Method for detecting content of chloride ions in electronic-grade organic aluminum compound

Abstract

The invention relates to the technical field of chloride ion detection, in particular to a method for detecting the content of chloride ions in an electronic-grade organic aluminum compound. The detection method at least comprises the following steps: a sampling step; a sample treatment step: quenching the activity of the sample by using a quenching agent, heating to remove the quenching agent, and diluting with water; a sample detection step: detecting by adopting an ion chromatograph and setting a leacheate concentration gradient program; a data processing step: establishing a standard working curve equation between the chloride ion concentration and the response signal value; and the chloride ion content in the sample is calculated through the equation. According to the method for detecting the content of the chloride ions in the electronic-grade organic aluminum compound, the accuracy, safety and repeatability of the testing method can be improved, and meanwhile the detection method is low in detection limit and high in testing sensitivity.

Description

Technical Field

[0001] The invention relates to the technical field of chloride ion detection, and in particular to a method for detecting the chloride ion content in an electronic grade organic aluminum compound. Background Art

[0002] As an important precursor for the integrated circuit industry's atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD) and metal organic chemical vapor deposition (MOCVD) processes, organic aluminum compounds are widely used, especially for advanced processes below 45nm that require a High-K oxide layer as a dielectric material. With the development of miniaturized devices and the requirements for high aspect ratios, the use of High-K precursor materials including organic aluminum compounds (such as trimethylaluminum, triethylaluminum and dimethylaluminum hydride, etc.) has increased year by year. In the integrated circuit industry, chloride ions significantly affect the performance and durability of deposited films. Therefore, strictly controlling the chloride ion content in precursor materials has become a crucial quality indicator.

[0003] Chinese patent CN115979766A discloses a method for preparing a sample solution for the analysis of trace impurities in high-purity trimethylaluminum. The method uses a high-purity oxygen-nitrogen mixed gas method to oxidatively decompose trimethylaluminum, and then uses a nitric acid solution to digest it to obtain a sample solution, and the sample solution is used for ICP-MS testing. Chinese patent CN115166075B discloses a method for detecting the chloride ion content in an MO source. The method mixes a complexing agent with an MO source sample to be tested for complexing reaction, uses an extractant to extract the chloride ions, and then measures the Cl ion content according to ion chromatography. The above methods all use nitric acid to treat trimethylaluminum, and cannot rule out the possibility that nitrate and other impurities contained in the sample will react with Cl - The interference of peaks leads to inaccurate test results. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for detecting the chloride ion content in an electronic grade organoaluminum compound, which at least comprises the following steps:

[0005] Sampling procedures;

[0006] Sample processing steps: quench the sample activity with a quencher, heat to remove the quencher, and then dilute with water;

[0007] Sample detection steps: using an ion chromatograph and setting up an eluent concentration gradient program for detection;

[0008] Data processing steps: establish a standard working curve equation between chloride ion concentration and response signal value; calculate the chloride ion concentration in the sample through this equation.

[0009] In one embodiment, the sampling step includes: extracting a certain amount of electronic grade organoaluminum compound in a glove box and placing it in a sampling bottle, covering the bottle cap and transferring the sample to a weighing glove box.

[0010] In one embodiment, the electronic grade organoaluminum compound includes any one of trimethylaluminum, triethylaluminum, tributylaluminum, tri-tert-butylaluminum, triisobutylaluminum, dimethylaluminum hydride, dimethylaminoaluminum dihydride, tri(dimethylamino)aluminum, and triethoxyaluminum; preferably includes trimethylaluminum, triethylaluminum, tributylaluminum, tri-tert-butylaluminum, or triisobutylaluminum.

[0011] The electronic-grade organoaluminum compound product of the present invention is easily deliquescent and will deteriorate when exposed to air or a water-containing environment. Sampling and sample storage need to be performed in a glove box filled with inert gas. The shelf life of the electronic-grade organoaluminum compound is 24 months.

[0012] In one embodiment, the sample processing step comprises:

[0013] S1. Weigh 0.3-1g of sample into a PTFE cup with a lid, slowly add 3-10mL of solvent and 1-10mL of quencher and cover the PTFE cup;

[0014] S2. Heat the sample in the PTFE cup until the solvent and quencher are completely evaporated, then add ultrapure water to make the volume 10-15mL, let it stand and absorb the supernatant.

[0015] In one embodiment, the size of the covered polytetrafluoroethylene cup in step S1 is 50 mL.

