JPH0316901A - Production of metal halide - Google Patents

Abstract

PURPOSE:To inexpensively and efficiently obtain the desired metal halide by adding a halogen-containing compound to a system of gaseous organometallic compound having a specific concentration or above and irradiating a part of the system with energy beams having density not less than a specific density. CONSTITUTION:A gaseous halogen-containing compound is added to a system of gaseous organometallic compound causing exothermic decomposition reaction and having concentration of >=10<15> molecule per ml and a part of the system is irradiated with energy beam having energy density of >=10<-4> joule per cm<2> to afford an active seed originated in the above-mentioned organometallic compound and having high concentration in a part of the system and then exothermic chain reaction of the organometallic compound with the halogen-containing compound is brought out by the active seed to provide the metal halide. As the organometallic compound, every organometallic compound becoming as and causing exothermic reaction when decomposed into a metal atom may be used and is not especially limited to the use. As the halogen-containing compound, methyl chloride, methyl fluoride, methyl bromide, methyl iodide, F2, Cl2, Br2, I2, etc., are preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel method for producing metal halides. More specifically, the present invention relates to a method for producing 4 metal halides, which are useful as electronic materials, from organic metal compound vapor at low cost and extremely efficiently using energy rays such as laser light. be.

[Prior Art] Conventionally, metal halides have been widely used as, for example, electronic materials because they have various properties.

A known method for producing such halides is, for example, to refine the metal and then bring it into contact with halogen gas at high temperature, but such a method requires the input of a large amount of energy such as heat. However, there were problems in terms of energy conservation as well as high manufacturing costs.

On the other hand, there is a known method of producing fine metal particles by decomposing the vapor of a metal compound.
A method of decomposing organometallic compounds using laser light [Chem.
d Ind,) Volume 15, Page 247 (198
5 years) Ko etc. are known.

However, in the case of conventional methods for decomposing vapors of metal compounds, for example, in the case of laser light, at least one photon of energy is required to decompose one molecule of metal fine particles, and a large amount of expensive laser light is required. It requires energy, it is difficult to control the reaction, and there are problems such as by-products and how to use it, so it is disadvantageous economically and in terms of quality.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a method for manufacturing metal halides from vapor of metal compounds at low cost and extremely efficiently using energy sources such as laser light. It's a terrible thing to do.

[Means for Solving the Problem] The present inventors have previously conducted extensive research on a method for obtaining high-purity metal particles from the vapor of a metal compound. If you irradiate the energy beams above, it will be extremely energy efficient.
, discovered that fine metal particles could be obtained economically,
Furthermore, in the system of a gaseous organometallic compound having a specific concentration or more, another gaseous metal compound having a different metal classification from that of the organometallic compound is made to exist, and this is charged with an energy having a specific energy density or more. It has been discovered that composite metal compounds can be obtained with extremely high energy efficiency and economic advantage by irradiation with radiation.

As a result of further intensive research, the present inventors discovered that a halogen-containing compound was contained in the system of a gaseous organometallic compound at a specific concentration or higher, and this was combined with energy rays at a specific energy density or higher, such as laser beams. By irradiating a single pulse of light, a desired metal halide can be produced inexpensively and extremely efficiently with a small amount of input energy, and the composition and amount of the halide can be easily controlled. Based on this finding, we have completed the present invention.

That is, in the present invention, a gaseous halogen-containing compound is present in a system of an organometallic compound that causes a gaseous exothermic decomposition reaction at a concentration of 1015 molecules or more per ml. 10” per cm2
'By irradiating an energy beam with an energy density of Joule or more, a high concentration of active species caused by the organometallic compound is generated in a part of the system, and then the organometallic compound and halogen-containing compound caused by this active species are The present invention provides a method for producing a metal halide, which is characterized by producing a metal halide by an exothermic chain reaction with a metal halide.

The present invention will be explained in detail below.

The organometallic compound used in the method of the present invention is not particularly limited as long as it becomes gaseous and causes an exothermic reaction when decomposed into metal atoms. Examples of such organometallic compounds include tetraalkyl lead, trialkyl bismuth, trialkyl thallium, dialkyl zinc, dialkyl mercury, and dialkyl cadmium.

Here, the alkyl group includes methyl group, ethyl group, n-
Examples include probyl group and inglovir group, and they may be linear or branched.

The organometallic compound of the present invention must undergo an exothermic reaction when decomposed into metal atoms.

