Method for detecting content of metal elements in electronic-grade titanium precursor

Abstract

This invention discloses a method for detecting the content of metal elements in electronic-grade titanium precursors, belonging to the field of semiconductor material metal ion detection technology. The method includes: sequentially oxidizing the titanium precursor to be tested with water and hydrogen peroxide to break down ligands, followed by digestion with a combination of nitric acid and hydrofluoric acid to obtain a clear matrix solution; preparing a standard working solution by adding standards to the sample solution using the standard addition method; and using ICP-MS / MS tandem mass spectrometry to detect zirconium and yttrium via mass transfer in O2 reaction mode, and copper via NH3 reaction mode, plotting a standard curve and calculating the content. This invention, through the synergistic effect of a two-step digestion strategy of oxidation followed by acid dissolution and the elimination of interference by reactive gas classification in tandem mass spectrometry, fundamentally solves the serious mass spectrometry interference of high-concentration titanium matrix on the detection of trace copper, zirconium, and yttrium, significantly reducing the instrument detection limit and background equivalent concentration to the ppt level, and has the advantages of high accuracy and good reproducibility.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material metal ion detection technology, and in particular to a method for detecting the metal element content in electronic-grade titanium precursors. Background Technology

[0002] When using high-purity titanium precursor materials as thin film materials, high levels of impurity elements can negatively impact film quality through multiple pathways, including electrical degradation, morphological deterioration, and process instability. This is especially critical in advanced semiconductor processes, where the level of control directly determines chip performance, reliability, and yield. For example, high copper content can cause the following effects: 1) Increased resistivity of the film, forming localized conductive channels or insulating traps; 2) Increased defect density in the film, affecting leakage current and reliability; 3) Copper adsorbs onto active sites on the precursor surface, inhibiting the saturation adsorption process of self-limiting reactions and reducing step coverage; 4) Influenced film formation rate suppression, increasing process time and cost. High zirconium content can cause the following effects: 1) Decreased K-value of the film, resulting in reduced storage capacity of the device; 2) Increased zirconium ion (Zr) content... 4+ Ionic radius (59 pm) and titanium ion (Ti 4+ The ions with highly similar radii (60.5 pm) readily substitute for titanium sites in the nitride lattice, forming deep-level defects and increasing resistivity. Furthermore, high yttrium content can lower the K-value of the thin film, reducing the device's storage capacity. Therefore, the accuracy of testing for copper, zirconium, and yttrium in high-purity titanium precursor materials is particularly important.

[0003] Currently, trace metal impurities in high-purity titanium precursor materials are generally measured using ICP-MS analysis. While most elements are tested in collision mode, this method cannot eliminate interference from polyatomic ions, oxides, double charges, hydrides, and isotopes in mass spectrometry, as well as matrix and physical effects from non-mass spectrometry sources. For example, when testing trimethoxy(pentamethylcyclopentadienyl)titanium (Star-Ti) samples, Ti... 4+ +16O 2+ For Cu(63) 2+ Ti and Cu(65) 2+ Interference, Ti 4+ +Ti 2+ For Zr (92) 4+ 94 4+ 96 4+ Interference is generated, 50Ti 4+ +40Ar 2+ For Zr (90) 4+ Interference is generated, 49Ti 4+ +40Ar 2+ For Y (89)3 +) Interference occurs. Existing testing methods still have many problems during testing. Matrix interference can lead to high local signal values ​​and high LOD values ​​for copper, zirconium, and yttrium in the sample solution, making it impossible to analyze the true value of impurity element content. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting the content of metal elements in electronic-grade titanium precursors, in order to solve the problem that traditional analytical methods cannot solve the serious interference of the titanium matrix with copper, zirconium and yttrium metal impurities, improve the accuracy and reliability of quantitative detection of copper, zirconium and yttrium metal impurities, and reduce the detection limit of metal impurities.

[0005] This invention provides a method for detecting the content of metal elements in electronic-grade titanium precursors, comprising the following steps: S1. Titanium precursor treatment: Add the titanium precursor to be tested into a container, add water, oxidant and inorganic acid in sequence, digest into a clear acidic solution, dilute and disperse the clear acidic solution evenly to obtain the sample solution. S2. Prepare standard working solutions by adding copper, zirconium, and yttrium standards to the sample solution using the standard addition method. S3. Plot the standard curve. Use an ICP-MS / MS testing instrument to detect the standard working solution and plot the standard curve and regression equation. S4. Sample solution detection: The sample solution was detected using an ICP-MS / MS instrument, and the contents of copper, zirconium, and yttrium in the titanium precursor were obtained according to the regression equation.