[0016] In one embodiment, the solvent in step S1 is one or more of alkanes, ether, acetonitrile, and acetone.

[0017] In one embodiment, the solvent in step S1 is an alkane, including one or more of butane, n-pentane, n-hexane, and heptane.

[0018] In one embodiment, the quencher includes one or two of anhydrous ethanol, anhydrous methanol, and anhydrous acetic acid.

[0019] In one embodiment, the S1 step comprises: weighing 0.3-1 g of the sample into a PTFE cup with a lid, slowly adding 3-10 mL of n-hexane and 1-10 mL of anhydrous methanol and covering the PTFE cup lid.

[0020] In one embodiment, the S1 step comprises: weighing 0.3 g of sample into a PTFE cup with a lid, slowly adding 5 mL of n-hexane and 3 mL of anhydrous methanol and covering the PTFE cup lid.

[0021] In one embodiment, S2 is: adding 1-5 mL of eluent into a PTFE cup, heating the sample in the PTFE cup until the solvent and the quencher are completely evaporated, then adding ultrapure water to make the volume 10 mL, letting it stand and absorbing the supernatant.

[0022] In one embodiment, the temperature of the heating treatment in step S2 is 120°C-150°C.

[0023] In one embodiment, the eluent in step S2 is a KOH solution, and the concentration of the KOH solution is 0.1-100 mM.

[0024] In one embodiment, the resting time in step S2 is 1 h.

[0025] In one embodiment, the supernatant in step S2 is filtered through a 0.45 um filter head before use.

[0026] In one embodiment, the sample processing step comprises:

[0027] S1. Weigh 0.3g of sample into a PTFE cup with a lid, slowly add 5mL of n-hexane and 3mL of anhydrous methanol and cover the PTFE cup;

[0028] S2. Add 2 mL of 5 mM KOH solution to the PTFE cup, place it on a hot plate and heat the sample in the PTFE cup at 140 °C until the solvent and quencher are completely evaporated, then add ultrapure water to make the volume 10 mL, let it stand for 1 hour, then absorb the supernatant, and filter the supernatant through a 0.45 um filter head before use.

[0029] In one embodiment, the sample detection step uses an ion chromatograph to detect the sample processed in step S2.

[0030] In one embodiment, the condition parameters of the ion chromatograph include: the injection type is manual injection, the injection volume is 100 μL, the column flow rate is 0.5-2 mL / min, the column temperature is 25-35°C, the detector channel is ECD_1, ECD_Total, the sampling rate is 3-10 Hz, the detection cell temperature is 30-40°C, the suppressor type is AERS_4mm, and the eluent concentration gradient program is used for elution.

[0031] In one embodiment, the condition parameters of the ion chromatograph include: the injection type is manual injection, the injection volume is 100 μL, the column flow rate is 1 mL / min, the column temperature is 30°C, the detector channels are ECD_1, ECD_Total, the sampling rate is 5 Hz, the detection cell temperature is 35°C, the suppressor type is AERS_4mm, and the eluent concentration gradient program is used for elution.

[0032] In one embodiment, the eluent concentration gradient program includes: 0-7 min, the eluent concentration is 5 mM; 7-18 min, the eluent concentration is 5-20 mM; 18-20 min, the eluent concentration is 20-5 mM; 20 min, the eluent concentration is 5 mM.

[0033] In the eluent concentration gradient program of the present application, from 7 to 18 minutes, the concentration of the eluent increased from 5 mM to 20 mM at a constant rate, and the concentration increase rate was maintained at 15 mM / 11 min; from 18 to 20 minutes, the concentration of the eluent decreased from 20 mM to 5 mM at a constant rate, and the concentration decrease rate was maintained at 15 mM / 2 min.

[0034] In one embodiment, the standard solution in establishing the standard working curve equation is: standard substance for chlorine component analysis in water, purchased from Beijing North Weiye Metrology Technology Research Institute, specification: 1000ug / mL, 50mL, batch number 20221014;

[0035] The preparation process of the concentration points of the standard working curve solution is as follows: use a pipette to transfer 0.5mL of the standard substance for chlorine component analysis in water into a sample bottle, dilute to 50mL with ultrapure water, and count as the intermediate solution; then use a pipette to transfer 0.25mL, 0.5mL, 2.5mL, 5mL, and 10mL of the intermediate solution into the sample bottle, respectively, and dilute to 50mL with ultrapure water to obtain standard working curve solutions with concentration points of 50ug / L, 100ug / L, 500ug / L, 1000ug / L, and 2000ug / L.

