Silicon substrate digestion solution, method for detecting trace metal impurities in organosilane, and kit

Abstract

The application provides a silicon substrate digestion solution, a detection method and a kit for trace metal impurities in organosilane. The silicon substrate digestion solution comprises, by mass fraction, 1-10 parts of hydrofluoric acid, 1-3 parts of hydrogen peroxide and 1-5 parts of water. The silicon substrate digestion solution provided by the application can completely digest organosilane to obtain a sample solution through the cooperation of the specific mass ratio of hydrofluoric acid, hydrogen peroxide and water, and when the sample solution is subjected to trace metal impurity detection, the sample solution will not block the atomizer nozzle and contaminate the atomization chamber, which is conducive to maintaining the precision and service life of the detection equipment, and the sample solution is not easily affected by the operation environment to introduce impurities, and the detection precision of trace metal impurities is further improved.

Description

Technical Field

[0001] This invention relates to the field of analytical detection technology, and more specifically, to a method and kit for detecting trace metal impurities in a silicon-based digestion solution and organosilanes. Background Technology

[0002] As integrated circuits advance towards ultra-large scale, the width and spacing of conductors are continuously decreasing. The signal delay effect (RC delay) caused by the parasitic resistance and capacitive coupling of interconnects has become a major bottleneck restricting the improvement of chip performance. Therefore, replacing traditional SiO2 dielectric with low dielectric constant (k) materials is an effective way to reduce parasitic capacitance and interconnect delay. High-purity dimethyldimethoxysilane (DMDMOS) is an important low-k precursor material used in high-end integrated circuit processes, mainly applied in the deposition of ultra-low dielectric constant dielectric layers between copper metal layers below 45nm process.

[0003] In integrated circuit manufacturing, the reduction in line size has greatly improved the speed and memory storage capacity of microelectronic devices, thus making the insulation requirements for interlayer dielectrics (ILDs) more stringent. Another major application of high-purity DMDMOS products is the deposition of insulating interlayer dielectrics in integrated circuit manufacturing.

[0004] Even trace impurities in DMDMOS can significantly impact the performance of products made using this silane. Metallic impurities can cause harmful doping effects and reduce the lifespan of electronic devices through migration processes. Therefore, accurate detection of trace impurities in DMDMOS is of great importance.

[0005] Currently, international manufacturers of electronic specialty gases in the United States, Japan, and South Korea primarily use ICP-MS analysis to detect trace impurities in electronic specialty gases. This invention also employs ICP-MS analysis; therefore, DMDMOS requires pretreatment of the sample before analysis to eliminate the influence of the complex silicon matrix, which is a technical challenge. Furthermore, the detection of trace impurities necessitates strict control over reagents, glassware, and environmental and human factors that may introduce impurities during sample preparation. Currently, sample digestion methods mainly include high-pressure digestion, microwave digestion, and direct digestion. The digestion method for silane samples primarily involves hydrolyzing the silane sample to generate fine silica particles. After the sample has completely evaporated, the impurities are adsorbed by the silica. The silica is then digested using clean hydrofluoric acid mist fumigation or hydrofluoric acid-ortho-acid reaction. The impurities are then fixed and adsorbed on the bottom of a clean crucible, and the impurities are collected and measured using a dilute acid solution after volume adjustment.

[0006] However, hydrofluoric acid fumigation or hydrofluoric acid-based digestion is not suitable for organosilanes, as the silicon matrix cannot be completely eliminated. A large amount of residual salts clogs the nebulizer nozzles, contaminates the nebulization chamber, and causes silicon matrix to adhere to the surfaces of the sampling and retrieval cones, affecting the equipment's sensitivity and lifespan. Furthermore, the samples are easily hydrolyzed, and the pretreatment or acid leaching process is greatly affected by human operation and the environment, making it easy for impurities to migrate in, thus making it unsuitable for the detection of trace impurities.

[0007] In view of this, the present invention is hereby proposed. Summary of the Invention

[0008] The main objective of this invention is to provide a silicon matrix digestion solution, a method for detecting trace metal impurities in organosilanes, and a kit to solve the problems of existing methods that use hydrofluoric acid mist fumigation or hydrofluoric acid-ortho-acid reaction to completely digest the silicon matrix. These methods not only clog the atomizer nozzle and contaminate the atomization chamber, affecting the sensitivity and lifespan of the equipment, but also easily introduce impurities during the detection process, making them unsuitable for the detection of trace impurities.

