Method for detecting phosphorus element in trichlorosilane by ICP-MS

Abstract

The application discloses an ICP-MS detection method for phosphorus elements in trichlorosilane, and belongs to the field of high-purity electronic chemical analysis. The application adopts: low-temperature matrix digestion technology, quantitative formation of SiF6 2-complex, inhibition of silicon volatile loss; matrix matching calibration system, construction of calibration curve by weighted least squares method effectively corrects matrix interference; combined with high-resolution inductively coupled plasma mass spectrometry cascade strategy for detection technology screening strategy, successfully avoids complex matrix interference. Experiments show that the method for detecting phosphorus has a linear correlation coefficient R2>0.999, and the detection limit is as low as 0.02 ng / g, which meets ISO 17025 and semiconductor-grade material quality control standards, and is suitable for accurate quantitative analysis of ng / g-level phosphorus elements in high-purity trichlorosilane.

Description

Technical Field

[0001] This invention belongs to the field of analytical chemistry technology, specifically relating to a high-precision method for determining trace phosphorus content in trichlorosilane based on low-temperature matrix suppression-high-resolution mass spectrometry. Background Technology

[0002] Trichlorosilane, a core raw material for polycrystalline silicon, has phosphorus primarily present as PCl3 during its pretreatment process, possibly along with POCl3 and PCl5. Even trace amounts (e.g., ≤30 ng / g for solar-grade applications) can affect the electrical properties of polycrystalline silicon. While the current standard GB / T 28654-2018 employs inductively coupled plasma mass spectrometry (ICP-MS) for detection, its pretreatment requires steps such as acetonitrile complexation and nitrogen-based matrix volatilization, a process that takes several hours. Furthermore, phosphorus is easily lost during this volatilization process, leading to fluctuations in recovery rates. In addition, while alternative methods such as spectrophotometry are lower in cost, their sensitivity is insufficient (only reaching the mg / L level), failing to meet the requirements for high-purity detection. Summary of the Invention

[0003] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0004] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0005] Therefore, the purpose of this invention is to provide a complexation separation process for efficiently removing boron impurities from chlorosilanes. This invention is applicable to the rapid detection of ultra-trace (ng / g level) phosphorus impurities in the production of solar-grade and semiconductor-grade polycrystalline silicon. This method solves the problems of high phosphorus loss rate and cumbersome steps in traditional methods through innovative pretreatment technology, significantly improving detection efficiency and accuracy.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an ICP-MS method for detecting phosphorus in trichlorosilane, comprising,

[0007] (1) Low-temperature dissolution of samples: In a clean fume hood, dilute hydrofluoric acid pre-cooled to 0~5 ℃ is used as the dissolution medium. The dilute hydrofluoric acid is accurately transferred into the PFA container. The trichlorosilane sample to be tested is introduced into the pre-cooled HF system. After the sample is completely dissolved, it is further diluted with electronic grade dilute nitric acid.

[0008] (2) Matrix matching calibration and standard curve construction: The matrix standardization strategy was adopted. High-purity trichlorosilane was selected and subjected to the same pretreatment. Phosphorus standard solution was added in a gradient, with the concentration gradient covering 1~100 μg / L.

[0009] (3) Trace detection by triple quadrupole ICP-MS / MS: A high-resolution inductively coupled plasma tandem mass spectrometer equipped with a reaction cell was used. The MS Shift mode was selected for mass interference separation. Trace-level accurate detection of phosphorus was achieved in a complex matrix after low-temperature dissolution and dilution of trichlorosilane. The instrument detection limit was 0.02 ng / g.

[0010] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane described in this invention, the low-temperature dissolution involves preparing dilute hydrofluoric acid and dilute nitric acid using electronic-grade AA-10 49% HF and AA-10 50% nitric acid, respectively, with 18.2 MΩ·cm ultrapure water by volume. The concentrations of dilute hydrofluoric acid and dilute nitric acid are 0.5~1.0% and 1.0% v / v, respectively. The 1% nitric acid can be further used to inhibit the polymerization of the silicon matrix.

