Gas chromatography method for determining purity of electronic gas trimethylsilane

Abstract

The invention discloses a gas chromatography method for measuring the purity of electronic gas trimethylsilane. The gas chromatography method comprises the following steps: preparing standard gas; testing the standard gas by adopting a gas chromatographic method to obtain the relationship between the component concentration of the standard gas and the corresponding peak area of each component; and calculating the concentration of each component in the to-be-detected sample gas according to the detection result of the to-be-detected sample gas and the relationship between the component concentration and the peak area, and further calculating the purity of the trimethylsilane. The method is easy to operate, high in accuracy and good in stability, the chromatographic purity of the electronic gas trimethylsilane can be accurately measured, and the defect of an electronic gas trimethylsilane analysis technology is overcome.

Description

Technical Field

[0001] The present application relates to the technical field of analysis and detection of silicon precursor products, and in particular to a gas chromatography method for determining the purity of electronic gas trimethylsilane. Background Art

[0002] Trimethylsilane (TMS, SiH(CH3)3), as an important organosilicon precursor electronic gas, plays an indispensable role in modern technology, particularly in advanced semiconductor manufacturing (such as depositing ultra-low dielectric constant copper diffusion barriers / etch stop layers and selective SiGe epitaxial growth), as well as in the synthesis of phase-change composites and specialty ceramics. The purity of electronic-grade TMS has a crucial impact on the performance, yield, and reliability of the final product. The presence of trace impurities and other silanes can lead to serious consequences, including degradation of deposited film performance, epitaxial defects, particle contamination, and material synthesis deviations.

[0003] Currently, there is no unified national or industry standard for determining the purity of the electronic gas trimethylsilane. In practice, it often relies on the supplier's internal specifications or the customized requirements of downstream users, and often draws on analytical methods for other silane gases. However, TMS has unique chemical properties (containing Si-H bonds and three methyl groups) and impurity spectrum: borrowing from standard GC methods for other silanes, its chromatographic column selection, detector configuration, pretreatment steps, quantitative calibration strategies, etc. often make it difficult to effectively separate, sensitively detect and accurately quantify all key impurities in TMS, especially for the detection limits of specific impurities in the TMS matrix. Therefore, it is urgent to develop a gas chromatography method for determining the purity of the electronic gas trimethylsilane. Summary of the Invention

[0004] Since there is no unified national or industry standard for measuring the purity of electronic gas trimethylsilane, this application proposes a gas chromatography method for measuring the purity of electronic gas trimethylsilane.

[0005] The scheme of this application is as follows:

[0006] A gas chromatography method for determining the purity of electronic gas trimethylsilane comprises the following steps:

[0007] Step S1. Configure standard gas;

[0008] Step S2. The standard gas is tested by gas chromatography to obtain the relationship between the concentration of the standard gas components and the corresponding peak area of ​​each component;

[0009] Step S3. Based on the measurement results of the sample gas to be tested and the corresponding relationship obtained in step S2, the concentration of each component in the sample gas to be tested is calculated, and the purity of trimethylsilane is calculated.

[0010] Preferably, the balance gas used to configure the standard gas in step S1 is nitrogen, and the configured standard gas is monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, or trimethylsilyl ether.

[0011] Preferably, the gas chromatography conditions include: the chromatographic column is a capillary column, 50m×0.53mm×3μm; carrier gas flow rate: 3mL / min; fuel gas flow rate: 40mL / min; auxiliary gas flow rate: 400mL / min; chromatographic column temperature: 70~130℃; injection port temperature: 70℃; split ratio: 15:1; injection volume: 1.0mL; sample pressure: 0.030MPa.

[0012] Preferably, the stationary phase of the capillary column is dimethylpolysiloxane.

[0013] Preferably, the temperature of the chromatographic column is raised by programmed temperature rise: the initial temperature is 70°C, maintained for 3 minutes; the temperature is raised to 130°C at a heating rate of 10°C / min, and maintained for 3 minutes.

