JP2012132837A - Method and device for measuring impurity in organic metal compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rapid and inexpensive impurity measuring method and device for quantitatively determining impurities such as particles in a liquid material of an organic metal compound and measuring impurities in an organic metal compound in order to control quality.SOLUTION: An impurity measuring device comprises a turbidimeter 10, which has a sample cell 1 having a predetermined volume, a sample introduction part 1a for introducing a liquid material inside the sample cell 1, a sample supply part 1b for supplying the liquid material from the sample cell 1, a light source part 2 for irradiating the inside of the sample cell 1 with near-ultraviolet light, visible light and near-infrared light in a prescribed wavelength region and light receiving parts 3a and 3b for receiving transmitted light and/or scattered light from the sample cell 1. The impurity measuring device has a purge gas supply part for supplying a dry inert gas to purge the inside of the sample cell and calculates an impurity concentration in the liquid material from the turbidity detected.

Description

  The present invention relates to an impurity measurement method and an impurity measurement apparatus in an organometallic compound, for example, a measurement method and an impurity measurement of an impurity contained in an organometallic compound used in a production apparatus or research facility such as a semiconductor or a solar cell. It relates to the device. The “organometallic compound” referred to in the present application is an organic metal compound widely used industrially, for example, an organic zinc compound such as dimethylzinc (DMZn) or diethylzinc (DEZn), or an organic compound such as trimethylaluminum (TMA). An organic lithium compound such as an aluminum compound or normal butyl lithium (n-BuLi) can be given.

  Organic metal compounds such as those described above are often used as manufacturing devices for producing semiconductors, solar cells, etc., research facilities for developing new materials, or semiconductor materials that require high-purity products. While these organometallic compounds are used as high-purity liquid materials, there are many substances that are unstable to heat, air, or light, and exposure to them can cause deterioration such as oxidation, decomposition, and modification. There is. Along with such deterioration, impurities such as particles are often generated in the liquid material, and the particles have a great influence on manufacturing / research or product characteristics because they cause failure of semiconductor process equipment and film quality deterioration after film formation. May give. Therefore, it is necessary to remove and purify such impurities, and to establish a quick and inexpensive method for quantitatively determining impurities such as particles in the material and controlling the quality.

  In general, the quality of liquid materials for semiconductor manufacturing processes is guaranteed by assay (pure content), metal impurity content, and chlorine content. At this time, for analysis of assay, gas chromatography (GC) or proton nuclear magnetic resonance apparatus (1H-NMR), for analysis of metal impurities, inductively coupled plasma mass spectrometry (ICPMS), for analysis of chlorine component , Ion chromatography (IC) is used.

  For example, it is possible to purify organic zinc compounds that can be effectively purified to high purity by removing the halogen components mixed in the manufacturing process from crude products containing impurities such as DMZn, which are frequently used in semiconductor processes in recent years. Simultaneously with the method, a method for measuring the halogen concentration in the treated organozinc compound has been proposed (see Patent Document 1). Specifically, the reaction solution obtained by synthesizing the organozinc compound is simply distilled to remove the reaction solvent, the crude product of the obtained organozinc compound is brought into contact with activated carbon, and the mixed impurities are adsorbed and removed. In addition, the impurities in diethyl zinc include methyl iodide (MeI) and methyl chloride (MeCl), and a method using a gas chromatography spectrum and an emission spectrometer is proposed for the measurement ( (See Patent Document 1, paragraphs 0026 and 0027).