[0009] To achieve the above objectives, according to one aspect of the present invention, a silicon-based digestion solution is provided, comprising, by mass parts, 1 to 10 parts of hydrofluoric acid, 1 to 3 parts of hydrogen peroxide, and 1 to 5 parts of water.

[0010] Furthermore, the mass fractions of the above-mentioned hydrofluoric acid are 4 to 8 parts, the mass fractions of hydrogen peroxide are 1 to 2 parts, and the mass fractions of water are 1 to 2 parts.

[0011] To achieve the above objectives, according to one aspect of the present invention, a method for detecting trace metal impurities in organosilanes is provided. The method includes the following steps: Step S1, dissolving an organosilane sample in any of the silicon-based digestion solutions provided in the first aspect to obtain an organosilane digestion solution; Step S2, removing the solvent from the organosilane digestion solution to obtain sample residue; Step S3, dissolving the sample residue in nitric acid solution to obtain a sample solution to be tested; Step S4, using inductively coupled plasma mass spectrometry to detect the metal impurity content in the sample solution to be tested, and calculating the metal impurity content.

[0012] Furthermore, in step S1, the volume ratio of the organosilane sample to the silicon matrix digestion solution is 2:(3-5).

[0013] Furthermore, in step S1, the volume ratio of the organosilane sample to the silicon matrix digestion solution is 1:2.

[0014] Further, in step S2, the solvent is removed by heating.

[0015] Furthermore, the heating temperature is 120–140°C, and the time is 120–180 min.

[0016] Furthermore, heating is carried out under the protection of an inert gas, wherein the inert gas includes at least one of nitrogen, helium, or argon.

[0017] Further, in step S3, the mass concentration of the nitric acid solution is 0.5% to 2%.

[0018] Further, step S4 includes: step S41, using inductively coupled plasma mass spectrometry to detect the metal element standard solution and establish a metal element standard curve; step S42, using inductively coupled plasma mass spectrometry to detect the metal impurity content of the sample solution to be tested, calculating the concentration of metal impurities in the sample solution to be tested according to the elemental metal standard curve, and calculating the content of metal impurities in the organosilane sample based on the sampling amount and dilution measurement.

[0019] Furthermore, the metal element in the metal element standard solution is selected from at least one of Li, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, and Pb.

[0020] Furthermore, the organosilane sample is selected from at least one of methyltrimethoxysilane, dimethyldimethoxysilane, and trimethylmethoxysilane.

[0021] According to another aspect of the present invention, a detection kit for trace metal impurities in organosilanes is provided, comprising a silicon matrix digestion solution.

[0022] Furthermore, the test kit also includes standard solutions of metal elements.

[0023] By applying the technical solution of this application, the silicon-based digestion solution provided by this application, through the interaction of hydrofluoric acid, hydrogen peroxide and water in a specific mass ratio, can completely digest organosilanes to obtain a sample solution. When the sample solution is used for the detection of trace metal impurities, it will not clog the nebulizer nozzle or contaminate the nebulization chamber, which is beneficial to maintaining the accuracy and lifespan of the detection equipment. It is also less susceptible to the influence of the operating environment and the introduction of impurities, which is more conducive to improving the detection accuracy of trace metal impurities. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0025] As analyzed in the background section of this application, existing methods for digesting organosilanes using hydrofluoric acid mist fumigation or hydrofluoric acid-based acid reaction have the problem that the silicon matrix cannot be completely eliminated. This not only clogs the atomizer nozzle and contaminates the atomization chamber, affecting the sensitivity and lifespan of the equipment, but also makes it easy for impurities to be introduced during the detection process. In order to solve this problem, this application provides a silicon matrix digestion solution, a method for detecting trace metal impurities in organosilanes, and a kit.

[0026] In a first typical embodiment of this application, a silicon-based digestion solution is provided, which comprises, by mass parts, 1 to 10 parts of hydrofluoric acid, 1 to 3 parts of hydrogen peroxide, and 1 to 5 parts of water.