[0014] Preferably, the carrier gas is helium; the fuel gas is hydrogen; and the supporting gas is air.

[0015] Preferably, the detector of the gas chromatograph is a hydrogen flame ionization detector, and the detector temperature is 220°C.

[0016] Preferably, the calculation formula for the concentration of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane and trimethylsilyl ether in the sample gas to be tested is:

[0017]

[0018] Where w i is the concentration of component i in the sample gas to be measured;

[0019] w si is the concentration of component i in the standard gas;

[0020] A i is the peak area of ​​component i in the sample gas to be measured;

[0021] A si is the peak area of ​​component i in the standard gas;

[0022] i is a monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane or trimethylsilyl ether component.

[0023] Preferably, the calculation formula for the purity of trimethylsilane in the sample gas to be tested is:

[0024] w%=100%-w1-w2-w3-w4-w5

[0025] Where w% is the purity of trimethylsilane in the sample gas to be tested;

[0026] w1 is the concentration of monosilane in the sample gas to be tested;

[0027] w2 is the concentration of tetramethylsilane in the sample gas to be tested;

[0028] w3 is the concentration of trimethylsilanol in the sample gas to be tested;

[0029] w4 is the concentration of trimethylchlorosilane in the sample gas to be tested;

[0030] w5 is the concentration of trimethylsilyl ether in the sample gas to be measured.

[0031] The gas chromatography method for determining the purity of the electronic gas trimethylsilane (TMS) disclosed in this application has the following advantages over the prior art:

[0032] This application systematically proposes and validates a gas chromatography method specifically for determining the purity of electronic-grade trimethylsilane for the first time. This method directly addresses the core pain point of the current industry's lack of a unified, authoritative purity testing standard. It provides a reliable, standardized core technical means for establishing a quality evaluation system for electronic-grade TMS, effectively resolving the lack of standards mentioned in the background art.

[0033] By selecting and optimizing chromatographic conditions (including a capillary column with a specific stationary phase, precise carrier gas / fuel gas / oxidant gas flow rate control, optimized programmed temperature gradient, injection parameters, etc.), effective separation of target impurities (monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, trimethylsilyl ether) and the main peak of TMS was achieved.

[0034] The external standard method is used for quantification, and the configured standard gas is used to establish an accurate peak area-concentration relationship, which improves the accuracy and reliability of impurity quantification and main purity calculation, and meets the stringent requirements of electronic-grade gases for trace impurity detection.

[0035] In summary, the present application discloses a gas chromatography method for determining the purity of electronic gas trimethylsilane, which is simple to operate, highly accurate, and stable. It can accurately determine the chromatographic purity of electronic gas trimethylsilane, thus filling the gap in electronic gas trimethylsilane analysis technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction to the drawings of the embodiments is given below.

[0037] Figure 1 is a gas chromatogram of the sample gas to be tested in Example 1;

[0038] Figure 2 This is the gas chromatogram of the sample gas to be tested in Example 2. DETAILED DESCRIPTION

[0039] In order to further illustrate the technical means and effects adopted by this application to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of this application are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0040] The present application is further described in detail below with reference to the accompanying drawings.

[0041] Example 1

[0042] A gas chromatography method for determining the purity of electronic gas trimethylsilane comprises the following steps:

[0043] (1) Configure standard gas

[0044] The mass fractions of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane and trimethylsilyl ether are accurately prepared to be 0.102%, 0.108%, 0.114%, 0.104% and 0.098% respectively. The balance gas is a mixed gas of nitrogen, which is the standard gas.

[0045] (2) Determination

[0046] The standard gas and the sample gas to be tested are tested separately by gas chromatography to obtain the gas phase measurement results of the standard gas and the gas phase measurement results of the sample gas to be tested.

