and oxygen in the air. Therefore, when detecting diborane, in order to ensure that diborane enters the detector completely, it is necessary to perform low-temperature sampling treatment on it, which is of great significance for the quantitative analysis and impurity detection of diborane.

[0004] Most of the existing sampling technologies perform sampling at room temperature or even at higher temperatures, which will cause partial decomposition of diborane and is not conducive to quantitative analysis and impurity detection. Summary of the Utility Model

[0005] In order to overcome the above-mentioned technical problems, the utility model provides a low-temperature sampling system for diborane sample gas, which performs low-temperature pretreatment on diborane before it enters the chromatograph, effectively inhibiting the decomposition of diborane itself, thereby ensuring the accuracy of the measurement results.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] The utility model provides a low-temperature sampling system for diborane sample gas, the low-temperature sampling system includes a sampling pipeline, a carrier gas pipeline, a cooling unit and a switching valve assembly; the sampling pipeline and the carrier gas pipeline are respectively connected to the switching valve assembly;

[0008] Wherein, the switching valve assembly includes a quantitative loop and a six-way valve connected to the quantitative loop, the quantitative loop is communicated with the sampling pipeline, and the six-way valve is communicated with the carrier gas pipeline;

[0009] The cooling unit includes a cooling fan and a pipeline cooling device arranged on the sampling pipeline and the carrier gas pipeline;

[0010] A diborane sample gas valve, a purge valve and a vacuum pumping valve are arranged on the sampling pipeline.

[0011] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the low-temperature sampling system further includes temperature and pressure measurement units respectively arranged on the sampling pipeline and the carrier gas pipeline;

[0012] The temperature and pressure measurement unit includes a pressure gauge and a thermometer.

[0013] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the pipeline cooling device is composed of a cooling device arranged inside the pipeline and a cycle refrigerating apparatus for providing a cooling medium for the cooling device.

[0014] In the low-temperature sampling system for diborane sample gas provided by the present utility model, a cooling medium inlet and a cooling medium outlet are arranged on the cooling device, and the cycle refrigerating apparatus is connected between the cooling medium inlet and the cooling medium outlet through a pipeline.

[0015] In the low-temperature sampling system for diborane sample gas provided by the present utility model, a carrier gas valve is arranged at the connection between the carrier gas pipeline and the six-way valve.

[0016] In the low-temperature sampling system for diborane sample gas provided by the present utility model, a sampling valve is arranged at the connection between the sampling pipeline and the quantitative loop.

[0017] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the purge valve is connected to a purge gas.

[0018] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the cooling fan is arranged on the top of the six-way valve in the switching valve assembly.

[0019] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the vacuum pump valve is connected to a vacuum pump.

[0020] In the low-temperature sampling system for diborane sample gas provided by the present utility model, the diborane sample gas valve is connected to a diborane sample gas cylinder.

[0021] Adopting the above technical solution, the following technical effects are achieved:

[0022] The low-temperature sampling system provided by the present utility model realizes that the diborane sample gas is always in a low-temperature state during the sampling process through the pipeline cooling device arranged on the sampling pipeline and the carrier gas pipeline and the cooling fan above the six-way valve, effectively inhibits the self-decomposition of diborane, and thus improves the effectiveness and accuracy of the detection of the components and the content of each component in the diborane sample gas.

[0023] The low-temperature sampling system provided by the present utility model has the advantages of simple operation, safety and reliability, compact structure, labor saving, and accurate detection. Description of the Drawings

[0024] Figure 1 It is an embodiment of the low-temperature sampling system for diborane sample gas provided by the present utility model;

[0025] Wherein, 1. purge valve, 2. vacuum pump valve, 3. diborane sample gas valve, 4. sampling valve, 5. carrier gas valve, 6. cooling fan, 7. switching valve assembly, 8. sampling pipeline, 9. carrier gas pipeline, 10. pressure gauge, 11. thermometer, 12. cooling device, 13. circulating refrigerator. Detailed Embodiment

[0026] In order to better understand the present utility model, the following describes it in combination with the specific embodiments of the present utility model.

[0027] A low-temperature sampling system for diborane sample gas provided by the present utility model, as Figure 1 shown, the low-temperature sampling system includes a sampling pipeline 8, a carrier gas pipeline 9, a cooling unit, and a switching valve assembly 7. The sampling pipeline 8 and the carrier gas pipeline 9 are both connected to the switching valve assembly 10 to use the carrier gas transported in the carrier gas pipeline 9 to blow the diborane sample gas in the sampling pipeline 8 into the reaction system.