Japanese Patent Laid-Open No. 06-41151

However, the following methods and apparatus for measuring impurities in a liquid material of an organometallic compound as described above may cause the following various problems.
(I) The conventional methods for measuring impurities in liquid materials as described above cannot quantitatively detect the generation or discoloration of impurities such as particles due to self-decomposition.
(Ii) For example, when the assay is confirmed by “1H-NMR”, impurities cannot be detected unless the structure is soluble in the NMR solvent and has a proton in the molecule. It cannot be detected. Even if the impurity is a liquid in which a part of the molecular structure of the organometallic compound is changed, if the molecular structure is similar to that before decomposition, the separation of the NMR signal from the main component becomes insufficient, and the detection sensitivity is improved. descend.
(Iii) Metal analysis can detect metal impurities caused by contamination from the manufacturing process and filling process, but the impurities generated by self-decomposition are detected because they have the same metal element content as before decomposition. Can not.
(Iv) In the analysis of chlorine, as in the analysis of metals, chlorine-based impurities cannot be detected because they do not increase or decrease by self-decomposition.
(V) Further, in the method by gas chromatography, MeI and MeCl can be quantitatively analyzed as in the above example, but iodine and chlorine existing in other forms cannot be analyzed, and sensitivity is inferior. It is enough.
(Vi) As a method for measuring particles, measurement using a particle counter for liquids is known, but for measuring substances such as organometallic compounds that are unstable in the air, they are large and expensive to maintain airtightness. Equipment is necessary. In addition, it is necessary for the measurement to continuously introduce a certain amount of liquid material into the measuring apparatus, which is not preferable because a large amount of expensive liquid material is consumed.
(Vii) The method of evaporating and drying the liquid material and measuring the weight of the residue requires many liquid materials in order to collect measurable amounts of particles. In addition, when the liquid material is a metal compound, there is a method of measuring the metal component using the residue as an acid solution. This method requires a large measuring device such as ICPMS and ICPOES, and the measurement time is also long.

  An object of the present invention is to provide a quick and inexpensive method for measuring impurities in an organometallic compound and an impurity measuring device for quantitatively determining impurities such as particles in the liquid material of the organometallic compound and performing quality control. is there. In particular, highly sensitive and safe measurement of trace amounts of impurities in highly reactive liquid materials so that liquid materials for semiconductor processes requiring high purity can be supplied stably while maintaining high purity. An object of the present invention is to provide an impurity measuring method and an impurity measuring apparatus in an organometallic compound that can be performed.

  As a result of intensive studies in order to solve the above problems, the present inventors have found that the above object can be achieved by the following impurity measurement method and impurity measurement apparatus in an organometallic compound, and to complete the present invention. Arrived.

  The present invention relates to a method for measuring impurities in an organometallic compound, which is a specific wavelength region in which the liquid material in a sample cell of a turbidimeter having a predetermined capacity is irradiated with the liquid material of the organometallic compound as a measurement target. The concentration of impurities in the liquid material is measured by detecting the turbidity of the liquid material from the amount of absorption or / and scattering of near ultraviolet light to visible light to near infrared light.

  In a semiconductor manufacturing process or the like in which a liquid material of an organometallic compound having self-decomposability is used as a raw material or the like, a measurement method capable of selectively measuring impurities in the liquid material is required. In other words, in the originally purified organometallic compound, there are almost no impurities and it can be used as it is in the manufacturing process, but it is in the feeding process (including the storage process and heating process). In addition to being harmful in the manufacturing process, the particles produced by self-decomposition in are difficult to confirm their presence and their effects because the measurement method is unknown, and they can be removed or controlled. It was difficult. The present invention makes it possible to measure the concentration of particles generated by self-decomposition in a liquid material and scattered in the liquid material by utilizing the property that these particles absorb or scatter light and detecting it as turbidity. It has been found that. That is, particles generated by self-decomposition are the metal compounds of the original organometallic compound and have stable properties as a solid (and therefore become a problem in the manufacturing process), and therefore, liquid materials By utilizing the property of being dispersed while being separated into the liquid and using an index called turbidity of the liquid material, it has become possible to measure impurities such as particles with very high accuracy. Furthermore, by quantitatively determining such impurities such as particles, it has become possible to supply liquid materials for semiconductor processes that require high purity while stably maintaining high purity.

