Detection Method for Chloride Ions in Di-tert-butylaminosilane

Abstract

The present invention provides a method for detecting chloride ions in bis(tert-butylamino)silane, comprising the following steps: hydrolyzing a bis(tert-butylamino)silane sample to obtain a hydrolysis product; dissolving the hydrolysis product with an alkali solution to obtain a dissolution solution; diluting and making up the volume of the dissolution solution to obtain a dilution solution; subjecting the dilution solution to ultrasonic extraction and filtering the extraction solution to obtain a test filtrate; and detecting chloride ions in the test filtrate by ion chromatography to obtain the chloride ion concentration in the bis(tert-butylamino)silane sample. Using the present invention can solve the problem that in the current prior art, there is a lack of a method capable of accurately detecting chloride ions in bis(tert-butylamino)silane, so as to solve the problems such as easy blockage and damage of detection equipment, poor recovery rate, low accuracy and reproducibility in the current determination of chloride ions.

Description

Technical Field

[0001] The present invention relates to the technical field of ion detection, and more specifically, to a method for detecting chloride ions in bis(tert-butylamino)silane. Background Art

[0002] Bis(tert-butylamino)silane (BTBAS) is a silicon source precursor used for depositing silicon nitride and silicon oxide thin films at relatively low temperatures. The main advantages of this material are a relatively high thin film growth rate in the ALD process, and the deposited thin films have relatively low residual stress and good conformality. During the growth of silicon nitride thin films, with NH3 as the nitrogen source, since the chemical deposition of BTBAS-NH3 silicon nitride contains trace amounts of residual chlorine, the formation of a large amount of NH4Cl (ammonium chloride) is avoided. Ammonium chloride is the main source of defects in silicon nitride thin films. Volatile ammonium chloride and other chlorine by-products may cause the formation of particles and foggy films, and they can also deposit in the reactor exhaust pipe. These deposits may cause damage to wafers and pumps. Accurate detection of trace chloride ions in aminosilanes is particularly important, and a scientific and efficient method for detecting chloride ions needs to be developed.

[0003] In this regard, Zhang Ningwen et al. determined trace chloride ions in siloxanes by ion chromatography. It was mentioned in ("Determination of Trace Chloride Ions in Siloxanes by Ion Chromatography", Journal of Hangzhou Normal University (Natural Science Edition)) that siloxane samples were extracted by magnetic stirring with pure water, and the extraction solution was subjected to high-speed centrifugation separation and purification before ion chromatography analysis. The quantitative limit of chloride ions in the sample was 0.012 μg / g-1, the spiked recovery rate was between 94.3% and 112.2%, and the relative deviation of sample testing was 3.7%.

[0004] Liu Jun et al. proposed the optimization of conditions for the determination of halogens by oxygen bomb combustion-ion chromatography. It was mentioned in ("Optimization of Conditions for the Determination of Halogens by Oxygen Bomb Combustion-Ion Chromatography", Chemical Engineering & Equipment) that the orthogonal experiment method was used to optimize the analysis conditions for detecting halogens in plastics by oxygen bomb combustion-ion chromatography. The optimal conditions obtained were: the absorption solution was water with a volume of 10 mL, the oxygen filling pressure was at least 1 MPa, and the combustion standing time was 30 min. The results showed that the standard solutions of chlorine and bromine had a good linear relationship in the range of 0.5 mg / L to 10 mg / L, the correlation coefficient reached above 0.995, and the method detection limit was less than 30 mg / kg. The standard product numbered RMH002 developed by Longchang Intelligent Technology Research Institute was used for precision and accuracy verification. The recovery rates of chlorine and bromine contents were both between 96.5% and 101.6%, and the relative standard deviation RSD(n = 5) was less than 5%.

[0005] However, the above-mentioned pretreatment method for chloride ion detection is not applicable to the detection of chloride ions in bis(tert-butylamino)silane. Since bis(tert-butylamino)silane reacts violently with water to form a white silica amine salt substance, it is not suitable to use ultrapure water for extraction to determine chloride ions. After filtration, introducing it into ion chromatography analysis is likely to clog the injection system, and the recovery rate is relatively low. After the combustion of bis(tert-butylamino)silane in an oxygen bomb, silica is easily formed and adheres to the oxygen bomb combustion device, which is not easy to clean, and the recovery rate and reproducibility are poor.