[0006] Preferably, in step S1, the titanium precursor includes at least one of titanium tetrachloride, tetra(dimethylamino)titanium, and trimethoxy(pentamethylcyclopentadienyl)titanium (Star-Ti).

[0007] More preferably, the titanium precursor is Star-Ti.

[0008] Preferably, the final concentration of the titanium precursor in the sample solution is 0.5–0.75 mg / mL.

[0009] Preferably, in step S1, the water is ultrapure water with a strength of 18.2 MΩ•cm; Preferably, the oxidant is hydrogen peroxide; Preferably, the inorganic acid is nitric acid and hydrofluoric acid in a volume ratio of 3:2; Preferably, the oxidant and inorganic acid are ultrapure reagents.

[0010] Preferably, the ratio of water, oxidant, and inorganic acid is 1 mL: 2 mL: 5 mL.

[0011] Preferably, in step S1, after digestion, the clarified acidic solution is diluted with ultrapure water to a final volume of 40-60 mL to obtain a clarified sample solution.

[0012] Preferably, in step S1, the digestion temperature is 150–200°C.

[0013] Preferably, in step S2, the preparation of the standard working solution specifically includes the following: Prepare standard solutions of Y, Zr, and Cu, each with a concentration of 10 mg / L; The standard solution was diluted with 18.2 MΩ•cm ultrapure water to prepare standard stock solutions with an elemental concentration of 100 μg / L. The standard stock solutions were added to the sample solutions using the standard addition method to obtain standard working solution 1 with an elemental concentration of 200 ng / L, standard working solution 2 with an elemental concentration of 500 ng / L, and standard working solution 3 with an elemental concentration of 1000 ng / L.

[0014] Preferably, when detecting Cu, Zr, and Y impurities in Star-Ti, the regression equation established by S3 is as follows: Selecting the [63->97] Cu and NH3 modes for Cu detection, the regression equation is y=7.3534. x+27.78, correlation coefficient R 2 =0.9995; Selecting the [89->105]Y and O2 modes to detect Y, the regression equation is y=42.1811. x+316.67, correlation coefficient R 2 =0.9988; Zr was detected using the [90->106] Zr and O2 modes, with a regression equation of y=147.3687. x+148.8867, correlation coefficient R 2 =0.9993.

[0015] Preferably, in step S4, when detecting Zr and Y metal impurities in the sample solution, the O2 mode is used, selecting [89->105]Y and [90->106]Zr or [92->108]Zr, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.4–1.5 kW, plasma gas flow rate 10.0–15.0 L / min, oxygen flow rate 20%–30%, extraction lens 1 voltage 3.0–4.0 V, compensation gas flow rate 0.40–0.48 L / min, nebulizing gas flow rate 0.6–0.7 L / min, energy discrimination voltage -8.0–-7.0 V, sampling depth 8–9.0 mm, extraction lens 2 voltage -110 V, nebulization chamber temperature 2.0 ± 0.5 °C, octet deflection voltage -4.0–-3.0 V, axial acceleration voltage 1.0–1.5 V.

[0016] More preferably, in step S4, when detecting Zr and Y metal impurities in the sample solution, the O2 mode is used, selecting [89->105]Y and [90->106]Zr, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.5kW, plasma gas flow rate 15.0 L / min, oxygen flow rate 30%, extraction lens 1 voltage 4.0V, compensation gas flow rate 0.48L / min, nebulizing gas flow rate 0.7L / min, energy discrimination voltage -7.0V, sampling depth 9.0mm, extraction lens 2 voltage -110V, nebulization chamber temperature 2.0℃, octet deflection voltage -3.0V, axial acceleration voltage 1.5V.

[0017] Preferably, in step S4, when detecting Cu metal impurities in the sample solution, the NH3 mode is used, selecting [63->97]Cu or [65->99]Cu, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.4–1.5 kW, plasma gas flow rate 10.0–15.0 L / min, helium flow rate 0.8–1.0 L / min, extraction lens 1 voltage 3.0–4.0 V, compensation gas flow rate 0.35–0.38 L / min, nebulizing gas flow rate 0.6–0.7 L / min, energy discrimination voltage -10–-8.0 V, sampling depth 8–9.0 mm, ammonia flow rate 60%–65%, extraction lens 2 voltage -250 V, nebulization chamber temperature 2.0 ± 0.5 °C, octet deflection voltage -0.6–-5.0 V, axial acceleration voltage 0.4–0.5 V.