The present invention relates to a method for measuring impurities in the organometallic compound, which is one liquid material containing a predetermined concentration of impurities serving as a reference for the turbidity of the liquid material, or the impurity concentration produced and contained under the same conditions A calibration curve of the liquid material is created from the correlation between the turbidity detected in advance and the impurity concentration obtained from the residue obtained by transpiration / drying of the liquid material. In addition, the turbidity of the liquid material of an unknown organometallic compound is detected, and the impurity concentration of the liquid material is obtained from the detected turbidity based on the calibration curve.
In the measurement of impurities in the organometallic compound, it is preferable to treat and manage each process for substances whose sources such as raw materials are clear in the manufacturing process as described above. As described above, the present invention has found a method for measuring impurities that are self-decomposed particles, which are difficult to measure by conventional methods, and for which it is very difficult to specify the point of occurrence or the generation process. In order to obtain value traceability, it is necessary to clarify the criteria. In other words, particles generated by self-decomposition have the property of being stable as a solid, and have the property of being dispersed and dispersed in the liquid material, while the liquid material without impurities does not remain due to transpiration. , And by making the standard of impurities the residue after transpiration and drying of liquid material, and ensuring the quantitativeness, it is possible to obtain highly traceable measurement values with components that are problematic in actual processes I found. Specifically, impurities in organometallic compounds with very high measurement accuracy from the correlation between the turbidity detected in advance and the amount (concentration) of impurities obtained from the residue after transpiration / drying treatment It became possible to provide a measurement method.

The present invention is a method for measuring impurities in an organometallic compound,
The following primary processing processes:
(1) A liquid material of an organometallic compound containing a predetermined concentration of impurities is prepared in advance.
(2) The inside of the sample cell of the turbidimeter having a predetermined capacity is purged with a dry inert gas in advance.
(3) A predetermined amount of the liquid material prepared in (1) is introduced into the sample cell.
(4) The turbidity of the liquid material is detected.
(5) A predetermined amount of the liquid material is evaporated and dried, and the amount of impurities in the liquid material is obtained from the amount of the residue.
(6) The impurity concentration in the liquid material is calculated from the amount of impurities obtained in (5).
(7) A correlation between the turbidity obtained by (4) and the impurity concentration calculated by (6) is obtained.
And the following secondary processing process:
(8) A predetermined amount of a liquid material of an unknown organometallic compound is introduced into the sample cell.
(9) The turbidity of the liquid material is detected.
(10) The impurity concentration in the liquid material is calculated from the correlation obtained in (7) above.
It is characterized by having.
As described above, the present invention makes it possible to measure the concentration as an impurity by utilizing the unique properties of particles generated by self-decomposition of a self-decomposing organometallic compound. In other words, solid separation / dispersibility in liquid materials and liquid-solid separation by transpiration are quantified by different detection means, with the former as turbidity and the latter as the amount of residue, to clarify the correlation between the two. This makes it possible to measure impurities with extremely high accuracy. The present invention regards such a measurement method as two processing processes, and by clarifying each operation, it can be used in-line, and can be measured quickly, inexpensively, highly sensitively and safely for quality control. It is possible to provide an impurity measuring method and an impurity measuring apparatus in an organometallic compound that can be used.

The present invention relates to an apparatus for measuring impurities in an organometallic compound, which uses a liquid material of an organometallic compound as a measurement target, a sample cell having a predetermined capacity, and a sample introduction for introducing the liquid material into the sample cell A sample delivery unit for delivering the liquid material from the sample cell, a light source unit for irradiating near ultraviolet light to visible light to near infrared light in a specific wavelength region inside the sample cell, and the sample cell A turbidimeter having a light receiving portion for receiving transmitted light and / or scattered light, a purge gas supply portion for supplying a dry inert gas for purging the inside of the sample cell, and turbidity detected The impurity concentration in the liquid material is calculated from the degree.
As described above, it has been found that the measurement of impurities in an organometallic compound, which has been difficult in the past, can be performed with very high accuracy by using an index called turbidity of a liquid material. In addition, since the organometallic compound has self-decomposability and reacts with a small amount of moisture, oxygen, etc., and easily generates impurities, it is necessary to clean the inside of the sample cell constituting the turbidimeter with certainty. is there. The present invention proposes an apparatus for measuring impurities in an organometallic compound having a configuration capable of realizing such a demand.

The present invention also provides an apparatus for measuring impurities in the organometallic compound, comprising a housing for housing the turbidimeter, or a sealable space containing the sample cell, and a purge gas from the purge gas supply unit. Thus, the inside of the casing or the space portion forms an inert gas atmosphere.
In an apparatus for measuring impurities in an organometallic compound, it is important to purge the inside of the sample cell through which the organometallic compound flows, and it is preferable to shut off from the outside air. The present invention secures double safety by purging not only the sample cell, but also the space including this, and further the entire turbidimeter, and in particular the introduction of liquid material into the sample cell If there is a manual operation in the maintenance of the sample cell or the like, it functions very effectively in terms of preventing the generation of impurities from the measurement object.