[0006] In summary, there is currently a lack of a pretreatment method that can accurately detect chloride ions in bis(tert-butylamino)silane to solve the problems such as clogging and damage of detection equipment, poor recovery rate, and low accuracy and reproducibility in chloride ion determination in the aforementioned existing technologies. Summary of the Invention

[0007] In view of the above problems, the purpose of the present invention is to provide a method for detecting chloride ions in bis(tert-butylamino)silane to solve the problem that there is currently a lack of a method that can accurately detect chloride ions in bis(tert-butylamino)silane in the existing technologies, and to solve the problems such as easy clogging and damage of detection equipment, poor recovery rate, and low accuracy and reproducibility in current chloride ion determination.

[0008] The present invention provides a method for detecting chloride ions in bis(tert-butylamino)silane, including the following steps:

[0009] Hydrolyze the bis(tert-butylamino)silane sample to obtain a hydrolysis product;

[0010] Dissolve the hydrolysis product with an alkali solution to obtain a dissolved solution;

[0011] Dilute and make up the volume of the dissolved solution to obtain a diluted solution;

[0012] Perform ultrasonic extraction on the diluted solution and filter the extraction solution to obtain a test filtrate;

[0013] Use ion chromatography detection method to detect chloride ions in the test filtrate to obtain the chloride ion concentration in the bis(tert-butylamino)silane sample.

[0014] In addition, the preferred solution is that the hydrolysis of the bis(tert-butylamino)silane sample to obtain a hydrolysis product includes:

[0015] Add 0.5 - 2 mL of ultrapure water to 1 - 3 mL of the bis(tert-butylamino)silane sample for hydrolysis reaction;

[0016] After the hydrolysis reaction for 15 - 20 minutes, a hydrolysis product is obtained.

[0017] In addition, the preferred solution is that the alkali solution is a NaOH solution.

[0018] In addition, a preferred solution is that the hydrolysis product is dissolved with an alkali solution to obtain a solution, which includes:

[0019] Add 2 mL of a NaOH solution with a concentration of 100 g / L to the hydrolysis product for dissolution;

[0020] After the dissolution is carried out for 20 - 30 min, a solution is obtained.

[0021] In addition, a preferred solution is that the preparation method of the NaOH solution with a concentration of 100 g / L is as follows:

[0022] Dilute the reference reagent NaOH with 18 MΩ·cm ultrapure water so that the reference reagent NaOH is diluted to a concentration of 100 g / L to obtain a NaOH solution with a concentration of 100 g / L.

[0023] In addition, a preferred solution is that in the process of diluting and making up the volume of the solution to obtain a diluted solution,

[0024] Dilute and make up the volume of the solution to 30 - 40 mL with ultrapure water to obtain a diluted solution.

[0025] In addition, a preferred solution is that in the process of ultrasonically extracting the diluted solution and filtering the extract to obtain a test filtrate,

[0026] The ultrasonic extraction time of the diluted solution is at least 5 min.

[0027] In addition, a preferred solution is that in the process of ultrasonically extracting the diluted solution and filtering the extract to obtain a test filtrate,

[0028] After stirring the extract evenly with a tetrafluoro rod, filter the extract with a filter to obtain a test filtrate.

[0029] In addition, a preferred solution is that the filter is a 10 mL syringe 0.22 μm needle filter.

[0030] In addition, a preferred solution is that in the process of detecting chloride ions in the test filtrate by ion chromatography to obtain the chloride ion concentration in the bis - tert - butylaminosilane sample,

[0031] The eluent is 3.2 mMol Na2CO3·1.0 mMol NaHCO3;

[0032] The separation column is a Metrosep A supp5 150 / 4.0 anion chromatography column;

[0033] The standard curve concentration points are 0.01 μg / g, 0.05 μg / g, 0.2 μg / g, 0.5 μg / g, and 1 μg / g.