[0027] The silicon-based digestion solution provided in this application, through the interaction of hydrofluoric acid, hydrogen peroxide, and water in a specific mass ratio, can completely digest organosilanes to obtain a sample solution. When the sample solution is used for the detection of trace organic impurities, it will not clog the nebulizer nozzle or contaminate the nebulization chamber, which is beneficial to maintaining the accuracy and lifespan of the detection equipment. Furthermore, it is not easily affected by the operating environment and will not introduce impurities, which is more conducive to improving the detection accuracy of trace impurities.

[0028] In the silicon-based digestion solution provided in this application, the mass fraction of hydrofluoric acid is 1 part, 2 parts, 5 parts, 8 parts, 10 parts, or any combination of two values; the mass fraction of hydrogen peroxide is 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, or any combination of two values; and the mass fraction of water is 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or any combination of two values. In particular, when the mass fraction of hydrofluoric acid in the silicon-based digestion solution is 4 to 8 parts, the mass fraction of hydrogen peroxide is 1 to 2 parts, and the mass fraction of water is 1 to 2 parts, the efficiency of this silicon-based digestion solution in dissolving organosilanes is even higher.

[0029] The water mentioned above refers to water with a single metal impurity concentration of less than 10 ng / L, including but not limited to distilled water, deionized water, ultrapure water, and purified water, preferably ultrapure water, which refers to water with a resistivity of 18 MΩ·cm (25℃).

[0030] In a second typical embodiment of this application, a method for detecting trace metal impurities in organosilanes is also provided. The method includes the following steps: Step S1, dissolving the organosilane sample in a silicon matrix digestion solution to obtain a sample solution, wherein the silicon matrix digestion solution is any of the silicon matrix digestion solutions provided in the first typical embodiment above; Step S2, removing the solvent from the organosilane digestion solution to obtain sample residue; Step S3, dissolving the sample residue in nitric acid solution to obtain a sample solution to be tested; Step S4, using inductively coupled plasma mass spectrometry to detect the metal impurity content of the sample solution to be tested to obtain the metal impurity content.

[0031] The specific types of organosilanes mentioned above are not specifically limited, including but not limited to any one or a mixture of two or more of methyltrimethoxysilane, dimethyldimethoxysilane, and trimethylmethoxysilane.

[0032] The method for detecting trace metal impurities in organosilanes provided in this application uses a silicon-based digestion solution that can completely dissolve the organosilanes. During the detection of trace metal impurities, it will not clog the nebulizer nozzle or contaminate the nebulization chamber, which is beneficial to maintaining the accuracy and lifespan of the detection equipment. It is also not easily affected by the operating environment and will not introduce impurities. At the same time, it is easy to operate, simple in process, low in cost, high in accuracy, good in reproducibility, meets the requirements for spiked recovery rate, has a wide linear range, and low detection limit.

[0033] To further improve the digestion efficiency of organosilicon samples, in some embodiments, the volume ratio of organosilicon sample to silicon matrix digestion solution is 2:(3-5), such as 2:3, 1:2, 2:5, or any range of two values. In particular, a volume ratio of 1:2 between the organosilicon sample and the silicon matrix digestion solution is more conducive to improving digestion efficiency.

[0034] To further accelerate solvent removal, in some embodiments, heating is used to remove the solution, especially when the heating temperature is 120–140°C and the time is 120–180 min, which is more conducive to improving solvent removal efficiency. The heating temperature is such as 120°C, 125°C, 130°C, 135°C, 140°C or any range of two values, and the time is such as 120 min, 130 min, 150 min, 160 min, 180 min or any range of two values.

[0035] To reduce the ingress of impurities during the detection process, heating is preferably performed under the protection of an inert gas. The specific type of inert gas is not limited, including but not limited to any one or a mixture of two or more of nitrogen, helium, or argon.

[0036] To further improve detection accuracy, in some embodiments, the mass concentration of the nitric acid solution used in step S3 is 0.5% to 2%, such as 0.5%, 0.85%, 1%, 1.2%, 1.5%, 1.8%, 2%, or any range of two values.