Schematic which shows the example of 1 structure of the impurity measuring apparatus in the organometallic compound which concerns on this invention The figure which illustrates the verification result by the impurity measuring method in the organometallic compound concerning the present invention The figure which illustrates the verification result of the impurity measurement in the organometallic compound concerning the conventional method

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The method for measuring impurities in an organometallic compound according to the present invention (hereinafter referred to as “the present method”) and the impurity measuring device (hereinafter referred to as “the present device”) have a liquid material of the organometallic compound as a measurement object and have a predetermined capacity. Detecting the turbidity of the liquid material from the amount of absorption or / and scattering of near-ultraviolet light to visible light to near-infrared light in a specific wavelength range irradiated on the liquid material inside the sample cell of the turbidimeter To measure the concentration of impurities in the liquid material.

  The “liquid material” here is a liquid material containing particles or the like as impurities, and is intended for organometallic compounds, particularly organometallic compounds having self-decomposability. Generally, it refers to an organometallic compound that is liquid at normal temperature (20 to 30 ° C.) and normal pressure (about 0.1 MPa), but here also includes a solvent that is liquefied under a wide range of pressure conditions or predetermined temperature conditions. Specifically, as described above, organic zinc compounds such as DMZn and DEZn can be used.

<Outline of this device>
FIG. 1 is a schematic diagram showing a configuration example of the present apparatus. This apparatus has a predetermined capacity and irradiates the sample cell 1 into which the liquid material A to be measured is introduced and the near-ultraviolet light to visible light to near-infrared light in a specific wavelength region inside the sample cell 1. A turbidimeter 10 having a light source unit 2 and light receiving units 3a and 3b that receive transmitted light and scattered light from the sample cell is provided. The detected turbidity data is used by the computing unit 20 to calculate the impurity concentration in the liquid material from the turbidity. The computing unit 20 can use an external personal computer or the like, and can constitute a part of the turbidimeter 10. Connected to the sample cell 1 are a sample introduction part 1 a for introducing a liquid material into the sample cell 1 and a sample delivery part 1 b for delivering the liquid material from the sample cell 1. In addition, in this apparatus, although the structure which detects turbidity by both transmitted light and scattered light is illustrated, it is also possible to use the structure which detects only any one. Needless to say, the arrangement and necessity of installation of these components are not limited to the configuration shown in FIG.

  The apparatus preferably further includes a purge gas supply unit (not shown) for supplying a dry inert gas for purging the inside of the sample cell 1. Specifically, a purge gas supply path (not shown) is connected to the sample introduction part 1a or the sample supply part 1b, and a dry inert gas is supplied into the sample cell 1, thereby providing an inner wall part of the sample cell 1. Generation of impurities due to a reaction between adsorbed moisture and a highly reactive organometallic compound can be prevented. As the inert gas, a gas that has few impurities such as moisture and is easily available, such as nitrogen and argon, is preferable. The inert gas is introduced into the sample cell 1 through the inert gas introduction unit 4 at a predetermined supply flow rate set in advance. The introduced inert gas is sequentially fed to the flow path similar to the transfer of liquid material etc. (including liquid phase components etc.) such as the sample cell 1, so that the flow path and members in contact with the liquid material etc. Can be purged. At this time, the impurities adsorbed on the inner wall of the flow channel can be effectively purged by heating the flow channel and the member.

  In this apparatus, not only purging with an inert gas inside the sample cell 1 but also a housing (not shown) for storing the turbidimeter 10 or a sealable space (not shown) containing the sample cell 1 is provided. It is also possible to form an inert gas atmosphere inside the casing or the space by the purge gas from the purge gas supply unit. By shutting off from the outside air, double safety is ensured and safe manual operation is possible in maintenance of the sample cell.