[0034] As can be seen from the above technical solution, the method for detecting chloride ions in bis-tert-butylaminosilane provided by the present invention transfers the chloride ions in the sample completely to the filtrate to be measured, i.e., the inorganic solvent, through hydrolysis, alkali dissolution, dilution and volume fixing, ultrasonic extraction and filtration of the bis-tert-butylaminosilane sample, etc., making the extraction efficiency higher; compared with the existing pretreatment methods for chloride ion detection, the filtrate to be measured obtained by the present invention has a low organic matter content and few particles, is more suitable for detection by an ion chromatograph, has a low matrix effect, and reduces the instrument maintenance cost; compared with the manual titration method, potentiometric titration method and coulometric method in the traditional chloride ion detection method, etc., the ion chromatography detection method adopted by the present invention optimizes the eluent concentration and flow rate, making the analysis stable, accurate, with a high recovery rate, a low detection limit and good reproducibility.

[0035] To achieve the above and related purposes, one or more aspects of the present invention include the features described in detail later. The following description and the accompanying drawings illustrate certain exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. Description of the Drawings

[0036] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easier to understand. In the drawings:

[0037] Figure 1 It is a flowchart of the method for detecting chloride ions in bis-tert-butylaminosilane according to an embodiment of the present invention. Detailed Embodiments

[0038] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is obvious that these embodiments can also be implemented without these specific details.

[0039] In view of the above-mentioned problems in the current prior art, there is a lack of a method that can accurately detect chloride ions in bis-tert-butylaminosilane to solve the problems such as easy blockage and damage of detection equipment, poor recovery rate, and low accuracy and reproducibility in the current chloride ion determination, a method for detecting chloride ions in bis-tert-butylaminosilane is proposed.

[0040] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings.

[0041] To illustrate the detection method and protection method of chloride ions in bis(tert-butylamino)silane provided by the present invention, Figure 1 The flow of the detection method of chloride ions in bis(tert-butylamino)silane according to an embodiment of the present invention is shown.

[0042] As Figure 1 shown, the detection method of chloride ions in bis(tert-butylamino)silane provided by the present invention includes the following steps:

[0043] S1. Hydrolyze the bis(tert-butylamino)silane sample to obtain a hydrolysis product.

[0044] As a preferred embodiment of the present invention, hydrolyzing the bis(tert-butylamino)silane sample to obtain a hydrolysis product includes:

[0045] Add 0.5 - 2 mL of ultrapure water to 1 - 3 mL of the bis(tert-butylamino)silane sample for hydrolysis reaction;

[0046] After the hydrolysis reaction for 15 - 20 min, a hydrolysis product is obtained.

[0047] During the hydrolysis reaction, the complete reaction of the bis(tert-butylamino)silane sample is stopped as the end point, generally for 15 - 20 min, to obtain a hydrolysis product.

[0048] S2. Dissolve the hydrolysis product with an alkali solution to obtain a dissolved solution.

[0049] As a preferred embodiment of the present invention, the alkali solution is a NaOH solution.

[0050] As a preferred embodiment of the present invention, dissolving the hydrolysis product with an alkali solution to obtain a dissolved solution includes:

[0051] Add 2 mL of a NaOH solution with a concentration of 100 g / L to the hydrolysis product for dissolution;

[0052] After the dissolution for 20 - 30 min, a dissolved solution is obtained.

[0053] As a preferred embodiment of the present invention, the preparation method of the NaOH solution with a concentration of 100 g / L is: dilute the reference reagent NaOH with 18 MΩ·cm ultrapure water so that the reference reagent NaOH is diluted to a concentration of 100 g / L to obtain a NaOH solution with a concentration of 100 g / L.

[0054] When dissolving the hydrolysis product with an alkali solution, after the complete digestion of the hydrolysis product, a dissolved solution is obtained, generally for 20 - 30 min.

[0055] S3. Dilute and make up the volume of the dissolved solution to obtain a diluted solution.

[0056] As a preferred embodiment of the present invention, in the process of diluting and making up the volume of the dissolution solution to obtain a dilution solution,

[0057] The dissolution solution is diluted and made up to 30 - 40 mL with ultrapure water to obtain a dilution solution.

[0058] S4. Ultrasonically extract the dilution solution, and filter the extract to obtain a filtrate to be measured.

[0059] As a preferred embodiment of the present invention, in the process of ultrasonically extracting the dilution solution, filtering the extract, and obtaining a filtrate to be measured,

[0060] The ultrasonic extraction time of the dilution solution is at least 5 min.