[0037] In some embodiments, step S4 includes: step S41, using an inductively coupled plasma mass spectrometer to detect the metal element standard solution and establish a metal element standard curve, wherein the metal element in the metal element standard solution is selected from at least one of Li, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, and Pb; step S42, using an inductively coupled plasma mass spectrometer to detect the metal impurity content of the sample solution to be tested, calculating the concentration of metal impurities in the sample solution to be tested according to the elemental metal standard curve, and calculating the metal impurity content in the organosilane sample based on the sampling amount and dilution measurement.

[0038] In some instances, when establishing standard curves for metal elements, the inductively coupled plasma mass spectrometer (ICP-MS) is first checked and the equipment optimized. This includes: performing startup preparations; after the instrument ignites and stabilizes normally, routine performance checks are conducted. The instrument's stability and blank values ​​are checked with ultrapure water, and the equipment parameters are tuned and optimized using a 1 ng / g tuning solution containing Li, Y, Ti, Ce, and Co to maximize sensitivity covering the low, medium, and high mass number ranges and maintain optimal equipment performance and stability.

[0039] The specific type of inductively coupled plasma mass spectrometer mentioned above is not limited, such as the Agilent 7700ICP-MS. The method for establishing standard curves for metallic elements is not specifically limited; in some embodiments, the following steps are followed:

[0040] Agilent Part Number: 8500-6940 metal element standard solutions were used, with each element having a concentration of 10 mg / L. The solutions included Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Ti, U, V, and Zn. The mother liquor was diluted with 1 wt% nitric acid solution to prepare a 100 ng / g standard working solution. Following the standard curve preparation method, the calibration points were 1 wt% HNO3, 0.1 ng / g, 0.5 ng / g, 1 ng / g, 5 ng / g, and 10 ng / g. The linear coefficients for each element were all greater than 0.9995. The inductively coupled plasma mass spectrometer was set to standard mode, cold mode, or helium mode for each metal impurity. Standard solutions and blank solutions of different concentrations were introduced into the instrument through a PFA (a copolymer of small amounts of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene) injection system. Based on the response values ​​of different standard solutions and blank solutions obtained from the fully quantitative analysis, standard curve equations for each metal element were established. Subsequently, the sample solution and blank solution to be tested were detected using inductively coupled plasma mass spectrometry (ICP-MS) to obtain the corresponding response values. These response values ​​were then substituted into the standard curves of each element to obtain the concentration of metal impurities in the sample solution. Combined with the sample size and dilution calculations, the content of trace metal impurities in the organosilane sample was calculated.

[0041] To further improve the accuracy of the above-mentioned trace metal impurity content, in some embodiments, a blank solution corresponding to the sample solution to be tested is provided. This blank solution differs from the sample solution in that it does not contain any organosilicon sample. Subsequently, during the detection of trace metal impurities in organosilicones, standard solutions of different concentrations, the blank solution, and the sample solution are introduced into the instrument via a PFA injection system. Based on the response values ​​of the different standard solutions, blank solutions, and sample solutions obtained from the fully quantitative analysis, the impurity concentration of the sample solution is calculated by substituting these values ​​into the standard curve equations for each metal element.

[0042] In a third typical embodiment of this application, a kit for trace metal impurities in organosilanes is also provided, the kit comprising any of the silicon-based digestion solutions provided in the first typical embodiment described above.

[0043] In some embodiments of this application, the test kit also includes a metal element standard solution, which facilitates the rapid detection of metal impurities in organosilanes.

[0044] The beneficial effects of this application will be further illustrated below with reference to embodiments and comparative examples.

[0045] Example 1

[0046] This embodiment provides a silicon-based digestion solution comprising G6 grade hydrofluoric acid, G6 grade hydrogen peroxide, and ultrapure water in a mass ratio of 4:1:1.

[0047] Example 2

[0048] The difference between this embodiment and Embodiment 1 is that the digestion solution contains G6 grade hydrofluoric acid, G6 grade hydrogen peroxide and ultrapure water, and the mass ratio of the three is 8:2:1.

[0049] Example 3

[0050] The difference between this embodiment and Embodiment 1 is that the digestion solution contains G6 grade hydrofluoric acid, G6 grade hydrogen peroxide and ultrapure water, and the mass ratio of the three is 2:1:1.