[0011] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane described in this invention, the trichlorosilane sample is completely dissolved in dilute hydrofluoric acid after dilution with electronic-grade dilute nitric acid. The solution is homogenized using a magnetic stirrer at a rate of 500-800 rpm, and complete dissolution is determined by visual clarification, so that trichlorosilane is completely dissociated into a soluble silicon-fluorine complex in the HF system.

[0012] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane described in this invention, the matrix matching calibration and standard curve construction are performed using high-purity trichlorosilane treated in the same way as the sample for the preparation of the standard curve, wherein the high-purity trichlorosilane requires a P content of <0.02 ng / g.

[0013] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane described in this invention, in the MS Shift mode, Q1 screens for target precursor ions, Q3 detects characteristic product ions, and in the dual mass screening mode, single-atom ions in the matrix are eliminated, and the space charge effect is compensated by dynamically adjusting the lens voltage.

[0014] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane according to the present invention, the instrument optimization before detection includes the following parameters:

[0015] Radio frequency power: 600~800 W; plasma volumetric flow rate: 15 L / min; auxiliary gas flow rate: 0.9 L / min; oxygen flow rate: 0.6 mL / min; nebulizer temperature: 2 ℃; sample rise rate: 20 r / min; nebulizer: high-salt nebulizer; sampling depth: 8 mm; acquisition mode: peak skipping; detection mode: automatic; number of measurement points per peak: 3; number of repetitions: 3.

[0016] As a preferred embodiment of the ICP-MS method for detecting phosphorus in trichlorosilane according to the present invention, a gradient concentration phosphorus standard solution is added to the trichlorosilane substrate solution by volume using a gravimetric method, with a background phosphorus content of <0.02 μg / kg. Quantitative analysis is performed by triple quadrupole ICP-MS / MS, a calibration curve is constructed, a regression equation is fitted, and the linear correlation coefficient R²≥0.999 is obtained. The accuracy of the method is verified by a spike recovery experiment, with a recovery rate of 95~105%.

[0017] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane described in this invention, the entire detection process is carried out in a strictly controlled clean environment.

[0018] As a preferred embodiment of the ICP-MS detection method for phosphorus in trichlorosilane according to the present invention, the method further includes routine calibration and maintenance of the detection instrument.

[0019] The beneficial effects of this invention are:

[0020] (1) High sensitivity: By adopting a dual mass screening strategy in MS / MS mode, it can effectively eliminate interfering ions in the matrix, greatly improve the detection sensitivity, and achieve accurate detection of trace (ng / g level) phosphorus in trichlorosilane.

[0021] (2) High accuracy: The establishment of a standardized matrix calibration system and the use of the standard addition method to obtain an accurate regression equation ensure the accuracy and reliability of the test results.

[0022] (3) Strong anti-interference ability: The synergistic effect of Q1 and Q3 can effectively eliminate the interference of single-atom ions such as Si⁺, Cl⁻, and F⁻ in the matrix, and improve the accuracy and reliability of the detection results. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0024] Figure 1 Calibration curve for phosphorus;

[0025] Figure 2 The phosphorus response values ​​are given under DRC reaction gas at different flow rates. Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0029] The core innovation of the method for determining phosphorus in trichlorosilane described in this invention lies in the ternary synergistic system of low-temperature dissolution-matrix matching-dynamic reaction cell detection, which is implemented in the following steps:

[0030] 1. Low-temperature dissolution of samples

[0031] In a clean fume hood, 1% dilute hydrofluoric acid, pre-cooled to 0–5 °C, was added to a PFA bottle and weighed accurately. Approximately 1.0 g of the trichlorosilane sample to be tested was injected into pre-cooled 1.0% HF solution at a rate of 0.2 mL / s using a pipette (PCTFE tip), and weighed accurately. A magnetic stirrer (200 rpm) was used to maintain homogeneity of the solution. The 1% hydrofluoric acid was prepared by weighing high-purity hydrofluoric acid (38.0% ± 1.0 wt%, TAMAPURE-AA-10) and 18.2 MΩ·cm ultrapure water.

[0032] 2. Gradient dilution

[0033] After complete dissolution in step 1 (visual clarification is required); transfer approximately 1.0 g of the solution to a second-stage PFA bottle and dilute to 10.0 g with 1% HNO3 (the dilution factor can be adjusted according to the content). The dilute nitric acid is prepared by weighing high-purity nitric acid (55.0% ± 1.0 wt% TAMAPURE-AA-10) and 18.2 MΩ·cm ultrapure water.