[0061] As a preferred embodiment of the present invention, in the process of ultrasonically extracting the dilution solution, filtering the extract, and obtaining a filtrate to be measured,

[0062] After stirring the extract evenly with a tetrafluoro rod, the extract is filtered with a filter to obtain a filtrate to be measured.

[0063] As a preferred embodiment of the present invention, the filter is a 10 mL syringe 0.22 μm needle filter.

[0064] Specifically, 10 mL of the ultrasonic supernatant is pipetted with a 10 mL syringe, filtered through a 0.22 μm needle filter, and the clarified filtrate is collected as the filtrate to be measured.

[0065] S5. Use ion chromatography detection method to detect chloride ions in the filtrate to be measured, and obtain the chloride ion concentration in the bis - tert - butylaminosilane sample.

[0066] As a preferred embodiment of the present invention, in the process of using ion chromatography detection method to detect chloride ions in the filtrate to be measured and obtain the chloride ion concentration in the bis - tert - butylaminosilane sample,

[0067] The eluent is 3.2 mMol Na2CO3·1.0 mMol NaHCO3;

[0068] The separation column is a Metrosep A supp5 150 / 4.0 anion chromatography column;

[0069] The standard curve concentration points are 0.01 μg / g, 0.05 μg / g, 0.2 μg / g, 0.5 μg / g, 1 μg / g;

[0070] The eluent flow rate is 0.7 mL / min.

[0071] To further explain and illustrate the technical effects of the method for detecting chloride ions in bis(tert-butylamino)silane provided by the present invention, the following specific embodiments are provided.

[0072] Example 1

[0073] Hydrolysis: Use a 1000 μL range dry pipette to transfer 1000 μL of bis(tert-butylamino)silane sample into a dried polytetrafluoroethylene crucible, add 0.5 mL of 18 MΩ·cm ultrapure water, let it stand for 15 min, and after the reaction is complete, a white hydrolyzate is formed.

[0074] Alkaline dissolution: Transfer 2 mL of 100 g / L NaOH solution into the polytetrafluoroethylene crucible, shake until the hydrolyzate reaction is complete, let it stand for 10 min, and dilute and make up the volume to 40 mL with ultrapure water.

[0075] Ultrasonic extraction: Place the polytetrafluoroethylene crucible in an ultrasonic instrument and ultrasonicate for 5 min to evenly distribute the chloride ions in the ultrasonic solution.

[0076] Filtration: Use a 10 mL syringe and a 0.22 μm filter head washed with ultrapure water to filter the ultrasonic extraction solution, and collect the filtrate for analysis using an ion chromatograph. The blank steps are the same.

[0077] Establish an ion chromatography standard curve. Dilute the chloride ion standard solution with ultrapure water. The standard concentration points are 0.01 μg / g, 0.05 μg / g, 0.2 μg / g, 0.5 μg / g, 1 μg / g, and the linear coefficient is greater than 0.9990. The ion chromatograph (IC-861, Metrohm, Switzerland) is used to determine the content of low-concentration anions. The working parameters of the ion chromatograph used in this example are shown in Table 1:

[0078]

[0079] Table 1

[0080] Apply the chloride ion detection method described in this example to the bis(tert-butylamino)silane samples of the same batch and perform parallel determinations 7 times. The results of the precision experiment are shown in Table 2.

[0081]

[0082] Table 2

[0083] Transfer 1 mL of bis(tert-butylamino)silane to 3 polytetrafluoroethylene crucibles respectively. No standard solution is added to the 1# crucible, and 0.5 mL of 100 μg / mL chloride ion standard solution is added to the 2# and 3# crucibles. Other treatment steps are the same as the previous steps in this example, and calculate the spiked recovery rate of chloride ions, as shown in Table 3.

[0084]

[0085] Table 3

[0086] The instrument detection limit of chloride ions calculated by the signal-to-noise ratio method is: 0.01 μg / g, the dilution factor in the method process is 40, and the method detection limit is 0.40 μg / g.

[0087] The above experimental data prove that the method provided by the present invention has a low detection limit, good precision, high recovery rate, is suitable for injection into an ion chromatography instrument, has no matrix interference, high accuracy, and meets the analysis requirements of chloride ions in bis(tert-butylamino)silane.