[0018] More preferably, in step S4, when detecting Cu metal impurities in the sample solution, the NH3 mode is used, [63->97]Cu is selected, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.5kW, plasma gas flow rate 15.0 L / min, helium flow rate 1.0 L / min, extraction lens 1 voltage 4.0V, compensation gas flow rate 0.38L / min, nebulizing gas flow rate 0.7L / min, energy discrimination voltage -8.0V, sampling depth 9.0mm, ammonia flow rate 65%, extraction lens 2 voltage -250V, nebulization chamber temperature 2.0℃, octet deflection voltage -5.0V, axial acceleration voltage 0.5V.

[0019] Preferably, the sample preparation and testing process is carried out in a testing environment with at least a Class 1000 cleanroom and a Class 100 cleanroom.

[0020] The beneficial effects of this invention are: This invention employs a two-step pretreatment strategy—first oxidizing and destroying organic ligands in the sample, then acid-dissolving and digesting—to effectively solve the physical interference caused by incomplete digestion of titanium precursors containing organic ligands. This yields a clear solution with a pure and uniformly distributed matrix. Furthermore, to address the severe mass spectrometric interference of high-concentration titanium matrix-derived polyatomic ions on Cu, Zr, and Y elements, an ICP-MS / MS classification reaction gas mass transfer strategy is used to transfer the analyte ions to the interference-free product mass number for detection, fundamentally eliminating mass spectrometric overlap interference. The synergistic effect of pretreatment in controlling matrix morphology and mass spectrometry in eliminating interfering ions significantly reduces the background equivalent concentration and instrument detection limit for copper, zirconium, and yttrium, thereby significantly improving the accuracy, reliability, and sensitivity of quantitative detection of trace metal impurities. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] A method for detecting the content of metallic elements in electronic-grade titanium precursors, comprising the following steps: S1. Titanium precursor treatment: Add the titanium precursor to be tested into a container, add water, oxidant and inorganic acid in sequence, digest into a clear acidic solution, dilute and disperse the clear acidic solution evenly to obtain the sample solution. S2. Prepare standard working solutions by adding copper, zirconium, and yttrium standards to the sample solution using the standard addition method. S3. Plot the standard curve. Use an ICP-MS / MS testing instrument to detect the standard working solution and plot the standard curve and regression equation. S4. Sample solution detection: The sample solution was detected using an ICP-MS / MS instrument, and the contents of copper, zirconium, and yttrium in the titanium precursor were obtained according to the regression equation.

[0023] By adopting the above technical solutions, the electronic-grade titanium precursor exhibits a stable molecular structure and strong hydrophobicity. If the traditional acid dissolution method is used directly, the organic ligands encapsulate the titanium core, forming a hydrophobic barrier that prevents effective acid penetration, leading to incomplete digestion, solution turbidity, and solid-liquid separation. This solution employs a two-step method: oxidation followed by acid dissolution. Ultrapure water first wets the sample surface. Hydrogen peroxide, under heating conditions, generates strong oxidizing free radicals that break the C-Ti and CO bonds of the organic ligands, causing oxidative degradation of the organic framework. Subsequently, a mixed acid of nitric acid and hydrofluoric acid completely dissolves the titanium matrix at high temperature, allowing HF and Ti to react. 4+ Formation of stable [TiF6] 2- The complex prevents hydrolysis and precipitation. This timing design avoids the intense competition between oxidation and acid dissolution reactions, achieving mild oxidation of organic matter and complete dissolution of the titanium matrix, resulting in a clear, transparent, and uniformly dispersed sample solution. This fundamentally eliminates the physical interference caused by the carbonization and deposition of undigested organic matter in ICP plasma.

[0024] At the interference cancellation level, the standard addition method of S2-S4 synergistically combines with the ICP-MS / MS classified reactive gas mass transfer strategy. High-concentration titanium matrices generate severe polyatomic ion interference in ICP plasma. Traditional He collision modes can only reduce interference through kinetic energy discrimination, failing to fundamentally separate ions with overlapping mass numbers, resulting in extremely high background signals and severely deteriorated detection limits. This scheme addresses the chemical differences in the interference experienced by Cu, Zr, and Y elements, employing a classified reactive gas strategy. + Transfer to Cu(NH3)2 via cluster reaction of NH3 + (m / z 97), Zr + and Y + The oxidation reaction of O2 is used to transfer the components to ZrO. + (m / z 106) and YO + (m / z 105) This method transfers the analyte from the primary mass number region with dense interference to the "interference-free region" for detection. The standard addition method involves directly adding the standard substance to a solution that is completely identical to the sample matrix, so that the standard curve and sample determination are carried out under the same matrix effect conditions. This effectively compensates for the influence of high-concentration titanium matrix on plasma state and ion transport efficiency, and avoids the quantitative deviation caused by matrix differences in the external standard method.