[0034] 3. Matrix Standardization Calibration System

[0035] High-purity trichlorosilane (P content < 0.02 ng / g) after double dilution was selected and treated according to steps 1-2 above. P mixed standard solutions were added respectively, and standard solutions containing phosphorus of 1.0, 2.0, 3.0, 5.0 and 20.0 ng / g were prepared by gravimetric method.

[0036] 4. Optimization of key equipment parameters

[0037] Ionization section: Core parameters such as RF power, compensation gas flow rate, and sampling depth were optimized through orthogonal experiments and response surface methodology. The RF power was set to 800 W to balance the ionization efficiency of the Si matrix and background noise. The auxiliary gas flow rate was 0.9 L / min, and a micro concentric nebulizer was used to control the aerosol particle size to 3-5 μm to improve the injection efficiency to 98%. Specific implementation parameters are shown in Table 1.

[0038] Table 1 Instrument Optimization Parameter Table

[0039]

[0040] Ion detection section: A three-stage mass spectrometry tuning process is adopted. The optimized parameters of the reaction cell are shown in Table 2. This effectively eliminates single-atom ions such as Si⁺, Cl⁻, and F⁻ in the matrix, significantly reducing noise interference and improving signal-to-noise ratio.

[0041] Table 2 shows the optimized parameters for the reaction tank.

[0042]

[0043] Note: In MS Shift mode, Q1 screens for target precursor ions (P⁻, m / z 30.9938), and Q3 detects characteristic product ions (PO₄²⁻). - (m / z 46.9938), to achieve dual quality screening.

[0044] Example 1

[0045] I. Solution Preparation

[0046] 1. Preparation of phosphorus standard working solution

[0047] Agilent multi-element calibration standards (model: 4#, containing 10 mg / L phosphorus, matrix: HNO3 / trace HF) were used. The standard stock solution was quantitatively transferred using a calibrated pipette and diluted with 1% nitric acid solution to obtain a working standard solution with a phosphorus concentration of 1.0 mg / L. The dilution process was completed in a Class 100 clean environment, and clean PFA instruments were used throughout the solution transfer process. (The above preparations were made using the gravimetric method).

[0048] 2. Preparation of acid reagent matrix

[0049] 1.0% hydrofluoric acid solution: Take high-purity hydrofluoric acid stock solution (TAMAPURE-AA-10 grade, concentration 38.0%±1.0 wt%) in a PFA container, and dilute it to the target concentration by weight using ultrapure water (resistivity ≥18.2 MΩ·cm), and monitor the temperature of the diluent in real time (ΔT≤±2 ℃).

[0050] 1.0% Nitric Acid Solution: Prepared by gravimetric method using high-purity nitric acid (TAMAPURE-AA-10 grade, concentration 55.0%±1.0 wt%) and ultrapure water. The preparation process was completed in a constant temperature mixer (25 ℃±0.5 ℃).

[0051] 3. Sample preparation

[0052] Measure 10.00 mL of pre-cooled 1.0% hydrofluoric acid solution (equilibrate in an ice-water bath at 0–5 °C for 10 min), transfer it to a 100 mL low-temperature resistant PFA reaction flask, and weigh and record the initial mass (A, accuracy 0.0001 g). Inject 1.00 mL of the trichlorosilane sample to be tested at a rate of 0.2 mL / s using an airtight syringe (accurately weigh and record the incremental mass B, accuracy 0.0001 g), and simultaneously start the magnetic stirring system (300±50 rpm) to maintain homogenization of the solution until the white solid is completely dissolved.

[0053] Transfer approximately 1.0 g of the solution to a secondary PFA dilution flask and weigh it; dilute to 10.0 g with 1.0% nitric acid solution and weigh to obtain the test solution.

[0054] Prepare a synchronous blank by following the steps above. The only difference between this blank and the test solution is that trichlorosilane sample is not added.