[0051] Example 4

[0052] The difference between this embodiment and Embodiment 1 is that the digestion solution contains G6 grade hydrofluoric acid, G6 grade hydrogen peroxide and ultrapure water, and the mass ratio of the three is 10:1:1.

[0053] Example 5

[0054] The difference between this embodiment and Embodiment 1 is that the digestion solution contains G6 grade hydrofluoric acid, G6 grade hydrogen peroxide and ultrapure water, and the mass ratio of the three is 1:3:5.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that G6 grade hydrofluoric acid was not added to the digestion solution.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 is that G6 grade hydrogen peroxide was not added to the digestion solution.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 1 is that the mass ratio of G6 grade hydrofluoric acid, G6 grade hydrogen peroxide, and ultrapure water in the digestion solution is 15:1:1.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 1 is that the mass ratio of G6 grade hydrofluoric acid, G6 grade hydrogen peroxide and ultrapure water in the digestion solution is 1:4:6.

[0063] Experimental Example 1

[0064] The solubility of the digestion solutions provided in the above embodiments and comparative examples for the silicon substrate was tested respectively. The results are shown in Table 1 below. The specific steps included:

[0065] (1) Using a clean, dry pipette with a 1000 μL range, accurately transfer 2000 μL of dimethyldimethoxysilane sample into a polytetrafluoroethylene crucible. Add 4 mL of silicon matrix digestion solution in two portions using a PFA pipette, adding 2 mL of digestion solution each time. After adding the digestion solution, gently shake the crucible to make the solution more uniform. React at room temperature for 5 min to obtain organosilane digestion solution.

[0066] (2) Transfer the crucibles containing organosilane digestion solution to the base of the fumigator, open the crucible lid, cover it with a PTFE cover, cover it with a clean and dry plexiglass plate, introduce high-purity nitrogen gas from the side, place it on a 130°C heating plate for about 150 minutes to evaporate to dryness, and obtain the sample residue.

[0067] (3) While still hot, dissolve the sample residue and blank solution residue in 1.0wt% nitric acid solution and bring the volume to 3g. Shake well and cool to room temperature to obtain the sample solution to be tested.

[0068] Table 1

[0069]

[0070]

[0071] Example 6

[0072] This embodiment provides a method for detecting trace metal impurities in dimethyldimethoxysilane, which is performed according to the following steps:

[0073] (1) In a Class 1000 cleanroom with a Class 1000 workbench, accurately transfer 2000 μL of dimethyldimethoxysilane sample into a polytetrafluoroethylene crucible using a 1000 μL dry and clean pipette. Add a total of 4 mL of silicon-based digestion solution (the silicon-based digestion solution provided in Example 1) in two portions using a PFA pipette. Add 2 mL of digestion solution each time. After adding the digestion solution, gently shake the crucible to make the solution more homogeneous. React at room temperature for 5 minutes to obtain the organosilane digestion solution. A blank solution is also prepared simultaneously. The blank solution differs from the organosilane digestion solution in that it does not contain dimethyldimethoxysilane.

[0074] (2) Transfer the crucibles containing organosilane digestion solution and blank solution to the fumigation device base, open the crucible lid, cover it with a PTFE cover, cover it with a clean and dry plexiglass plate, introduce high-purity nitrogen gas from the side, place it on a 130°C heating plate for about 150 minutes to evaporate to dryness, and obtain the sample residue and blank solution residue.

[0075] (3) While still hot, dissolve the sample residue and blank solution residue in 1.0wt% nitric acid solution and bring the volume to 3g respectively. Shake well to obtain the sample solution and blank solution to be tested. Cool to room temperature and set aside.