[0025] In some embodiments, in step S1, the titanium precursor includes at least one of titanium tetrachloride, tetra(dimethylamino)titanium, and trimethoxy(pentamethylcyclopentadienyl)titanium (Star-Ti); more preferably, the titanium precursor is Star-Ti.

[0026] The final concentration of the titanium precursor in the sample solution was 0.5–0.75 mg / mL.

[0027] By adopting the above technical solutions, the three titanium precursors represent three typical electronic-grade titanium sources in terms of molecular structure: inorganic halides, organic amine compounds, and organic cyclopentadienyl compounds. The final concentration of the titanium precursor in the sample solution is limited to 0.5–0.75 mg / mL. This is based on the consideration that high-concentration titanium matrices will produce severe space charge effects and polyatomic ion interference in ICP-MS / MS plasma. Too low a concentration results in insufficient signal intensity and decreased detection sensitivity, while too high a concentration exacerbates matrix effects and complicates mass spectrometry interference.

[0028] In some embodiments, in step S1, the water is ultrapure water with a strength of 18.2 MΩ•cm; The oxidizing agent is hydrogen peroxide; The inorganic acids are nitric acid and hydrofluoric acid in a volume ratio of 3:2; The oxidizing agent and inorganic acid are ultrapure reagents.

[0029] The ratio of water, oxidant, and inorganic acid used is 1 mL: 2 mL: 5 mL.

[0030] By employing the above technical solution, hydrogen peroxide is used as an oxidant to efficiently destroy the organic ligands in the titanium precursor, while the combination of nitric acid and hydrofluoric acid ensures the complete digestion of the titanium matrix. The synergistic effect of the reagent combination guarantees the stability and thoroughness of the pretreatment. The volume ratio of water, oxidant, and inorganic acid is 1 mL: 2 mL: 5 mL, which ensures both sufficient oxidation of the organic matter by the oxidant and provides sufficient acidity to achieve complete dissolution and stable complexation of the titanium.

[0031] In some embodiments, in step S1, after digestion, the clarified acidic solution is diluted with ultrapure water to a final volume of 40-60 mL to obtain a clarified sample solution.

[0032] The digestion temperature is 150–200℃.

[0033] By adopting the above technical solution, the synergistic logic of the two-step pretreatment method is enhanced through the oxidation-acid dissolution sequence and a suitable digestion temperature. The use of ultrapure reagents avoids contamination from external reagents, further ensuring the accuracy of trace detection. The temperature range of 150–200℃ was optimized and determined. Below 150℃, the organic ligands are not completely oxidized, and the titanium matrix is ​​not sufficiently dissolved; above 200℃, the PTFE container is prone to deformation, and excessive HF volatilization leads to a decrease in the stability of the titanium complex. After digestion, the volume is adjusted to 40–60 mL, preferably 50 mL, so that the titanium concentration in the final solution is 0.5–0.75 mg / mL, ensuring that the matrix effect is under control during subsequent ICP-MS / MS detection.

[0034] In some embodiments, step S2, preparing the standard working solution specifically includes the following: preparing standard solutions of Y, Zr and Cu, each with a concentration of 10 mg / L; The standard solution was diluted with 18.2 MΩ•cm ultrapure water to prepare standard stock solutions with an elemental concentration of 100 μg / L. The standard stock solutions were added to the sample solutions using the standard addition method to obtain standard working solution 1 with an elemental concentration of 200 ng / L, standard working solution 2 with an elemental concentration of 500 ng / L, and standard working solution 3 with an elemental concentration of 1000 ng / L.