[0047] Among them, the gas chromatography conditions are as follows: the chromatographic column is a capillary column, the stationary phase is dimethyl polysiloxane, 50m×0.53mm×3μm; helium is used as the carrier gas, the carrier gas flow rate is 3mL / min; hydrogen is used as the fuel gas, the fuel gas flow rate is 40mL / min; air is used as the supporting gas, the supporting gas flow rate is 400mL / min; programmed temperature is adopted: the initial temperature is 70℃, maintained for 3min; the temperature is increased to 130℃ at a heating rate of 10℃ / min, and maintained for 3min; the injection port temperature is 70℃; the split ratio is 15:1; the injection volume is 1.0mL; the sample pressure is 0.030MPa; the detector is a hydrogen flame ionization detector, and the detector temperature is 220℃.

[0048] (3) Calculate the concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether in the sample to be tested

[0049] The gas phase measurement results of the sample gas to be tested are as follows Figure 1As shown. Among them, monosilane has no peak; 6.425min is the retention time of tetramethylsilane, with a peak area of ​​7602; 7.189min is the retention time of trimethylsilanol, with a peak area of ​​5724; 8.035min is the retention time of trimethylchlorosilane, with a peak area of ​​113936; 9.774min is the retention time of trimethylsilyl ether, with a peak area of ​​33007. Substitute the data into the calculation formula for the concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether:

[0050]

[0051] The calculated concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether in the sample to be tested are shown in Table 1:

[0052] Table 1

[0053] Component name silane Tetramethylsilane Trimethylsilanol trimethylchlorosilane trimethylsilyl ether <![CDATA[w si ]]> 0.102％ 0.108％ 0.114％ 0.104％ 0.098％ <![CDATA[A si ]]> 1764 1870 1977 1802 1698 <![CDATA[A i ]]> 0 7602 5724 113936 33007 <![CDATA[w i ]]> 0％ 0.439％ 0.330％ 6.577％ 1.905％

[0054] (4) Calculate the purity of trimethylsilane in the sample to be tested

[0055] Substitute the data in Table 1 into the calculation formula for trimethylsilane purity:

[0056] w%=100%-w1-w2-w3-w4-w5

[0057] =100%-0%-0.439%-0.330%-6.577%-1.905%=90.749%

[0058] The purity of trimethylsilane in the sample to be tested was calculated to be 90.749%.

[0059] Example 2

[0060] A gas chromatography method for determining the purity of electronic gas trimethylsilane comprises the following steps:

[0061] (1) Configure standard gas

[0062] The mass fractions of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane and trimethylsilyl ether are accurately prepared to be 0.207%, 0.212%, 0.199%, 0.304% and 0.298% respectively. The balance gas is a mixed gas of nitrogen, which is the standard gas.

[0063] (2) Determination

[0064] The standard gas and the sample gas to be tested are tested separately by gas chromatography to obtain the gas phase measurement results of the standard gas and the gas phase measurement results of the sample gas to be tested.

[0065] Among them, the gas chromatography conditions are as follows: the chromatographic column is a capillary column, the stationary phase is dimethyl polysiloxane, 50m×0.53mm×3μm; helium is used as the carrier gas, the carrier gas flow rate is 3mL / min; hydrogen is used as the fuel gas, the fuel gas flow rate is 40mL / min; air is used as the supporting gas, the supporting gas flow rate is 400mL / min; programmed temperature is adopted: the initial temperature is 70℃, maintained for 3min; the temperature is increased to 130℃ at a heating rate of 10℃ / min, and maintained for 3min; the injection port temperature is 70℃; the split ratio is 15:1; the injection volume is 1.0mL; the sample pressure is 0.030MPa; the detector is a hydrogen flame ionization detector, and the detector temperature is 220℃.