[0036] The standard working curve equation is: y=0.001x+0010, and the correlation linear coefficient is R=0.9999; wherein x is the mass concentration of the element to be measured, in mg / L, and y is the peak area, in μS·min.

[0037] In one embodiment, the calculation formula of the chloride ion content of the sample in the data processing step is:

[0038]

[0039] Where:

[0040] A—the content of the element to be measured in the sample, in mg / L;

[0041] ρ—mass concentration of the element being measured in the sample solution, in μg / L;

[0042] ρ0—mass concentration of the element being measured in the sample blank solution, in μg / L;

[0043] V—the fixed volume of the sample after treatment, in mL;

[0044] m0—mass of the sample weighed, in g.

[0045] Beneficial Effects

[0046] 1. The present invention provides a method for detecting the chloride ion content in an electronic grade organoaluminum compound, thereby improving the safety and repeatability of the detection method.

[0047] 2. The method for detecting the chloride ion content in the electronic grade organoaluminum compound provided by the present invention adopts a specific sample treatment process, specifically, firstly treating with a quenching agent such as anhydrous ethanol or anhydrous methanol to quench the activity of trimethylaluminum, thereby improving the safety of the subsequent digestion process, and then digesting with a KOH solution to extract the chloride ions. On the one hand, the introduction of nitrate ions in the conventional scheme on the chloride ion peak and the influence on the accessories such as the chromatographic column and the suppressor in the ion chromatograph can be avoided; on the other hand, the high temperature digestion process caused by the use of aqueous solution digestion can be avoided, which will cause the HCl to be boiled dry, resulting in inaccurate test results of the chloride ions in the sample.

[0048] 3. The method for detecting the chloride ion content in the electronic grade organoaluminum compound provided by the present invention adopts ion chromatography to detect the sample, and at the same time establishes an eluent concentration gradient program. Through specific parameters such as eluent concentration and elution time, all anion peaks in the sample solution can flow out, and the chloride ion peak is not interfered by other anion peaks, thereby improving the accuracy and anti-interference of the test method.

[0049] 4. The method for detecting the chloride ion content in the electronic grade organoaluminum compound provided by the present invention has a low detection limit and high test sensitivity.

[0050] 5. The method for detecting chloride ions in electronic-grade organoaluminum compounds provided by the present invention has a high sample recovery rate and a high credibility of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is the detection spectrum of Example 1;

[0052] Figure 2 This is the detection spectrum of Comparative Example 2. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods for which specific conditions are not specified in the examples are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be purchased commercially.

[0054] Example 1

[0055] The present embodiment provides a method for detecting the chloride ion content in an electronic grade organoaluminum compound, comprising the following steps: a sampling step; a sample processing step: using a quencher to quench the activity of the sample, heating to remove the quencher and then diluting with water; a sample detection step: using an ion chromatograph and setting an eluent concentration gradient program for detection; a data processing step: establishing a standard working curve equation between the chloride ion concentration and the response signal value; and calculating the chloride ion content in the sample through the equation.

[0056] The sampling steps are as follows: randomly extracting a total amount of 10 g of trimethylaluminum (TMA) from a product packaging container in a glove box filled with inert gas and placing it in a sampling bottle, covering the bottle cap and transferring the sample to a weighing glove box.

[0057] The sample processing steps include:

[0058] S1. Weigh 0.3g of sample into a 50mL PTFE cup with a lid, slowly add 5mL of n-hexane and 3mL of anhydrous methanol and cover the PTFE cup;

[0059] S2. Add 2 mL of 5 mM KOH solution to the PTFE cup, place it on a hot plate and heat the sample in the PTFE cup at 140 °C until the solvent and quencher are completely evaporated, add ultrapure water to make the volume 10 mL, let it stand for 1 hour, then absorb the supernatant, and filter the supernatant through a 0.45 um filter head before use.

[0060] The sample detection step uses an ion chromatograph to detect the sample processed in step S2. The condition parameters of the ion chromatograph include: the injection type is manual injection, the injection volume is 100 μL, the chromatographic column flow rate is 1 mL / min, the column temperature is 30°C, the detector channels are ECD_1, ECD_Total, the sampling rate is 5 Hz, the detection cell temperature is 35°C, the suppressor type is AERS_4mm, and the eluent concentration gradient program elution.