[0035] In some preferred embodiments, step S2, preparing the standard working solution, specifically includes the following: Prepare standard solution 1 and standard solution 2. Standard solution 1 contains the elements Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, Re, Sc, Se, Sm, Sr, Tb, Th, Tl, Tm, U, V, Y, Yb, and Zn, with a concentration of 10 mg / L. Standard solution 2 contains the elements Ag, Ge, Hf, Mo, Nb, Sb, Si, Sn, Ta, Te, Ti, W, and Zr, with a concentration of 10 mg / L. Standard solutions 1 and 2 were diluted with 18.2 MΩ•cm ultrapure water to prepare standard stock solutions 1 and 2, each with an elemental concentration of 100 μg / L. Standard stock solutions 1 and 2 were added to the sample solution using the standard addition method to obtain standard working solution 1 with an elemental concentration of 200 ng / L, standard working solution 2 with an elemental concentration of 500 ng / L, and standard working solution 3 with an elemental concentration of 1000 ng / L.

[0036] By adopting the above technical solutions and using the standard addition method to prepare the standard working solution, the matrix effect and signal suppression caused by the high concentration of titanium matrix can be effectively compensated. In the external standard method, the titanium matrix may change the excitation temperature, electron density, and ionization efficiency of the plasma, resulting in significant differences in the signal responses of Cu, Zr, and Y compared to non-matrix standard solutions. The standard addition method, however, directly adds the standard substance to the sample solution, ensuring that the standard working solution and the sample solution have a completely identical matrix composition. This effectively cancels out the influence of the matrix effect on the standard curve and sample determination, significantly improving quantitative accuracy. The standard stock solution was diluted to three concentration gradients of 200 ng / L, 500 ng / L, and 1000 ng / L, covering the typical content range (ppt to ppb level) of trace metal impurities in electronic-grade titanium precursors. The grouping of standard solutions 1 and 2 considers the potential chemical incompatibilities (such as co-precipitation or complexation competition) between some elements (e.g., Ti and Zr) in multi-element mixed standard solutions, avoiding the impact of the stability issues of the standard substance itself on calibration accuracy.

[0037] In some embodiments, when detecting Cu, Zr, and Y impurities in Star-Ti, the regression equation established by S3 is as follows: Selecting the [63->97] Cu and NH3 modes for Cu detection, the regression equation is y=7.3534. x+27.78, correlation coefficient R 2 =0.9995; Selecting the [89->105]Y and O2 modes to detect Y, the regression equation is y=42.1811. x+316.67, correlation coefficient R 2 =0.9988; Zr was detected using the [90->106] Zr and O2 modes, with a regression equation of y=147.3687. x+148.8867, correlation coefficient R 2 =0.9993.

[0038] By employing the above technical solutions, the linear correlation coefficients of the regression equations established for Cu, Zr, and Y impurities in Star-Ti all reached above 0.9988, indicating a good linear quantitative relationship between the mass spectrometric response of ICP-MS / MS and the elemental concentration within the concentration range of 200–1000 ng / L. Specifically, Cu was selected using the NH3 mode with mass number transfer [63→97], while Zr and Y were selected using the O2 mode with mass number transfer [90→106] and [89→105], respectively. This selection was based on the differentiated selection of mass spectrometric interference types and the chemical behavior of the reactant gases for each element. + (m / z 63) in titanium matrix subjected to 47 Ti 16O + , 46 Ti 16 O 1 H + Interference from polyatomic ions, NH3, as a reactant gas, transfers Cu through a proton transfer reaction. + Transfer to m / z 97 (Cu(NH3)2) + Interfering ions, due to their difference in reactivity, are not transferred, thus achieving selective separation; Zr + (m / z 90) and Y + (m / z 89) is then affected 50 T 40 Ar+、 49 Ti 40 Ar + Argon-based polyatomic ion interference; O2, as the reactant gas, transfers the analyte ions to MO via charge transfer / addition reactions. + Product ions (m / z 106 and 105), while TiAr + Interfering ions, due to bond energy differences, do not react effectively with O2 and are therefore excluded by the mass filter. The three elements employ different reaction modes and mass transfer pathways, demonstrating the core innovation of the ICP-MS / MS classification reaction gas mass transfer strategy. Coordinated optimization of various parameters ensures the selectivity and sensitivity of interference elimination.

[0039] In some embodiments, in step S4, when detecting Zr and Y metal impurities in the sample solution, the O2 mode is used, selecting [89->105]Y and [90->106]Zr, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.5kW, plasma gas flow rate 15.0 L / min, oxygen flow rate 30%, extraction lens 1 voltage 4.0V, compensation gas flow rate 0.48L / min, nebulizing gas flow rate 0.7L / min, energy discrimination voltage -7.0V, sampling depth 9.0mm, extraction lens 2 voltage -110V, nebulization chamber temperature 2.0℃, octet deflection voltage -3.0V, axial acceleration voltage 1.5V.