[0088] It can be seen from the above specific embodiments that the method for detecting chloride ions in bis(tert-butylamino)silane provided by the present invention, through processes such as hydrolysis, alkali dissolution, dilution and volume fixation, ultrasonic extraction and filtration of the bis(tert-butylamino)silane sample, completely transfers the chloride ions in the sample to the filtrate to be measured, that is, an inorganic solvent, making the extraction efficiency higher; compared with the existing pretreatment methods for chloride ion detection, the obtained filtrate to be measured in the present invention has a low organic matter content and few particulates, is more suitable for detection by an ion chromatography instrument, has a low matrix effect, and reduces the instrument maintenance cost; compared with traditional chloride ion detection methods such as manual titration, potentiometric titration and coulometric method, the ion chromatography detection method adopted in the present invention optimizes the eluent concentration and flow rate, making the analysis stable, accurate, with high recovery rate, low detection limit and good reproducibility.

[0089] As described above by way of example with reference to the drawings, the method for detecting chloride ions in bis(tert-butylamino)silane proposed according to the present invention is described. However, those skilled in the art should understand that various improvements can be made to the above-mentioned method for detecting chloride ions in bis(tert-butylamino)silane proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the appended claims.

Claims

1. A method for detecting chloride ions in bis-tert-butylaminosilane, characterized in that, It includes the following steps: Hydrolyze the di-tert-butylaminosilane sample to obtain a hydrolysis product; It includes: adding 0.5 - 2 mL of ultrapure water to 1 - 3 mL of the di-tert-butylaminosilane sample for hydrolysis reaction; after 15 - 20 minutes of hydrolysis reaction, a hydrolysis product is obtained; Dissolve the hydrolysis product with a NaOH solution to obtain a dissolution solution; it includes: adding 2 mL of a NaOH solution with a concentration of 100 g / L to the hydrolysis product for dissolution; after 20 - 30 minutes of dissolution, a dissolution solution is obtained; Dilute and make up the volume of the dissolution solution to obtain a dilution solution; during this process, dilute and make up the volume of the dissolution solution to 30 - 40 mL with ultrapure water to obtain a dilution solution; Perform ultrasonic extraction on the dilution solution and filter the extraction solution to obtain a test filtrate; Detect chloride ions in the test filtrate by ion chromatography to obtain the chloride ion concentration in the di-tert-butylaminosilane sample; among them, the conditions of the ion chromatography detection method include: The eluent is 3.2 mMol Na2CO3·1.0 mMol NaHCO3; The separation column is a Metrosep A supp5 150 / 4.0 anion chromatography column.

2. The method for detecting chloride ions in bis-tert-butylaminosilane according to claim 1, characterized in that, The preparation method of the NaOH solution with a concentration of 100 g / L is: Dilute the reference reagent NaOH with 18 MΩ·cm ultrapure water to dilute the reference reagent NaOH to a concentration of 100 g / L to obtain a NaOH solution with a concentration of 100 g / L.

3. The method for detecting chloride ions in bis-tert-butylaminosilane according to claim 1, characterized in that, During the process of performing ultrasonic extraction on the dilution solution and filtering the extraction solution to obtain a test filtrate, The ultrasonic extraction time of the dilution solution is at least 5 minutes.

4. The method for detecting chloride ions in bis-tert-butylaminosilane according to claim 1, characterized in that, During the process of performing ultrasonic extraction on the dilution solution and filtering the extraction solution to obtain a test filtrate, After stirring the extraction solution evenly with a tetrafluoro rod, filter the extraction solution with a filter to obtain a test filtrate.

5. The method for detecting chloride ions in bis-tert-butylaminosilane according to claim 4, characterized in that, The filter is a 10 mL syringe 0.22 μm needle filter.

6. The method for detecting chloride ions in bis-tert-butylaminosilane according to claim 1, characterized in that, During the process of detecting chloride ions in the test filtrate by ion chromatography to obtain the chloride ion concentration in the di-tert-butylaminosilane sample, The standard curve concentration points are 0.01 μg / g, 0.05 μg / g, 0.2 μg / g, 0.5 μg / g, 1 μg / g.

Images