[0061] The eluent concentration gradient program is: 0-7min, the eluent concentration is 5mM; 7-18min, the eluent concentration is 5-20mM; 18-20min, the eluent concentration is 20-5mM; 20min, the eluent concentration is 5mM.

[0062] The sample detection step also includes the preparation of a standard working curve.

[0063] The standard solution used in the preparation of the standard working curve is: standard substance for chlorine component analysis in water, purchased from Beijing North Weiye Metrology Technology Research Institute, specification: 1000ug / mL, 50mL, batch number: 20221014;

[0064] The preparation process of the concentration points of the standard working curve solution is as follows: use a pipette to transfer 0.5mL of the standard substance for chlorine component analysis in water into a sample bottle, dilute to 50mL with ultrapure water, and count as the intermediate solution; then use a pipette to transfer 0.25mL, 0.5mL, 2.5mL, 5mL, and 10mL of the intermediate solution into the sample bottle, respectively, and dilute to 50mL with ultrapure water to obtain standard working curve solutions with concentration points of 50ug / L, 100ug / L, 500ug / L, 1000ug / L, and 2000ug / L.

[0065] The standard working curve equation is: y=0.001x+0010, and the correlation linear coefficient is R=0.9999; wherein x is the mass concentration of the element to be measured, in mg / L, and y is the peak area, in μS·min.

[0066] The calculation formula of chloride ion content in the data processing step is:

[0067]

[0068] Where:

[0069] A—the content of the element to be measured in the sample, in mg / L;

[0070] ρ—mass concentration of the element being measured in the sample solution, in μg / L;

[0071] ρ0—mass concentration of the element being measured in the sample blank solution, in μg / L;

[0072] V—the fixed volume of the sample after treatment, in mL;

[0073] m0—mass of the sample weighed, in g.

[0074] Figure 1 This is the detection spectrum of this embodiment.

[0075] Comparative Example 1

[0076] The specific implementation of this comparative example is basically the same as that of Example 1, except that:

[0077] The detection method of this comparative example includes the following steps: a sampling step, a sample processing step, a sample detection step, and a data processing step.

[0078] The sample processing steps are:

[0079] S1. Weigh 0.3 g of trimethylaluminum into a 50 mL centrifuge tube, slowly add 5 mL of n-hexane and 3 mL of anhydrous methanol and cover the centrifuge tube;

[0080] S2. Add 9.7 mL of ultrapure water to the centrifuge tube, let it stand for 1 hour, and then absorb the supernatant.

[0081] The detection method provided in this example does not produce any peak in the sample.

[0082] Comparative Example 2

[0083] The specific implementation of this comparative example is basically the same as that of Example 1, except that:

[0084] The concentration gradient program of the eluent in this comparative example is: 0-7min, the concentration of the eluent is 5mM; 7-18min, the concentration of the eluent is 5-10mM; 18-20min, the concentration of the eluent is 10-5mM; 20min, the concentration of the eluent is 5mM.

[0085] In the eluent concentration gradient program in this comparative example, from 7 to 18 min, the concentration of the eluent increased from 5 mM to 10 mM at a constant rate, and the concentration increase rate was maintained at 5 mM / 11 min; from 18 to 20 min, the concentration of the eluent decreased from 10 mM to 5 mM at a constant rate, and the concentration decrease rate was maintained at 5 mM / 2 min.

[0086] Figure 2 This is the detection spectrum of this comparative example.

[0087] Performance Evaluation

[0088] 1. Method detection limit test

[0089] Referring to the sampling and sample retention method of Example 1, 10 samples of 0.3 g TMA were taken and detected by the detection method of Example 1, respectively, and were recorded as BLK-1, BLK-2, BLK-3, BLK-4, BLK-5, BLK-6, BLK-7, BLK-8, BLK-9, and BLK-10. The detection limits of chloride ions in each sample are shown in Table 1.

[0090] Table 1

[0091] Sample batch number Peak area (μS*min) BLK-1 0.0082 BLK-2 0.0060 BLK-3 0.0065 BLK-4 0.0070 BLK-5 0.0080 BLK-6 0.0082 BLK-7 0.0076 BLK-8 0.0079 BLK-9 0.0083 BLK-10 0.0079 average value 0.0076 Standard Deviation 0.0008 Instrument lod / ppb 2.170 Sample lod / ppm 0.0289

[0092] 2. Method repeatability test

[0093] The detection method of Example 1 was repeated 10 times to obtain the value of the chloride ion content A in the sample. The test results are shown in Table 2.