As a typical example of an organometallated metal compound, general 2 MI R 1 (M1: metal, R1: alkyl group, n: number of alkyl groups, usually an integer of 1 to 4) is used. Suppose that the reaction is expressed as the formula M'R', +M'+ (n/2) R'-R'. Here, the bond dissociation energy in the reaction formula represented by the formula M'R', -+M'+n R' is DA, and the radical in the reaction formula represented by the formula n R'+ (n/2)R'-R' If the recombination A and R of R1 are DB, then ΔH=DA DB.

If ΔH becomes negative, an exothermic reaction will occur.

By using such an organometallic compound, a chain reaction due to 5-101 heat proceeds, and the object of the present invention can be achieved. In order to smoothly start and proceed the chain decomposition reaction, it is preferable to use a material with a relatively high vapor pressure that can increase the raw material concentration. For example, an organometallic compound having a small number of carbon atoms in an alkyl group is preferable.

Further, the larger the absolute value of ΔH of the organometallic compound is, the more preferable it is, and as such an organometallic compound, tetramethyl lead (ΔH = −25 kcall/man)
, trimethyl bismuth (ΔH=-30k.ca/m
o L ), etc.

On the other hand, as a halogen-containing compound, halogen element (F
, CQ, Br, ■) and becomes gaseous. There is no particular restriction, but a compound that has a high vapor pressure and is easily decomposed is desirable. Among such compounds are methyl fluoride, methyl chloride, methyl bromide, methyl iodide, as well as F,, CIl2, Br. , ■, etc. are suitable. One type of these halogen-containing compounds may be used, or two or more types may be used in combination.

When the organometallic compound and the i-containing compound as described above are present, and a part of this system is irradiated with energy rays such as the laser described below, an exothermic chain reaction proceeds, and the metal ＼Rogenide can be avoided.

The chain reaction here is mainly a decomposition reaction and a nitrogenation reaction. Furthermore, "exothermic" means that the total heat balance in the reaction is negative.

The specific explanation is as follows.

As an organometallic compound, for example, the general formula, MI R *, (
M2: metal, R2, alkyl group, m: positive rational number) and a compound represented by the general formula, R3, , X is a halogen atom, p is O or a positive rational number, and q is a positive rational number) in a molar ratio of 1:y (y is a positive rational number). The reaction is M ''R 2,10y R 3,X (+[ M2-x
+ F ] + [ R2− + R” e v (
or R ``m-R ''ey)]... is represented by Formula I.

7 81? Here, R2■ is the most stable alkane compound generated by the recombination reaction of R2 radicals of m molecules generated by the decomposition reaction, and R''eW is the y mole of the nitrogen-containing compound R.
',X. It is the most stable compound generated from the R3i child of the pyW child or the R3 molecule of the py molecule.

Furthermore, R2-RZv is the most stable compound produced by the reaction between the R2 radical of m molecules and the R3 atom of a py atom or the R3 molecule of a py molecule.

In this reaction, when DA+Dll-DC-DD<O, an exothermic reaction occurs, and the heat promotes a chain reaction to produce metal/% halogenide M"-X., where DA is M2 R2 , is the bond dissociation energy that decomposes into M 2+ m R'', D, is R'', and X. is p
It is y times the bond dissociation energy that decomposes into R3+QX, and DC is y times the bond dissociation energy that decomposes into R3+QX. , the bond energy that produces R2, which is the most stable alkane compound from DBI:tmR', and R' p, which is the most stable compound from pyR'.
It is the sum of the bond energies that produce y.

However, when Rζ-R3,, occurs in formula I, DD is R2,-R from m R2 and pyR'.
``This is the binding energy that produces ty.

In the method of the present invention, the vapor concentration of the organometallic compound in the system is 10 lfi molecules/ml (approximately I Tor at room temperature).
r) or more, preferably 10" molecules/mQ or more, more preferably 1017 molecules/ml or more. If this concentration is lower than 7 mlb of 101s molecules, the concentration of the active species for chain initiation is too low. During the lifetime of the active species, a reaction with the halogen-containing compound occurs and the active species are deactivated, making it difficult to initiate a chain reaction.

Appropriate conditions can be selected for the vapor concentration of the organometallic compound in relation to the energy absorption coefficient of the organometallic compound. For example, when the frequency of the energy beam is selected and irradiation is performed under conditions that provide high absorption efficiency, the chain decomposition reaction will start even if the vapor concentration is reduced.

On the other hand, the concentration of the halogen-containing compound in the system -9 10 is not particularly limited, but is preferably at most 4 times the molar concentration of the organometallic compound.

In the method of the present invention, a diluent gas may be present in the system as desired. Examples of diluent gas include helium,
Nitrogen, hydrogen, argon, etc. can be used.