[0076] (4) The Agilent 7700ICP-MS was optimized, and the optimized operating parameters are shown in Table 1 below. Standard curves for each metal element were established: Agilent Part Number: 8500-6940 metal element standard solution was used, with a concentration of 10 mg / L for each element, including Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Ti, U, V, and Zn. The standard solution was diluted with 1 wt% nitric acid solution to a standard working solution of 100 ng / g. According to the standard curve preparation method, the standard curves were prepared with the concentration points of 1 wt% HNO3, 0.1 ng / g, 0.5 ng / g, 1 ng / g, 5 ng / g, and 10 ng / g. The linear coefficients of each element were all greater than 0.9995. The inductively coupled plasma mass spectrometer (ICP-MS) was configured with standard mode, cold mode, or helium mode for each type of metal impurity. The blank solution and sample solution were introduced into the instrument via the PFA injection system. Based on the response values ​​of the blank solution and sample solution obtained from the fully quantitative analysis, the impurity concentration in the sample solution was calculated by substituting them into the standard curve equations for each metal element. Combined with the sample size and dilution measurement, the content of trace metal impurities in the organosilane sample was calculated. The precision results are shown in Table 2 below, and the same batch of samples was measured in parallel seven times.

[0077] Table 1

[0078] Instrument parameters Normal mode Cold mode Helium mode RF power (W) 1500 600 1500 Sampling depth / (mm) 8.0 18.0 8.0 Carrier gas flow rate (L / min) 0.72 0.82 0.74 Compensating gas flow rate (L / min) 0.41 0.67 0.48 Extract lens 1 / (V) 4.5 -188.3 4.4 Extract lens 2 / (V) -160.0 -13.5 -157.5 Number of repetitions 3 3 3

[0079] Table 2

[0080] element mass number model Mean (ng / g) RSD% Mg 24 Cold mode 0.062 4.78 Al 27 Cold mode 0.327 3.89 Ti 49 Normal mode 0.082 2.96 V 51 Helium mode 0.309 3.30 Cr 52 Helium mode 3.678 4.49 Mn 55 Cold mode 0.130 1.88 Fe 56 Cold mode 10.381 1.53 Co 59 Helium mode 0.380 3.36 Ni 60 Helium mode 4.805 2.21 Cu 63 Helium mode 0.860 1.30 Zn 66 Helium mode 20.265 3.08 Pb 208 Helium mode 0.209 2.16

[0081] As can be seen from Table 2, the relative standard deviation of each element is less than 10%, and the precision meets the requirements for trace impurity detection.

[0082] Examples 7-10

[0083] Examples 7-10 provide a method for detecting trace metal impurities in dimethyldimethoxysilane. The difference between the method and Example 6 is that the digestion solution provided in Examples 2-5 is used instead of the digestion solution provided in Example 1. The precision is shown in Table 3 below.

[0084] Table 3

[0085]

[0086] Verification Example 1

[0087] Currently, there are no relevant dimethyldimethoxysilane standards in the industry. To further verify the accuracy of the method, a spiked recovery test was conducted, processing six parallel samples. These parallel samples were test sample solutions prepared by digesting dimethyldimethoxysilane with unknown metal impurity content using the digestion solution provided in Example 1. The preparation method of the test sample solution was the same as that in Example 6. Three parallel samples were prepared without the metal mixed standard solution, and three parallel samples were prepared with 5.0 ng / g of the metal mixed standard solution. Other detection steps were the same as in Example 6. The spiked recovery rate of the metal impurities was calculated, as shown in Table 4. The lower value is the average metal content determined in the three parallel samples without the metal mixed standard solution, and the spiked value is the average metal content determined in the three parallel samples prepared with 5.0 ng / g of the metal mixed standard solution.

[0088] element This is a low value (ng / g). Spike value (ng / g) Dosage spiking (ng / g) Recovery rate % Mg 0.169 4.536 5.0 87.35 Al 0.427 4.873 5.0 88.91 Ti 0.167 4.172 5.0 80.11 V 0.138 4.854 5.0 94.30 Cr 2.324 7.046 5.0 94.44 Mn 0.093 4.373 5.0 85.60 Fe 6.314 10.483 5.0 83.37 Co 0.225 4.957 5.0 94.62 Ni 3.128 7.654 5.0 90.52 Cu 0.496 4.813 5.0 86.34 Zn 12.309 16.780 5.0 89.42 Pb 0.177 4.799 5.0 92.44

[0089] As can be seen from Table 4, the spiked recoveries of each element ranged from 80.11% to 94.62%, which meets the requirement of a recovery rate of 80% to 120%.