[0055] II. Detection Conditions for Inductively Coupled Plasma Mass Spectrometry

[0056] Ionization parameters: The atomizer, atomization chamber, and rectangular tube (center tube 1.5 mmPt) are all made of hydrofluoric acid resistant material; RF power: 600~800 W; plasma flow rate: 13~16 L·min -1 Atomizing gas flow rate: 0.7~1.0 L·min -1 Compensating gas flow rate: 0.9~1.30 L·min -1 Sample lifting speed: 15~25 rpm.

[0057] Instrument tuning: A tuning solution of 200 ng / L containing 6.940 Li, 9.012 Be, 23.98 Mg, 55.935 Fe, 114.904 In, 207.977 Pb, and 238.05 U was used to tune the instrument's rectangular tube position, nebulizer flow rate, supercone voltage, Omni Ring voltage, mass axis resolution, and mass axis position. The desired results were achieved when the sensitivity of 9.012 Be was greater than 2500, the sensitivity of 114.904 In was greater than 90000, the sensitivity of 238.05 U was greater than 55000, the resolution was within 0.78 ± 0.03 amu, and the RSD of oxides and doubly charged ions was within 0.03. Standard curves were then prepared, and samples were measured. Specific optimization parameters are shown in Table 1.

[0058] Ion detection section: A three-stage mass spectrometry tuning process is adopted to effectively eliminate single-atom ions such as Si⁺, Cl⁻, and F⁻ in the matrix, significantly reduce noise interference, and improve signal-to-noise ratio; specific instrument optimization parameters are shown in Table 2.

[0059] III. Preparation of Standard Curve and Sample Determination

[0060] After selecting a trichlorosilane sample with undetectable phosphorus and following the steps above, standard solutions of different concentration gradients were prepared using this solution as a substrate. These solutions were then analyzed using a high-resolution chemical multiplex quadrupole inductively coupled plasma mass spectrometer (PE5000G). A standard curve was constructed using the standard addition method to determine the phosphorus content in the test solution. A standard solution with the same concentration as the trichlorosilane standard solution was prepared using 1.0% nitric acid as a substrate. This solution was also analyzed using a high-resolution chemical multiplex quadrupole inductively coupled plasma mass spectrometer (PE5000G). A standard curve was constructed using the standard addition method to determine the phosphorus content in the blank sample. The phosphorus concentration in the sample solution was then calculated using the following formula:

[0061]

[0062] Where A is the amount of trichlorosilane sample (g); B is the weight of 1% hydrofluoric acid (g); C is the dilution factor of 1% HNO3 (g); C S C0 represents the concentration of the solution to be tested (ng / g); C0 represents the solubility of the blank solution (ng / g).

[0063] IV. Limit of Detection

[0064] 1. Select a trichlorosilane sample in which phosphorus was not detected, and prepare phosphorus standard solutions with concentrations of 1.0 ng / g, 2.0 ng / g, 3.0 ng / g, 5 ng / g, and 20 ng / g according to step one above. Perform detection according to steps two and three above, and obtain the linear correlation equation and correlation coefficient of phosphorus.

[0065] 2. Method Detection Limit: A standard curve was prepared and samples were measured using a blank sample as a base. The instrument detection limit for phosphorus was determined by repeating the blank sample N times (N=10). A trichlorosilane sample, in which phosphorus was not detected, was used, and the method detection line for boron was determined by repeating the standard curve N times (N=10). The correlation coefficient, linear equation, instrument detection limit, and method detection line of the calibration curve for phosphorus are shown in Table 3 below. The calibration curve for phosphorus is as follows: Figure 1 As shown.

[0066] Table 3. Linear equations, instrument detection limits, and detection lines of the method.

[0067] Example 2

[0068] I. Precision and Accuracy Testing

[0069] 1. Trichlorosilane samples 1#, 2#, and 3#, with average P contents of 2.89 ng / g, 5.82 ng / g, and 11.76 ng / g respectively, were measured in parallel 6 times according to the method in Example 1. The test results are shown in Table 4.

[0070] Table 4. Precision and accuracy of the method for testing P in trichlorosilane.

[0071]

[0072] As shown in Table 4, the relative standard deviation (RSD) of phosphorus content in the six consecutive determinations of trichlorosilane samples #1, #2, and #3 is ≤10%, indicating that the precision of this method meets the requirements for detection.