[0040] By adopting the above technical solution, the detection of Zr and Y uses the O2 reaction mode and selects the mass number transfer paths [89→105]Y and [90→106]Zr. An oxygen flow rate of 30% is the core parameter of the O2 mode; at this flow rate, O2 molecules react with Y... + Zr + The reaction efficiency reaches its optimal level, and the product ion YO + ZrO + It achieves high yield and few side reactions, while avoiding the reaction of excess O2 with the titanium matrix to form TiO. +New interfering ions are detected. The differential setting of extraction lens 1 voltage (4.0V) and extraction lens 2 voltage (-110V) enables efficient extraction and focusing of product ions; the energy discrimination voltage (-7.0V) effectively filters low-kinetic-energy interfering ions and neutral particles; the octupole deflection voltage (-3.0V) and axial acceleration voltage (1.5V) work synergistically to optimize the transport efficiency and collision focusing effect of product ions in the octupole collision / reaction cell. A sampling depth of 9.0mm effectively deflects the ion beam from the plasma center region to the mass analyzer, reducing the introduction of matrix ions into the edge regions.

[0041] In some embodiments, in step S4, when detecting Cu metal impurities in the sample solution, the NH3 mode is used, [63->97]Cu is selected, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.5kW, plasma gas flow rate 15.0 L / min, helium flow rate 1.0 L / min, extraction lens 1 voltage 4.0V, compensation gas flow rate 0.38L / min, nebulizing gas flow rate 0.7L / min, energy discrimination voltage -8.0V, sampling depth 9.0mm, ammonia flow rate 65%, extraction lens 2 voltage -250V, nebulization chamber temperature 2.0℃, octet deflection voltage -5.0V, axial acceleration voltage 0.5V.

[0042] By adopting the above technical solutions, unlike the O2 mode of Zr / Y, the NH3 mode involves a more complex cluster reaction, Cu + It undergoes stepwise addition with NH3 molecules to form Cu(NH3). + Cu(NH3)2 + Equivalent product ions were ultimately selected, with m / z 97 (Cu(NH3)2). + , 63 Cu(NH3)2 + () is used as the quality number for testing.

[0043] In some embodiments, the sample preparation and testing process is carried out in a cleanroom environment with at least Class 1000 and Class 100 cleanroom facilities. Only in a clean environment can the accuracy of the test results be ensured.

[0044] Example Example 1: A method for detecting the content of metal elements in electronic-grade titanium precursors, comprising the following steps: S1. Pretreatment of titanium precursor: Take three parallel portions of the titanium precursor Star-Ti to be tested and add them to polytetrafluoroethylene screw-top bottles. Each sample is 30 mg. Place them on the workbench of the clean room and add 1 mL of 18.2 MΩ•cm ultrapure water, 2 mL of ultrapure hydrogen peroxide, 3 mL of ultrapure concentrated nitric acid, and 2 mL of ultrapure concentrated hydrofluoric acid in sequence. Digest at 180℃ to form a clear acidic solution. Then dilute the above acidic solution to 50 mL with 18.2 MΩ•cm ultrapure water and disperse evenly to obtain the sample solution. The blank solution is also diluted under the same conditions to be tested.

[0045] S2. Prepare standard working solution: Standard solutions 1 and 2 were prepared using a 2 wt% nitric acid solution, wherein: Standard solution 1 contains the following elements: Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, Re, Sc, Se, Sm, Sr, Tb, Th, Tl, Tm, U, V, Y, Yb, and Zn, with a concentration of 10 mg / L.

[0046] Standard solution 2 contains the elements Ag, Ge, Hf, Mo, Nb, Sb, Si, Sn, Ta, Te, Ti, W, and Zr, with a concentration of 10 mg / L. Standard solutions 1 and 2 were diluted with 18.2 MΩ•cm ultrapure water to prepare standard stock solutions 1 and 2, each with an elemental concentration of 100 μg / L.

[0047] Using the standard addition method, standard stock solution 1 and standard stock solution 2 were added to the sample solution to obtain standard working solution 1 with an element concentration of 200 ng / L, standard working solution 2 with an element concentration of 500 ng / L, and standard working solution 3 with an element concentration of 1000 ng / L.

[0048] S3. Draw the standard curve: The standard working solutions 1-3 were tested using an ICP-MS / MS instrument to obtain the standard curve and regression equation.