[0028] In the low-temperature sampling system provided by the present utility model, the switching valve assembly 7 includes a quantitative loop and a six-way valve connected to the quantitative loop. The quantitative loop is communicated with the sampling pipeline 8, and the six-way valve is communicated with the carrier gas pipeline 9. As is well known to those skilled in the art, the function of the quantitative loop is to accurately control the sampling volume into the reaction system, making the sampling data more reliable; the six-way valve is used to control the sample gas and the carrier gas to enter the reaction system. When the valve is closed, the carrier gas and the sample gas flow separately. At this time, the sample gas is filled into the quantitative loop. After the valve is rotated, the carrier gas pushes the sample gas in the quantitative loop into the reaction system. The specific structures of the six-way valve and the quantitative loop mentioned in the present utility model belong to the well-known structures in the art and will not be elaborated here.

[0029] In the low-temperature sampling system provided by the present utility model, the cooling unit includes a pipeline cooling device arranged on the sampling pipeline 8 and the carrier gas pipeline 9 and a cooling fan 6 arranged on the top of the six-way valve. In some specific embodiments, the cooling fan 6 is arranged on the top of the six-way valve for pre-cooling the six-way valve before sampling and keeping the six-way valve in a lower temperature state during continuous sampling. For example, the six-way valve is below 25°C under the condition that no gas passes through.

[0030] In the low-temperature sampling system provided by the present utility model, a diborane sample gas valve 3, a purge valve 1, and a vacuum pumping valve 2 are arranged on the sampling pipeline 8; specifically, one end of the purge valve 1 is connected to the sampling pipeline 8, and the other end is connected to a purge gas to purge and displace the gas existing in the sampling pipeline 8, and the purge gas is switched on and off through the purge valve 1; the purge gas is selected from high-purity helium and high-purity hydrogen. One end of the vacuum pumping valve 2 is connected to the sampling pipeline 8, and the other end is connected to a vacuum device (such as a vacuum pump) to evacuate the gas existing in the sampling pipeline 8. In some specific embodiments, the vacuum degree in the sampling pipeline is controlled at 10 -5 Pa or less, and this is repeated 3 to 5 times.

[0031] In some specific embodiments, the low-temperature sampling system provided by the present utility model further includes temperature and pressure measurement units respectively arranged on the sampling pipeline 8 and the carrier gas pipeline 9; the temperature and pressure measurement unit includes a pressure gauge 10 and a thermometer 11 to measure the temperature of the carrier gas after cooling and the pressure condition of the gas in the pipeline.

[0032] In the low-temperature sampling system provided by the present utility model, the pipeline cooling device is composed of a cooling device 12 arranged in the pipeline and a circulating refrigeration instrument 13 that provides a cooling medium for the cooling device 12. The cooling medium enters the circulating refrigeration instrument 13 in a form of flowing in from the bottom and out from the top to improve the cooling efficiency. The cooling device 12 cools the carrier gas and the sample gas to ensure that the diborane sample gas is in a low-temperature state during the sampling process. In some specific embodiments, the circulating refrigeration instrument 13 is internally provided with a refrigeration device and a pump body to ensure that the cooling medium can circulate and achieve the effect of controlling the temperature of the pipeline.

[0033] In some specific embodiments, the cooling medium in the circulating refrigeration instrument is selected from nitrates with a concentration of 0.3 mol / L to 1.2 mol / L, and the nitrates include but are not limited to sodium nitrate, potassium nitrate, etc. More specifically, the cooling medium selected in the circulating refrigeration instrument 13 on the sampling pipeline 8 is a 0.5 mol / L potassium nitrate solution, and the temperature is controlled at 10 to 25 °C. At this temperature, the self-decomposition of the diborane sample gas can be inhibited, and at the same time, it can ensure that the components in the diborane sample gas do not liquefy. The circulating refrigeration instrument 13 can control the temperature of the cooling medium and achieve long-term continuous refrigeration.

[0034] In some specific embodiments, a carrier gas valve 5 is arranged at the connection between the carrier gas pipeline 9 and the six-way valve to control the on-off of the carrier gas introduced into the switching valve assembly 7.