[0066] (3) Calculate the concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether in the sample to be tested

[0067] The gas phase measurement results of the sample gas to be tested are as follows Figure 2 As shown. Among them, 3.849min is the retention time of monosilane, with a peak area of ​​2066; 6.485min is the retention time of tetramethylsilane, with a peak area of ​​2148; trimethylsilanol has no peak; 8.055min is the retention time of trimethylchlorosilane, with a peak area of ​​20661; 9.778min is the retention time of trimethylsilyl ether, with a peak area of ​​6424. Substitute the data into the calculation formula for the concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether:

[0068]

[0069] The calculated concentrations of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether in the sample to be tested are shown in Table 2:

[0070] Table 2

[0071] Component name silane Tetramethylsilane Trimethylsilanol trimethylchlorosilane trimethylsilyl ether <![CDATA[w si ]]> 0.207％ 0.212％ 0.199％ 0.304％ 0.298％ <![CDATA[A si ]]> 28511 30358 28294 42154 41616 <![CDATA[A i ]]> 2066 2148 0 20661 6424 <![CDATA[w i ]]> 0.015％ 0.015％ 0％ 0.149％ 0.046％

[0072] (4) Calculate the purity of trimethylsilane in the sample to be tested

[0073] Substitute the data in Table 2 into the calculation formula for trimethylsilane purity:

[0074] w%=100%-w1-w2-w3-w4-w5

[0075] =100%-0.015%-0.015%-0%-0.149%-0.046%=99.775%

[0076] The purity of trimethylsilane in the sample to be tested was calculated to be 99.775%.

[0077] The above description is merely a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A gas chromatography method for determining the purity of electronic gas trimethylsilane, characterized in that: The steps include: Step S1. Configure standard gas; Step S2. The standard gas is tested by gas chromatography to obtain the relationship between the concentration of the standard gas components and the corresponding peak area of ​​each component; Step S3. Based on the measurement results of the sample gas to be tested and the corresponding relationship obtained in step S2, the concentration of each component in the sample gas to be tested is calculated, and the purity of trimethylsilane is calculated.

2. A gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 1, characterized in that: The balance gas used for configuring the standard gas in step S1 is nitrogen, and the configured standard gases are monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane, and trimethylsilyl ether.

3. The gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 1, characterized in that: The gas chromatography conditions include: the chromatographic column is a capillary column, 50m×0.53mm×3μm; the carrier gas flow rate is 3mL / min; the fuel gas flow rate is 40mL / min; the auxiliary gas flow rate is 400mL / min; the chromatographic column temperature is 70-130°C; the injection port temperature is 70°C; the split ratio is 15:1; the injection volume is 1.0mL; and the sample pressure is 0.030MPa.

4. A gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 3, characterized in that: The stationary phase of the capillary column is dimethylpolysiloxane.

5. The gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 3, characterized in that: The temperature of the chromatographic column was raised by programmed heating: the initial temperature was 70° C., maintained for 3 min; the temperature was raised to 130° C. at a heating rate of 10° C. / min, and maintained for 3 min.

6. A gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 3, characterized in that: The carrier gas is helium; the fuel gas is hydrogen; and the supporting gas is air.

7. The gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 3, characterized in that: The detector of the gas chromatograph is a hydrogen flame ionization detector, and the detector temperature is 220°C.

8. The gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 2, characterized in that: The calculation formula for the concentration of monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane and trimethylsilyl ether in the sample gas to be tested is: Where w i is the concentration of component i in the sample gas to be measured; w si is the concentration of component i in the standard gas; A i is the peak area of ​​component i in the sample gas to be measured; A si is the peak area of ​​component i in the standard gas; i is a monosilane, tetramethylsilane, trimethylsilanol, trimethylchlorosilane or trimethylsilyl ether component.

9. The gas chromatography method for determining the purity of electronic gas trimethylsilane according to claim 2, characterized in that: The calculation formula for the purity of trimethylsilane in the sample gas to be tested is: w%=100%-w1-w2-w3-w4-w5 Where w% is the purity of trimethylsilane in the sample gas to be tested; w1 is the concentration of monosilane in the sample gas to be tested; w2 is the concentration of tetramethylsilane in the sample gas to be tested; w3 is the concentration of trimethylsilanol in the sample gas to be tested; w4 is the concentration of trimethylchlorosilane in the sample gas to be tested; w5 is the concentration of trimethylsilyl ether in the sample gas to be measured.

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