[0049] The ICP-MS / MS test parameters are as follows: The ICP-MS / MS instrument used was an Agilent 8900, with a peak type of 1-point acquisition, a repetition count of 3, and a scan / repetition count of 10.

[0050] When testing for Zr and Y metallic impurities in the sample, the O2 mode was used, with [89->105]Y and [90->106]Zr selected. The scan type was cascaded, and the instrument parameters are shown in Table 1. Table 1

[0051] When testing for Cu metal impurities in the sample, the NH3 mode was used, [63->97]Cu was selected, the scan type was cascaded, and the instrument parameters are shown in Table 2: Table 2

[0052] A regression equation was established based on concentration and signal value, as shown in Table 3 below, where y represents the response signal value of the ICP-MS / MS instrument, and x represents the element concentration (ppt): Table 3

[0053] S4. Sample solution detection: The sample solution was tested using an ICP-MS / MS instrument, and the contents of copper, zirconium and yttrium in the titanium precursor were calculated based on the regression equation.

[0054] The instrument detection limit and background equivalent concentration of metal impurities in this method are shown in Table 4. Table 4

[0055] Comparative Example Comparative Example 1, a method for detecting the metal element content in an electronic-grade titanium precursor, differs from Example 1 in that the pretreatment in S1 does not use 18.2 MΩ•cm ultrapure water and hydrogen peroxide. The Star-Ti sample is digested at 180°C, and only 3 mL of ultrapure concentrated nitric acid and 2 mL of ultrapure hydrofluoric acid are added. The sample surface has an oily substance and the bottom has a white solid. The acidic solution from the previous step is then diluted to 50 mL with 18.2 MΩ•cm ultrapure water, but a transparent, clear, and uniformly dispersed solution cannot be obtained.

[0056] Comparative Example 2, a method for detecting the metal element content in an electronic-grade titanium precursor, differs from Example 2 in that it uses ICP-MS / MS in He mode to test the same Star-Ti sample as in Example 1. The testing and processing methods are basically the same, the difference being the testing mode. The He mode parameters are shown in Table 5. Table 5

[0057] The instrument detection limit and background equivalent concentration of metal impurities in this method are shown in Table 6. Table 6

[0058] As can be seen from Comparative Example 2, the instrument detection limits and background equivalent concentrations of Cu, Zr, and Y elements tested in He mode are much higher than those in Example 1, showing a significant improvement when using the testing method in Example 1.

[0059] Comparative Example 3, a method for detecting the metal element content in an electronic-grade titanium precursor, differs from Example 1 in that the pretreatment involves adding 18.2 MΩ•cm ultrapure water, 3 mL of ultrapure concentrated nitric acid, and 2 mL of ultrapure hydrofluoric acid, followed by digestion of the Star-Ti sample at 180°C. The sample solution contained bubbles. Further dilution of the acidic solution to 50 mL with 18.2 MΩ•cm ultrapure water did not yield a transparent, clear, and uniformly dispersed solution. During ICP-MS / MS testing, the injection was discontinuous, and the test signal value was unstable.

[0060] Comparative Example 4, a method for detecting the metal element content in an electronic-grade titanium precursor, differs from Example 1 in that the pretreatment involves adding 1 mL of 18.2 MΩ•cm ultrapure water, 3 mL of ultrapure hydrogen peroxide, 3 mL of ultrapure nitric acid, and 2 mL of ultrapure hydrochloric acid, followed by digestion of the Star-Ti sample at 180°C. The sample solution contains bubbles. The acidic solution from the previous step is then diluted to 50 mL with 18.2 MΩ•cm ultrapure water, but a transparent, clear, and uniformly dispersed solution cannot be obtained.

[0061] Performance verification of the testing method: After processing Star-Ti samples according to Example 1, the metal impurity content in the samples was tested using the corresponding methods to verify the repeatability, reproducibility, linearity, and recovery rate of the method. The standard curve reflects the linear quantitative relationship between different concentrations of the analyte and the instrument response value. The correlation coefficient R of the calibration curves for each analyte is [missing information]. 2 The value should satisfy R 2 ≥0.995. Repeatability and reproducibility, measured under controlled conditions, reflect the magnitude of errors in the measurement system and are expressed as relative standard deviation (RSD). Repeatability RSD should be ≤10%, and reproducibility RSD should be ≤10%. Recovery is typically used to evaluate the accuracy and reliability of the method, with standards requiring a recovery rate between 80% and 120%. The table below shows the repeatability, reproducibility, linearity, and recovery rates of the Star-Ti validation method. The data indicate that repeatability, reproducibility, linearity, and recovery rates all meet the standard requirements.