[Measurement of impurity concentration]
This apparatus (this method) is characterized in that the impurity concentration in the organometallic compound can be measured from the turbidity in the liquid material. In other words, the calculation unit 20 converts the turbidity data stored in advance into the impurity concentration data from the correlation between the turbidity data and the impurity concentration data based on the input turbidity data. That is, such a function and a measuring method in this apparatus were found from the following knowledge obtained by examining the characteristics of the organometallic compound itself, the factors causing the impurities in the organometallic compound, and the characteristics of the impurities.
(I) The pure organometallic compound is completely evaporated by heating or the like, and no trace (residue) remains. Therefore, there is a possibility of extraction of impurities by transpiration treatment.
(Ii) The purified organometallic compound generates an impurity by autolysis, and the impurity is composed of the metal or a metal reaction product and a partially converted insoluble component of the metal compound. Therefore, it has a stable property as a solid, and remains as a residue without transpiration due to transpiration of the organometallic compound.
(Iii) The generated impurities form fine particles (particles) in the liquid material, and the impurities exist while being dispersed while being separated. Therefore, the liquid material containing impurities has light transmission properties or light scattering properties. Therefore, if this is detected as turbidity, quantitativeness can be ensured.

  This device (this method) uses the above findings (i) and (ii) and ensures the quantitativeness by measuring the residue of the transpiration / drying treatment of the liquid material as the standard of impurities. Can do. That is, in the case of a purified organometallic compound, the amount of residue (weight Wa) obtained by evaporating the organometallic compound out of the collected liquid material (weight Wo) can be used as the amount of impurities. From this, the impurity concentration Ca (= Wa / Wo) in the liquid material is calculated. In addition, from the knowledge (ii), it is possible to obtain high traceability between a component that becomes a problem in an actual process and the impurity serving as the reference. Furthermore, it can be derived from knowledge (iii) that there is a high traceability between the component in question and the component detected as turbidity. Specifically, as shown in the verification results of “turbidity and particles” in diethyl zinc described later and the verification in other organometallic compounds by the present inventor, it was found that both have a very good correlation. . Thus, for each organometallic compound, the correlation was previously stored in the calculation unit 20 as a calibration curve, and the turbidity was detected for the liquid material of the organometallic compound whose impurity concentration was unknown. From the turbidity data of the liquid material, the impurity concentration of the liquid material can be calculated using the calibration curve.

[Measurement of turbidity]
The light source unit 2 of the turbidimeter 10 uses a light emitting diode (LED) or a semiconductor laser that irradiates near ultraviolet light to visible light to near infrared light. The sample cell 1 is irradiated with high-density light by the optical lens 2a. At this time, the wavelength range of irradiation light with high selectivity is set depending on the type of the organometallic compound. The sample cell 1 is provided with a light-transmitting window (not shown) with respect to the light source unit 2 and the light receiving units 3a and 3b, and is made of a material that has no reactivity with the organometallic compound and has corrosion resistance. It is preferred that The temperature of the sample cell 1 is arbitrarily set depending on the characteristics of the liquid material to be processed and the processing content. For example, a temperature that can ensure temperature conditions necessary for preventing condensation of a low-boiling organometallic compound or preventing adsorption of a high-boiling organometallic compound is preferable. As the light receiving units 3a and 3b, photocells, photodiodes, phototubes, or the like are used, and turbidity data is created from each output.

  The light emitted from the light source unit 2 is condensed by the condenser lens 2a and irradiated to the sample cell. At this time, it is preferable to provide an optical filter (not shown) in order to increase the selectivity to the organometallic compound. The transmitted light absorbed by the impurities in the liquid material in the sample cell 1 reaches the light receiving unit 3a and is output as transmitted light data. The scattered light scattered by the impurities in the liquid material in the sample cell 1 reaches the light receiving unit 3b and is output as scattered light data. Turbidity is calculated from these data.

[Measurement of residue after transpiration and drying]
In this apparatus (this method), a predetermined amount of the liquid material is evaporated and dried, and the amount of impurities in the liquid material obtained from the residue amount is used as a reference. Specifically, a predetermined amount of a liquid material of an organometallic compound is collected in a heatable container, and the collected weight Wo is measured. Next, it heats as needed, performs a transpiration | evaporation and dry-solid process of a liquid material, and evaporates an organometallic compound to obtain a residue. In the case of a purified organometallic compound, the amount Wa of this residue can be the amount of impurities. Therefore, the impurity concentration Ca (= Wa / Wo) in the liquid material is calculated by measuring the amount Wa of the residue and setting it as the amount of impurities in the liquid material.