[0090] Verification Example 2

[0091] Using the digestion solution provided in Example 1 as the blank solution, 11 blank solutions to be tested were prepared. The specific steps were as follows: a crucible containing 4 mL of the blank solution was transferred to the base of a fumigator, the crucible lid was opened, a PTFE cover was placed on top, and a clean, dry plexiglass plate rinsed with pure water was placed on top. High-purity nitrogen gas was introduced from the side, and the mixture was placed on a heating plate at 130°C for about 150 minutes to evaporate to dryness, obtaining the blank solution residue. While still hot, the blank solution residue was dissolved in 1.0 wt% nitric acid solution and diluted to 3 g to obtain the blank solutions to be tested.

[0092] The 11 blank solutions to be tested were analyzed using an Agilent 7700 ICP-MS, and the standard deviation was calculated using the instrument's sensitivity (CPS). The method detection limit was set at 3 SD / k, in ng / g. The results showed that the detection limits for each metal element were Mg 0.021, Al 0.045, Ti 0.043, V 0.015, Cr 0.029, Mn 0.012, Fe 0.041, Co 0.010, Ni 0.015, Cu 0.033, Zn 0.027, and Pb 0.020. This indicates that the detection limits for each metal element are between 0.010 ng / g and 0.045 ng / g, with a detection limit less than 0.05 ng / g, meeting the requirements for trace impurity detection.

[0093] As can be seen from the above description, the above embodiments of the present invention achieve the following technical effects: The method for detecting trace metal impurities in organosilanes provided in this application uses a silicon matrix digestion solution that can completely dissolve organosilanes. The resulting sample solution will not clog the nebulizer nozzle or contaminate the nebulizer during the detection of trace metal impurities, which is beneficial to maintaining the accuracy and lifespan of the detection equipment. It is also not easy to introduce impurities due to the influence of the operating environment. At the same time, it is easy to operate, simple in process, low in cost, high in accuracy, good in reproducibility, meets the requirements for spiked recovery rate, has a wide linear range, and low detection limit.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting trace metal impurities in organosilanes, characterized in that, The detection method includes the following steps: Step S1: Dissolve the organosilane sample in a silicon matrix digestion solution at room temperature to obtain an organosilane digestion solution; wherein the silicon matrix digestion solution comprises 1-10 parts hydrofluoric acid, 1-3 parts hydrogen peroxide, and 1-5 parts water; the volume ratio of the organosilane sample to the silicon matrix digestion solution is 2:(3-5); the organosilane sample is selected from at least one of methyltrimethoxysilane, dimethyldimethoxysilane, and trimethylmethoxysilane; Step S2: Remove the solvent from the organosilane digestion solution to obtain sample residue; remove the solvent by heating; the heating temperature is 120~140℃ and the time is 120~180min; the heating is carried out under inert gas protection, the inert gas including at least one of nitrogen, helium or argon; Step S3: Dissolve the sample residue with nitric acid solution to obtain the sample solution to be tested; Step S4: The metal impurity content of the sample solution to be tested is detected by inductively coupled plasma mass spectrometry, and the content of the metal impurities is calculated. Step S4 includes: Step S41: Use inductively coupled plasma mass spectrometry to detect the standard solution of metal elements and establish a standard curve of metal elements; Step S42: The metal impurity content of the sample solution to be tested is detected by inductively coupled plasma mass spectrometry. The concentration of metal impurities in the sample solution to be tested is calculated according to the elemental metal standard curve. The content of metal impurities in the organosilane sample is calculated based on the sampling amount and dilution measurement. The metal element in the standard solution is selected from at least one of Li, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, and Pb.

2. The detection method according to claim 1, characterized in that, In step S1, the hydrofluoric acid is in the amount of 4-8 parts by mass, the hydrogen peroxide is in the amount of 1-2 parts by mass, and the water is in the amount of 1-2 parts by mass.

3. The detection method according to claim 1, characterized in that, In step S1, the volume ratio of the organosilane sample to the silicon matrix digestion solution is 1:

2.

4. The detection method according to claim 1, characterized in that, In step S3, the mass concentration of the nitric acid solution is 0.5-2%.

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