[0035] In some specific embodiments, a sampling valve 4 is arranged at the connection between the sampling pipeline 8 and the quantitative loop to make the sampling pipeline 8 and the quantitative loop in a connected state or the sampling pipeline 8 and the quantitative loop in a closed state.

[0036] In some specific embodiments, the diborane sample gas valve 3 is connected to a diborane sample gas cylinder to provide sample gas for the reaction system.

[0037] Using the low-temperature sampling system for diborane sample gas provided by the present utility model, the specific operation process is as follows (all valves are in the closed state initially):

[0038] First step, open the purge valve 1, and use high-purity helium or high-purity hydrogen to purge and replace the sampling pipeline 8. After removing the residual gas in the pipeline, close the purge valve 1;

[0039] Second step, open the vacuum valve 2, and perform a vacuum treatment on the sampling pipeline 8 until the pressure reaches below 10 -5 Pa. After the vacuuming is completed, close the vacuum valve 2, and repeat the first step and the second step 3 to 5 times;

[0040] Third step, open the cooling device 12 and the circulating refrigeration instrument 13 on the sampling pipeline 8 and the carrier gas pipeline 9 respectively, and adjust the temperature of the cooling medium to below 20°C;

[0041] Fourth step, open the cooling fan 6 on the top of the six-way valve to pre-cool the six-way valve;

[0042] Fifth step, keep the carrier gas valve 5 always open, adjust the reading of the thermometer 11 on the carrier gas pipeline 9 to below 20°C, and the reading of the pressure gauge 10 is 0.5 - 0.8 MPa;

[0043] Sixth step, open the diborane sample gas cylinder and the diborane sample gas valve 3. After the reading of the thermometer 11 on the sampling pipeline 8 reaches below 20°C and the reading of the pressure gauge 10 is 0.08 - 0.13 MPa, open the sampling valve 4, and purge the quantitative loop for 1 - 2 minutes to complete the cooling and sampling of the diborane sample gas;

[0044] Seventh step, open the six-way valve, and the carrier gas pushes the diborane sample gas into the analytical instrument to analyze its composition and content.

Claims

1. A cryogenic injection system for diborane sample gas, characterized in that, The low-temperature sampling system includes a sampling pipeline, a carrier gas pipeline, a cooling unit, and a switching valve assembly; the sampling pipeline and the carrier gas pipeline are respectively connected to the switching valve assembly; Among them, the switching valve assembly includes a quantitative loop and a six-way valve connected to the quantitative loop. The quantitative loop is communicated with the sampling pipeline, and the six-way valve is communicated with the carrier gas pipeline; The cooling unit includes a cooling fan and a pipeline cooling device arranged on the sampling pipeline and the carrier gas pipeline; A diborane sample gas valve, a purge valve, and a vacuum pumping valve are arranged on the sampling pipeline.

2. The cryogenic injection system for diborane sample gas according to claim 1, wherein The low-temperature sampling system further includes a temperature and pressure measurement unit respectively arranged on the sampling pipeline and the carrier gas pipeline; The temperature and pressure measurement unit includes a pressure gauge and a thermometer.

3. The cryogenic injection system for diborane sample gas according to claim 2, wherein The pipeline cooling device is composed of a cooling device arranged in the pipeline and a circulating refrigeration instrument that provides a cooling medium for the cooling device.

4. The cryogenic injection system for diborane sample gas according to claim 3, wherein A cooling medium inlet and a cooling medium outlet are arranged on the cooling device, and the circulating refrigeration instrument is connected between the cooling medium inlet and the cooling medium outlet through a pipeline.

5. The cryogenic injection system for diborane sample gas according to claim 4, characterized in that, A carrier gas valve is arranged at the connection between the carrier gas pipeline and the six-way valve.

6. The cryogenic injection system for diborane sample gas according to claim 5, wherein An injection valve is arranged at the connection between the sampling pipeline and the quantitative loop.

7. The cryogenic injection system for diborane sample gas according to any one of claims 1 to 6, characterized in that The purge valve is connected to the purge gas.

8. The cryogenic injection system for diborane sample gas according to any one of claims 1 to 6, characterized in that, The cooling fan is arranged on the top of the six-way valve in the switching valve assembly.

9. The cryogenic injection system for diborane sample gas according to any one of claims 1 to 6, characterized in that, The vacuum pumping valve is connected to a vacuum pump.

10. The cryogenic injection system for diborane sample gas according to claim 9, characterized in that, The diborane sample gas valve is connected to a diborane sample gas cylinder.

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