  At this time, the residue Wa can be measured by weighing the weight. In addition, since the residue contains a metal element, the residue is dissolved in an acid solution, and the amount of metal in the solution is analyzed using the above-described metal analyzer such as ICPMS or ICPOES. The measured value can be obtained. It is not a constant use for an unknown sample as described above, but a measurement for preparing a calibration curve for a specific organometallic compound, and does not become a large burden or problem as described above. The above operation is preferably performed in a sealed space purged with a dry inert gas because the organometallic compound has high reactivity.

<Measurement method of impurities in liquid material in this device>
In the present apparatus having the above configuration, impurities in the liquid material are measured along the following primary to secondary processing processes. Here, [1] primary processing in this method is a preliminary processing operation for preparing a calibration curve, and if a calibration curve for the same organometallic compound is stored, a new operation is omitted. Can do. [2] The secondary treatment process corresponds to measurement of impurities in a liquid material whose impurity concentration is unknown. The processing time of each process is set according to the internal volume of the sample cell 1 and other flow paths, the type of liquid material, and usage conditions.

[1] Primary treatment process This method has the following primary treatment processes.
(1) A liquid material of an organometallic compound containing a predetermined concentration of impurities is prepared in advance.
(2) The inside of the sample cell of the turbidimeter having a predetermined capacity is purged with a dry inert gas in advance. Specifically, an inert gas adjusted to a predetermined supply pressure in the inert gas supply unit is introduced into the sample cell 1 and supplied from the sample supply unit 1b. It is preferable to purge from the sample gas introduction part 1a provided in the upper part of the sample cell 1 to the sample delivery part 1b provided in the lower part. Further, the sample cell 1 is provided in a space (not shown) previously purged with a dry inert gas, and the following operations can be performed in an inert gas atmosphere.
(3) A predetermined amount of the liquid material prepared in (1) is introduced into the sample cell. Specifically, a predetermined amount of liquid material is introduced into the sample cell 1 via the sample introduction part 1a.
(4) The turbidity of the liquid material is detected. Specifically, the transmitted light absorbed by the impurities in the liquid material in the sample cell 1 reaches the light receiving unit 3a and is output as transmitted light data, and the scattered light scattered by the impurities reaches the light receiving unit 3b. Are output as scattered light data, and turbidity is calculated based on these data.

Next, it has the following processing processes.
(5) A predetermined amount of the liquid material is evaporated and dried, and the amount of impurities in the liquid material is obtained from the amount of the residue. Specifically, a predetermined amount (Wo) of the liquid material detected in the above (4) is collected, heated as necessary, transpiration / drying treatment of the liquid material, and transpiration of the organometallic compound. A residue is obtained. The amount Wa of this residue is measured and set as the amount of impurities in the liquid material. The amount Wa of the residue is measured by a gravimetric method or a metal analysis method as described above. In addition, it is preferable to perform such operation in the space sealed and purged to the same extent as said (2).
(6) The impurity concentration Ca (= Wa / Wo) in the liquid material is calculated from the collected weight Wo of the liquid material obtained in the above (5) and the impurity amount Wa.
(7) Correlation between the turbidity obtained by the above (4) and the impurity concentration calculated by the above (6) is obtained. Specifically, the calculation unit 20 calculates and stores a calibration curve approximated to a straight line or a quadratic curve as shown in FIG.

Moreover, this method has the following secondary processing processes.
(8) A predetermined amount of a liquid material of an unknown organometallic compound is introduced into the sample cell. Specifically, the same operation as the above (3) is performed on the liquid material.
(9) The turbidity of the liquid material is detected. Specifically, the same operation as the above (4) is performed on the liquid material.
(10) The impurity concentration in the liquid material is calculated from the correlation obtained in (7) above. Specifically, using the calibration curve calculated in (7) above, the impurity concentration in the corresponding liquid material is calculated from the turbidity detected in (9) above.

<Verification of measurement accuracy in this method and this device>
Using this device, diethyl zinc (DEZn) was used as a liquid material, and the measurement accuracy of this method and this device was verified.