[0073] II. Spike Recovery Rate

[0074] In Implementation Case 2, during the preparation of the test solution 1 for #1 trichlorosilane, 2 ng / g, 5 ng / g, and 10 ng / g phosphorus standard solutions were added respectively; the method in Example 1 was used, and the determination results are shown in Table 5.

[0075] Table 5 Results of phosphorus element spiked recovery determination

[0076]

[0077] As shown in Table 5, the actual recovery rate of phosphorus in the sample spiked with the method is between 95% and 105%, which meets the testing requirements.

[0078] Comparative Example 1

[0079] Six samples, labeled A1, A2, A3, A4, A5, and A6, were prepared at room temperature using the method described in Example 1, with a phosphorus content of 5.82 μg / kg trichlorosilane. The samples were then analyzed under inductively coupled plasma mass spectrometry (ICP-MS) conditions. The difference from Example 2 was that the temperature range of 0–5 °C was changed to room temperature, and the samples were directly added to 1.0% hydrofluoric acid at (22 ± 2 °C). The phosphorus content in trichlorosilane was detected using ICP-MS at room temperature, and the results are shown in Table 6.

[0080] Table 6. Detection results of phosphorus in trichlorosilane at room temperature.

[0081]

[0082] As shown in Table 6 above, the precision of phosphorus content in trichlorosilane measured at room temperature (22±2℃) meets the standard, but the measured content is low.

[0083] Comparative Example 2

[0084] A phosphorus-free trichlorosilane sample was selected and prepared according to "I. Solution Preparation" in Example 1, with a phosphorus standard solution of 1.0 ng / g. Comparative detection was performed using MS / MS without DRC (STD mode) and MS / MS with DRC enabled in Shift mode. (Except for the use of DRC, everything else was consistent with the example). Calculations showed that the Si content in trichlorosilane is as high as 10-15%, and its hydrolysis produces... 30 Si 16 O 1 The H⁺ interference signal strength is comparable to that of a 10 μg / L spiked level. Without DRC: Direct detection of the m / z=30.98 region was performed, and observations were made. 30 Si 16 O 1 H⁺ and 31 P⁺ overlapping peaks; DRC enabled: Q1 screening 31 P⁺ (m / z = 30.9738), Q2 was converted to O₂ (0.6 mL / min) 31 P 16 O⁺ (m / z=46.9660), Q3 was used to detect the product ions. See Table 7 for details.

[0085] Table 7 Comparison of anti-interference performance before and after adopting DRC mode

[0086]

[0087] As shown in Table 7, the interference signal decreases significantly under DRC response mode. 30 Si 16 O 1H⁺ elimination >99.5% (compared to the non-DRC mode), signal-to-noise ratio improved by more than 100 times (from 1.3:1 to 400:1); the detection technology employs Q1 screening of precursor ions + Q2 collision / reaction + Q3 screening of product ions, successfully avoiding detection of complex matrices (such as Cl⁻, F⁻, and Si⁻ after trichlorosilane hydrolysis). 4+ )interference.

[0088] Under the above mode, the O2 flow rate was further optimized using a 1 μg / g P standard solution in the DRC(O2) test mode. The response values ​​(CPS) of P element were measured at different flow rates of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.8. Figure 2 As shown, the optimal DRC Nebulizer gas flow value was selected as 0.6 mL / min.

[0089] This invention proposes a breakthrough solution by directly dissolving the sample in dilute hydrofluoric acid (0.1-1%) at a low temperature (0-5 °C). The low temperature suppresses the hydrolysis side reaction of trichlorosilane, while a secondary dilution with dilute nitric acid is performed simultaneously. This is combined with a cascade strategy using high-resolution inductively coupled plasma mass spectrometry (ICP-5000G)—Q1 screening of precursor ions + Q2 collision / reaction + Q3 screening of product ions—to achieve ultra-trace (ppt-level) precise detection of phosphorus in complex matrices such as trichlorosilane. This method completely eliminates destructive steps such as acetonitrile complexation and nitrogen volatilization, reducing pretreatment time by more than 80% and increasing phosphorus recovery to 95-105%. Experiments show that the detection limit for phosphorus is as low as 0.02 ng / g, with a linear correlation coefficient R² > 0.999, and successfully avoids detection in complex matrices (such as Cl⁻, F⁻, and Si⁻ after trichlorosilane hydrolysis). 4 ⁺) Interference. Compared to the current national standard, this technology maintains ng / g level detection capability while significantly reducing operational complexity and equipment wear risk, providing technical support for real-time quality control of polysilicon production lines.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that several improvements and refinements can be made without departing from the principle of the present invention, and these improvements and refinements are within the protection scope of the present invention.