The concentration of this diluent gas is appropriately selected depending on the intensity of the energy rays to be irradiated, but is preferably lower in order to cause a chain decomposition reaction.

In the method of the present invention, there are no particular limitations on the energy rays used for the chain initiation reaction as long as they can generate active species at a high density. Such energy rays include, for example, laser light, incoherent light such as mercury lamps and xenon lamps, orbital synchrotron radiation, electromagnetic waves such as microwaves and radiation such as X-rays, ion beams, electron beams, plasma, etc. Among these, laser light, orbital synchrotron radiation, and X-rays are preferred, and laser light is particularly preferred.

This laser light is preferably from a high-output pulse laser, and specifically, excimer lasers that oscillate in the ultraviolet region, nitrogen lasers, carbon dioxide lasers that oscillate in the infrared region, carbon monoxide lasers, YAG lasers, glass lasers, etc. Lasers include ruby lasers, alexandrite lasers, harmonics of YAG lasers that oscillate in the visible region, copper vapor lasers, gold vapor lasers, dye lasers, argon ion lasers, krypton ion lasers, and the like.

Generally, organometallic compounds have large absorption in the ultraviolet region, and therefore, among the lasers described above, when a laser that oscillates in the ultraviolet region is used, active species can be easily generated at a high density. Excimer lasers are particularly suitable because they have such an effect and a high energy density. Further, a carbon dioxide laser is also preferable because it can lead to decomposition by multiphoton excitation of the vibrational level that the organometallic compound has in the infrared region. Note that even if another laser is used to irradiate at a wavelength that has no excitation level, it is generally possible to cause breakdown by the laser, and therefore chain decomposition can be caused.

The energy beam in the present invention may be a continuous energy beam, but a pulsed beam is preferred because it can easily generate active species with high density.

The higher the energy density of energy ray irradiation in the present invention, the more advantageous it is.

In the present invention, it is preferable to closely adjust the irradiation time to maintain a high concentration of active species generated per unit time.
This is preferably within 10-3 seconds, particularly preferably within 10-' seconds, and even more preferably within 10-6 seconds. Even if the irradiation time is made longer than this value, the active species will be deactivated, so it may not be possible to increase the concentration of the active species.

Further, in this case, the energy density of the irradiation rays should be at least 10 -4 joules, preferably at least 10 -3 joules per cm 2 , and chain decomposition reactions will hardly start if the density is lower than this.

Moreover, it is desirable that the irradiation with this energy ray be carried out under conditions where the absorption coefficient (molar absorption coefficient when the energy ray is light such as a laser beam) of the metal compound to be irradiated is large. For example, when a tetramethyl vessel is used as a raw material, the absorption coefficient has a maximum value around a wavelength of about 200 nm, and in this case, it is preferable to use an ArF excimer laser with a wavelength of 193 nm.

By irradiating such energy rays, a part of the system is exposed to x011 cells/mL or more, preferably 1016 cells/mL.
．． These high concentrations of active species are generated, and an exothermic chain reaction caused by the active species occurs sequentially, causing the organometallic compound to almost completely decompose in an instant, and the metal active species to react with the halogen. , fine particles of metal halide are produced.

Further, in the present invention, other metal compounds may be present in addition to the organometallic compound as long as the object of the present invention is not impaired. Such a metal compound is not particularly limited as long as it becomes gaseous. Examples of the other metal compounds include lead, bismuth, thallium, zinc, aluminum, cadmium, mercury, gold, silver, platinum, cobalt, nickel, iron,
Organometallic compounds having a metal-carbon bond between an alkyl group of a metal or metalloid such as tin, silicon, germanium, etc., and hydrides, alkoxides, carbonylates, metallocene compounds, halides of these metals or metalloids, Examples include hydroxides, oxides, carbides, nitrides, sulfides, etc., and one type of these metal compounds may be used,
You may use two or more types in combination.

As in the case of the organometallic compounds, these metal compounds are preferably those whose decomposition reaction is exothermic, those whose bond dissociation energy is small, and those whose vapor pressure is relatively high. In addition to the organometallic compounds such as tetramethyl lead, trimethyl bismuth, and trimethyl thallium, metal halides are preferable because of their high vapor pressure, and metal carbonyl compounds such as iron carbonyl and nickel metal compounds are preferable as such compounds. Luponyl, chromium carbonyl, molybdenum carbonyl, tungsten carbonyl, and the like are preferred because they have low bond dissociation energy for decomposition into metal atoms. If other metal compounds are used in this way,
A metal halide consisting of multiple metals is obtained.