[0094] Table 2

[0095]

[0096]

[0097] 3. Spike recovery test

[0098] In order to verify the accuracy of the detection method, the sample in Example 1 was subjected to a spike recovery test. The test results are shown in Table 3.

[0099] Table 3

[0100]

[0101] Summary: By the attached Figure 1 It can be seen that the chromatographic peak obtained by the detection method established in this application has a complete peak shape, and there are no other interfering peaks around the main peak, and the elution peaks have good separation performance. Figure 2 It can be seen that after changing the concentration gradient setting, the elution peaks overlap seriously and the main peak of chloride ions is obviously interfered by other peaks, which will greatly weaken the accuracy and reliability of the test data.

[0102] As can be seen from Tables 1-3, the detection method of the present application has a low chloride ion detection limit and also exhibits excellent repeatability and accuracy, and has extremely good application value and industrial value for the detection of chloride ion content in electronic grade aluminum compounds.

Claims

1. A method for detecting the chloride ion content in an electronic grade organoaluminum compound, characterized in that: At least the following steps are included: Sampling procedures; Sample processing steps: quench the sample activity with a quencher, heat to remove the quencher, and then dilute with water; Sample detection steps: Use ion chromatograph and set eluent concentration gradient program for detection; Data processing steps: Establish a standard working curve equation between chloride ion concentration and response signal value; calculate the chloride ion content in the sample through this equation.

2. The method for detecting chloride ion content in electronic grade organoaluminum compounds according to claim 1, characterized in that: The electronic grade organoaluminum compound includes any one of trimethylaluminum, triethylaluminum, tributylaluminum, tri-tert-butylaluminum, triisobutylaluminum, dimethylaluminum hydride, dimethylaminoaluminum dihydride, tri(dimethylamino)aluminum, and triethoxyaluminum; preferably includes trimethylaluminum, triethylaluminum, tributylaluminum, tri-tert-butylaluminum, or triisobutylaluminum.

3. The method for detecting chloride ion content in electronic grade organoaluminum compound according to claim 1, characterized in that: The sample processing steps include: S1. Weigh 0.3-1g of sample into a PTFE cup with a lid, slowly add 3-10mL of solvent and 1-10mL of quencher and cover the PTFE cup; S2. Heat the sample in the PTFE cup until the solvent and quencher are completely evaporated, then add ultrapure water to make the volume 10-15mL, let it stand and absorb the supernatant.

4. The method for detecting chloride ion content in electronic grade organoaluminum compounds according to claim 1, characterized in that: The S2 is as follows: 1-5 mL of eluent is added to a PTFE cup, the sample in the PTFE cup is heated until the solvent and the quencher are completely evaporated, ultrapure water is added to make the volume to 10 mL, and the supernatant is aspirated after standing.

5. The method for detecting chloride ion content in electronic grade organoaluminum compound according to claim 3, characterized in that: The solvent in step S1 is one or more of alkanes, ether, acetonitrile and acetone.

6. The method for detecting chloride ion content in electronic grade organoaluminum compound according to claim 3, characterized in that: The solvent in step S1 is an alkane, including one or more of butane, n-pentane, n-hexane and heptane.

7. The method for detecting chloride ion content in electronic grade organoaluminum compounds according to claim 1, characterized in that: The quenching agent includes one or two of anhydrous ethanol, anhydrous methanol and anhydrous acetic acid.

8. The method for detecting chloride ion content in electronic grade organoaluminum compounds according to claim 1, characterized in that: The heating temperature in the sample treatment step is 120°C-150°C.

9. The method for detecting chloride ion content in electronic grade organoaluminum compound according to claim 1, characterized in that: The condition parameters of the ion chromatograph include: the injection type is manual injection, the injection volume is 100 μL, the chromatographic column flow rate is 0.5-2 mL / min, the column temperature is 25-35°C, the detector channels are ECD_1, ECD_Total, the sampling rate is 3-10 Hz, the detection cell temperature is 30-40°C, the suppressor type is AERS_4mm, and the eluent concentration gradient program is used for elution.

10. The method for detecting the chloride ion content in the electronic grade organoaluminum compound according to claim 1 or 9, characterized in that: The eluent concentration gradient program includes: 0-7min, the eluent concentration is 5mM; 7-18min, the eluent concentration is 5-20mM; 18-20min, the eluent concentration is 20-5mM; 20min, the eluent concentration is 5mM.

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