Claims

1. An ICP-MS method for the detection of phosphorus in trichlorosilane, characterized in that: include, (1) Low-temperature dissolution of samples: In a clean fume hood, dilute hydrofluoric acid pre-cooled to 0~5 ℃ is used as the dissolution medium. The dilute hydrofluoric acid is accurately transferred into the PFA container. The trichlorosilane sample to be tested is introduced into the pre-cooled HF system. After the sample is completely dissolved, it is further diluted with electronic grade dilute nitric acid. (2) Matrix matching calibration and standard curve construction: The matrix standardization strategy was adopted. High-purity trichlorosilane was selected and subjected to the same pretreatment. Phosphorus standard solution was added in a gradient, with the concentration gradient covering 1~100 μg / L. The high-purity trichlorosilane was required to have a P content of <0.02 ng / g. (3) Trace detection by triple quadrupole ICP-MS / MS: A high-resolution inductively coupled plasma tandem mass spectrometer equipped with a reaction cell was used. The MS Shift mode was selected for mass interference separation. Trace-level accurate detection of phosphorus was achieved in a complex matrix after low-temperature dissolution and dilution of trichlorosilane. The instrument detection limit was 0.02 ng / g.

2. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: The low-temperature dissolution process involves preparing dilute hydrofluoric acid and dilute nitric acid using electronic-grade AA-10 49% HF and AA-10 50% nitric acid, respectively, with 18.2 MΩ·cm ultrapure water by volume. The concentrations of dilute hydrofluoric acid and dilute nitric acid are 0.5~1.0% and 1.0% v / v, respectively. The 1% nitric acid can be further used to inhibit the polymerization of the silicon matrix.

3. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: The trichlorosilane sample was diluted with electronic-grade dilute nitric acid and completely dissolved in dilute hydrofluoric acid. The solution was homogenized using a magnetic stirrer at a rate of 500-800 rpm until it was completely dissolved, allowing the trichlorosilane to completely dissociate into a soluble silicon-fluorine complex in the HF system.

4. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: The matrix matching calibration and standard curve construction were performed using high-purity trichlorosilane, processed in the same way as the sample, for the preparation of the standard curve.

5. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: In MSShift mode, Q1 screens target precursor ions, and Q3 detects characteristic product ions. In dual mass screening mode, single-atom ions in the matrix are eliminated, and the space charge effect is compensated by dynamically adjusting the lens voltage.

6. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: Instrument optimization before testing; the optimization parameters are as follows: Radio frequency power: 600~800 W; plasma volumetric flow rate: 15 L / min; auxiliary gas flow rate: 0.9 L / min; oxygen flow rate: 0.6 mL / min; nebulization chamber temperature: 2 ℃; sample rise rate: 20 r / min; Nebulizer: High-salt nebulizer; Sampling depth: 8 mm; Acquisition mode: Peak skipping; Detection method: Automatic; Number of measurement points per peak: 3; Number of repetitions:

3.

7. The ICP-MS method for detecting phosphorus in trichlorosilane according to claim 1, characterized in that: Phosphorus standard solutions of varying concentrations were added to the trichlorosilane substrate solution by volume using a gravimetric method. The background phosphorus content was <0.02 μg / kg. Quantitative analysis was performed by triple quadrupole ICP-MS / MS. A calibration curve was constructed, and a regression equation was fitted. The linear correlation coefficient R² ≥ 0.

999. The accuracy of the method was verified by spiked recovery experiments, with a recovery rate of 95–105%.

8. The ICP-MS method for detecting phosphorus in trichlorosilane according to any one of claims 1 to 7, characterized in that: The entire testing process was conducted in a strictly controlled, ultra-clean environment.

9. The ICP-MS method for detecting phosphorus in trichlorosilane according to any one of claims 1 to 7, characterized in that: The method also includes routine calibration and maintenance of the testing instruments.

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