[0062] The method validation results are shown in Table 7: Table 7

[0063] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for detecting the content of metallic elements in electronic-grade titanium precursors, characterized in that, Includes the following steps: S1. Titanium precursor treatment: Add the titanium precursor to be tested into a container, add water, oxidant and inorganic acid in sequence, digest into a clear acidic solution, dilute and disperse the clear acidic solution evenly to obtain the sample solution. S2. Prepare standard working solutions by adding copper, zirconium, and yttrium standards to the sample solution using the standard addition method. S3. Plot the standard curve. Use an ICP-MS / MS testing instrument to detect the standard working solution and plot the standard curve and regression equation. S4. Sample solution detection: The sample solution was detected using an ICP-MS / MS instrument, and the contents of copper, zirconium, and yttrium in the titanium precursor were obtained according to the regression equation.

2. The detection method according to claim 1, characterized in that, In step S1, the titanium precursor includes at least one of titanium tetrachloride, tetra(dimethylamino)titanium, and trimethoxy(pentamethylcyclopentadienyl)titanium.

3. The detection method according to claim 1, characterized in that, The final concentration of the titanium precursor in the sample solution was 0.5–0.75 mg / mL.

4. The detection method according to claim 1, characterized in that, In step S1, the water is ultrapure water with a purity of 18.2 MΩ•cm; The oxidant is hydrogen peroxide; The inorganic acid is nitric acid and hydrofluoric acid in a volume ratio of 3:

2.

5. The detection method according to claim 4, characterized in that, The ratio of water, oxidant, and inorganic acid used is 1 mL: 2 mL: 5 mL.

6. The detection method according to claim 1, characterized in that, In step S1, after the digestion treatment, the clear acidic solution is diluted with ultrapure water to a final volume of 40-60 mL to obtain a clear sample solution.

7. The detection method according to claim 1, characterized in that, In step S1, the digestion temperature is 150–200°C.

8. The detection method according to claim 1, characterized in that, In step S2, the preparation of the standard working solution specifically includes the following: Prepare standard solutions of Y, Zr, and Cu, each with a concentration of 10 mg / L; The standard solution was diluted with 18.2 MΩ•cm ultrapure water to prepare standard stock solutions with an elemental concentration of 100 μg / L. The standard stock solutions were added to the sample solutions using the standard addition method to obtain standard working solution 1 with an elemental concentration of 200 ng / L, standard working solution 2 with an elemental concentration of 500 ng / L, and standard working solution 3 with an elemental concentration of 1000 ng / L.

9. The detection method according to claim 1, characterized in that, In step S4, when detecting Zr and Y metal impurities in the sample solution, the O2 mode is used, selecting [89->105]Y and [90->106]Zr or [92->108]Zr, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.4~1.5kW, plasma gas flow rate 10.0~15.0L / min, oxygen flow rate 20%~30%, extraction lens 1 voltage 3.0~4.0V, compensation gas flow rate 0.40~0.48L / min, nebulizing gas flow rate 0.6~0.7L / min, energy discrimination voltage -8.0~-7.0V, sampling depth 8~9.0mm, extraction lens 2 voltage -110V, nebulization chamber temperature 2.0±0.5℃, octet deflection voltage -4.0~-3.0V, axial acceleration voltage 1.0~1.5V.

10. The detection method according to claim 1, characterized in that, In step S4, when detecting Cu metal impurities in the sample solution, the NH3 mode is used, selecting [63->97]Cu or [65->99]Cu, and the scan type is cascaded; the instrument parameters are set as follows: Radio frequency power 1.4–1.5 kW, plasma gas flow rate 10.0–15.0 L / min, helium flow rate 0.8–1.0 L / min, extraction lens 1 voltage 3.0–4.0 V, compensation gas flow rate 0.35–0.38 L / min, nebulizing gas flow rate 0.6–0.7 L / min, energy discrimination voltage -10–-8.0 V, sampling depth 8–9.0 mm, ammonia flow rate 60%–65%, extraction lens 2 voltage -250 V, nebulization chamber temperature 2.0 ± 0.5 °C, octet deflection voltage -0.6–-5.0 V, axial acceleration voltage 0.4–0.5 V.

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