(A) Verification of correlation (calibration curve) between turbidity and amount of residue (a-1) Measurement of turbidity About a sample of liquid material of diethyl zinc, a sample of a turbidimeter in an inert gas (N ₂ ) atmosphere It was introduced into the cell and the turbidity was measured. Turbidity is represented by polystyrene turbidity, which measures absorption and scattering light at a wavelength of 660 nm.
(A-2) Measurement of amount of residue Since particles in diethyl zinc are considered to be mainly composed of zinc, the content of particles is obtained by evaporating diethyl zinc to dryness (Zn particles) in an aqueous nitric acid solution. The amount of residue was measured by dissolving and analyzing the zinc concentration in the solution by ICPOES.
(A-3) Experimental Results FIG. 2 and Table 1 below show the results of measurement for three different samples (diethyl zinc). It was found that there is a correlation between turbidity and Zn particle amount, and the particle content can be determined by turbidity measurement. Specifically, a linear approximation correlation was obtained as shown in FIG.

(B) Verification using a conventional method (b-1) Verification conditions The same diethyl zinc as in the above (a) was analyzed using a conventional method, that is, 1H-NMR, ICPMS, ion chromatography (hereinafter, IC) (b -2) Verification results For particles in three different liquid samples (diethyl zinc), Fig. 3 shows the results of measurement using 1H-NMR, Table 2 below shows the results of measurement using ICPMS, 3 shows the results of measurement using an IC. Sample No. Although 1 to 3 had a significant difference in the particle content, it was clear that these differences could not be detected by these analysis methods.

DESCRIPTION OF SYMBOLS 1 Sample cell 1a Sample introduction part 1b Sample delivery part 2 Light source part 2a Condensing lens 3a, 3b Light-receiving part 10 Turbidimeter 20 Calculation part

Claims (5)

  Absorption amount of near-ultraviolet light to visible light to near-infrared light in a specific wavelength range irradiated on the liquid material inside a sample cell of a turbidimeter having a predetermined capacity, which is a liquid material of an organometallic compound, or A method for measuring impurities in an organometallic compound, wherein the concentration of impurities in the liquid material is measured by detecting the turbidity of the liquid material from the scattering amount. Turbidity detected in advance for one liquid material containing a predetermined concentration of impurities serving as a turbidity standard for the liquid material, or for a plurality of liquid materials prepared under the same conditions and having different impurity concentrations, From the correlation with the impurity concentration obtained from the residue obtained by evaporating and drying the liquid material, a calibration curve of the liquid material is created,
The turbidity of the liquid material of an unknown organometallic compound is detected, and the impurity concentration of the liquid material is obtained from the detected turbidity based on the calibration curve. Of measuring impurities in organometallic compounds. The following primary processing processes:
(1) A liquid material of an organometallic compound containing a predetermined concentration of impurities is prepared in advance.
(2) The inside of the sample cell of the turbidimeter having a predetermined capacity is purged with a dry inert gas in advance.
(3) A predetermined amount of the liquid material prepared in (1) is introduced into the sample cell.
(4) The turbidity of the liquid material is detected.
(5) A predetermined amount of the liquid material is evaporated and dried, and the amount of impurities in the liquid material is obtained from the amount of the residue.
(6) The impurity concentration in the liquid material is calculated from the amount of impurities obtained in (5).
(7) A correlation between the turbidity obtained by (4) and the impurity concentration calculated by (6) is obtained.
And the following secondary processing process:
(8) A predetermined amount of a liquid material of an unknown organometallic compound is introduced into the sample cell.
(9) The turbidity of the liquid material is detected.
(10) The impurity concentration in the liquid material is calculated from the correlation obtained in (7) above.
A method for measuring impurities in an organometallic compound, comprising:   A sample cell having a predetermined capacity, which is a liquid material of an organometallic compound, a sample introduction unit for introducing the liquid material into the sample cell, and a sample delivery unit for delivering the liquid material from the sample cell A light source unit that irradiates the inside of the sample cell with near ultraviolet light to visible light to near infrared light in a specific wavelength range, and a light receiving unit that receives transmitted light and / or scattered light from the sample cell. A purge gas supply unit for supplying a dry inert gas for purging the inside of the sample cell, and calculating an impurity concentration in the liquid material from the detected turbidity. For measuring impurities in organometallic compounds.   A housing for storing the turbidimeter or a sealable space containing the sample cell is provided, and an inert gas atmosphere is formed in the housing or the space by the purge gas from the purge gas supply unit. The apparatus for measuring impurities in an organometallic compound according to claim 4.