The diameter of the metal halide fine particles thus obtained is 1 μm or less, but most of the particles are 0.3 μm or less.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

Example 1 In a 7 ml quartz cell, 3.3 x 10'' molecules/mA (10.OT o r r) of tetramethyl lead was sealed, and 6.4 x 10'' molecules/mA of methyl iodide was sealed therein.
! (1,9.3 Torr) was added. Laser light from a KrF excimer laser with sufficient photon density for this sample (wavelength: 248 nm, energy density: 7 5
mJ/cm2) for 1 pulse (IXIO-a seconds)
When irradiated, a chain decomposition reaction occurred all at once while emitting orange light, and after the reaction approximately 1.7 mg of yellow fine particles of lead iodide with a particle size of -15--16-0.3 μm or less were produced.
was generated.

When this product was analyzed by X-ray photoelectron spectroscopy (XPS), the iodine peak was found at 619.1e.
It appeared near V, and a lead peak was observed at 138.5 eV. On the other hand, the standard sample (Nyokasen) had 6 1 9. O eV and 13B. A peak was observed at 4 eV. The lead peak of PbI, is also similar to that of W. B. Mo
The value reported by rgan et al. 1 38.
5eV (J.Phys.Cham.77,96,'7
3) shows good agreement. Based on this measurement result, the presence of a living substance was confirmed.

Example 2 Tetramethyl lead 8.3 x 101 in a 7 mQ quartz cell
7 molecules/mQ (2 5.OT.o r r), and methyl bromide 2.6
．． 9 Torr) was added. Laser light from an ArF excimer laser with sufficient photon density for this sample (wavelength: 193 nm, energy density: 50 mJ/cm)
2) was irradiated with one pulse (IXIO-' seconds),
A chain decomposition reaction occurred all at once while emitting orange light, and after the reaction, about 2.8 mg of lead bromide fine particles with a particle size of 0.3 μm or less were produced.

When this raw material was subjected to XPS measurement, the value matched that of a commercially available sample (lead dibromide).

The product was confirmed from this measurement result.

Example 3 Tetramethyl lead 8.3×1 in a 7rrfL quartz cell
017 molecules/mA (25.OTorr) was added.

One pulse of laser light (wavelength 193 nm, energy density 50 mJ/cm2) from an ArF excimer laser with sufficient photon density was applied to this sample (1
When irradiated (0-' seconds), a chain reaction of decomposition and production occurred at once while emitting orange light, and after the reaction the particle size was 0.3.
Approximately 2.6 mg of lead chloride fine particles with a size of less than μm were administered.

When this product was subjected to XPS measurement, the value coincided with that of a commercially available sample (dichloride vessel). The product was confirmed from this measurement result.

17-18- Example 4 The same procedure as Example 2 was carried out except that trimethyl bismuth was used instead of tetramethyl lead in Example 1. A chain decomposition reaction occurred, and the particle size after the reaction decreased. Approximately 3.5+ fine particles of bismuth iodide of 0.3 μm or less
produced B.

Comparative Example 1 In Example 1, laser light irradiation was performed at an energy density of 7. 5 X 10-'J/cm2, irradiation intensity 0.
When carried out in the same manner as in Example 1 except that the test was carried out under the condition of 3 mJ, no chain decomposition reaction proceeded.

Comparative Example 2 In Example 1, the steam concentration in the tetramethyl ship was set to 3.3.
When carried out in the same manner as in Example 1 except that the setting was X10'' molecules/m0. (0.01 Torr), no chain explosive reaction was observed.

[Effects of the Invention] According to the method of the present invention, metal halides can be removed with a small input energy by irradiating a gaseous organometallic compound with one pulse of energy radiation in the presence of a gaseous halogen-containing compound. Therefore, it can be produced at a low cost and extremely efficiently. Moreover, since the halogenation reaction with the halogen occurs at the same time as the organometallic compound decomposes in the gas phase, the metal halide can be easily obtained, and the amount of halogen can be reduced. Since it is easy to control, it is easy to control the amount and composition of metal halides.

The metal halide obtained by the method of the present invention is suitably used, for example, as an electronic material.

Claims (1)

[Claims] 1. In a system of an organometallic compound that causes a gaseous exothermic decomposition reaction at a concentration of 10^1^5 molecules or more per ml,
A gaseous halogen-containing compound is present, and a part of the system is irradiated with an energy beam with an energy density of 10^-^4 joules or more per cm^2, so that a part of the system is exposed to the organometallic compound. production of a metal halide, characterized in that a high concentration of active species is generated, and then a metal halide is generated by an exothermic chain reaction between an organometallic compound and a halogen-containing compound caused by the active species. Method. 2. Claim 1, wherein the metal halide is in the form of fine particles.
Manufacturing method described.