JPH02190408A - Manufacture of multi metal compound - Google Patents

Abstract

PURPOSE:To efficiently obtain a multi metal compound having high quality by irradiating gaseous metal compound having more than the specific concn. with energy ray having more than the specific density and generating active seed having high concn. CONSTITUTION:In a system of the organic metal compound (for example, tetramethyl lead, etc.) having concn. >=10<15> molecule/ml which gaseous exothermic decomposition reaction is generated, the gaseous metal compound (for example, trimethyl bismuth, etc.) having different metal component with the above is mingled. A part in this system is irradiated with the energy ray having >=10<-4> joule/cm<2> energy density to generate the active seed having high concn. of >= about 10<15>/ml. The exothermic chain reaction caused by this active seed is successively developed, and instantaneously organic metal compound and the other metal compound are almost perfectly decomposed, and reaction is generated among atoms to manufacture the fine particles of the multi metal compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel method for producing a composite metal compound. More specifically, the present invention aims to produce a high-quality composite metal compound composed of two or more metal elements useful as electronic materials etc. from the vapor of the metal compound at low cost using an energy source such as a laser beam. It concerns a highly efficient manufacturing method.

[Conventional technology]

In recent years, GaAs is composed of two or more elements.

Compound semiconductors represented by InP and SiC.

The characteristics of fine ceramics represented by SiN have begun to attract attention, and applied research on these compounds has been actively conducted.

These compounds are usually formed by mixing and decomposing two or more compounds containing the elements constituting the compound, or by decomposing a compound containing these elements in one molecule. For example, a gallium-arsenic compound semiconductor can be produced by decomposing a mixture of trimethylgallium and arsine. However, in the conventional method of decomposing such a mixture of two or more metal compounds, it is necessary to input a large amount of energy such as Reboux light, constant light, plasma, electron beam, heat, etc., and the manufacturing cost is high. In addition to being expensive, there were also problems in terms of energy conservation.

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 [[Chemistry and Industry (C
hem.

and Ind,) Volume 15, Page 247 (19
1985)] are known.

However, in the case of conventional methods for decomposing the vapor of metal compounds, for example, in the case of laser light, one molecule of metal fine particles is generated (this requires at least one photon of energy and requires a large amount of expensive laser light). It requires energy, is difficult to control the reaction, and has problems such as the production of by-products, so it is economically and qualitatively disadvantageous.

[Problems to be Solved by the Invention] The present invention is directed to producing a composite metal compound consisting of two or more metal elements from the vapor of the metal compound in a high-quality, inexpensive, and extremely efficient manner using an energy beam such as a laser beam. The purpose is to provide a method for manufacturing well.

[Means for Solving the Problems] The present inventors have previously conducted extensive research on a method for obtaining high-purity metal fine particles from the vapor of a metal compound, and have determined that a gaseous metal compound with a specific concentration or higher has a specific energy density. It has been found that metal fine particles can be obtained with extremely high energy efficiency and economically advantageous by irradiation with the above energy rays.

As a result of further research, the present inventors discovered that in the system of a gaseous organometallic compound at a specific concentration or higher, there was another gaseous metal compound having a different metal component from that of the organometallic compound. C1 By irradiating this with energy rays with a specific energy density or higher, high-quality composite metal compounds can be produced inexpensively and extremely efficiently with less input energy, and It was discovered that the composition can be easily controlled, and the present invention was completed based on this knowledge.

That is, the present invention provides a system of an organometallic compound that causes a gaseous exothermic decomposition reaction at a concentration of 1 O1s molecule or more per mQ, and another gaseous metal having a different metal component from that of the organometallic compound. A mixture of compounds is present, and a part of the system is irradiated with energy rays with an energy density of 10-4 dicol or more per cm2, so that a part of the system has a high concentration of activity due to the mixture. species and then by an exothermic chain reaction caused by this active species,
The present invention provides a method for producing a composite metal compound, which is characterized by producing a composite metal compound.

The present invention will be explained in detail below.

The organometallic compound used in the method of the present invention [hereinafter referred to as
The organometallic compound (A) 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 (A) include tetraalkyl vanes, trialkyl hismuth, trialkyl thallium, dialkyl zinc, dialkyl mercury, dialgylno J domium, and the like.

Here, the alkyl group includes medyl group, ethyl group, n-
Examples include propyl group and isopropyl 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 representative example of the organometallic compound (A), general 2M'
R'n, (MI, metal, Rl, alkyl group,
n: number of alkyl groups, usually an integer from 1 to 4) This reaction of MRn is 2 M'R'n-+M'+ (n/2)R'-
Suppose that it is expressed as R'. Here, the bond dissociation energy in the reaction formula expressed by the formula M'R' n + M ' 10n R' is DA, and in the reaction formula expressed by the formula nR'-"(n/2)R'-R' Letting the bonding energy of physical R1 be ΔH-DA-D.

If ΔH becomes negative, an exothermic reaction will occur.

By using such an organometallic compound (A),
A chain reaction due to 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.

Furthermore, the larger the absolute value of ΔH of the organometallic compound (A) is, the more preferable it is.
, trimethyl bismuth (ΔH!-36k aQ/m
ob) etc.

On the other hand, regarding the other metal compound (hereinafter referred to as "other metal compound (B)"), it is sufficient that it has a different metal component from the organometallic compound (A) and is gaseous, and there are no particular restrictions. do not have. Examples of the other metal compound (B) include metals or semimetals such as lead, bismuth, thallium, zinc, aluminum, cadmium, mercury, gold, silver, platinum, cobalt, nickel, iron, tin, silicon, and germanium. Organometallic compounds having a metal-carbon bond between an alkyl group, etc., and hydrides, alkoxides, carbonylates, metallocene compounds, halides, hydroxides, oxides, carbides, and nitrides of these metals and semimetals. , sulfide, etc., and these metal compounds may be used alone or in combination of two or more.

These metal compounds also include the organometallic compound (
As in case A), the decomposition reaction is an exothermic reaction,
Those with low bond dissociation energy and relatively high vapor pressure are preferred. In addition to the above-mentioned 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,
For example, iron carbonyl, nickel carbonyl, chromium carbonyl, molybdenum carbonyl, tungsten carbonyl, etc. are preferable because they have low bond dissociation energy to decompose into metal atoms. Of course, these other metal compounds (B) need to have a metal component different from that of the organometallic compound (A).

The above organometallic compound (A) and metal compound (B)
By irradiating a part of this system with energy rays such as the laser described below,
An exothermic chain reaction can proceed to produce a composite metal compound.

Here, chain reactions are mainly decomposition reactions and complex reactions.

Furthermore, "exothermic" means that the total heat balance in the reaction is negative.

A concrete explanation is as follows.

As the organometallic compound (A), for example, a compound represented by the general formula, M"R"m (M2 = metal, R2: alkyl group, m: positive rational number), and as the metal compound (B), for example, the general formula, M3 R3p (M3: metal different from M'', R3, there are no particular restrictions, but
p which is an alkyl group, a halogen group, a carbonyl group, etc.
ro or a positive rational number) at a molar ratio of 1:x (x is a positive rational number).
'p-+M'-M3x +R'm-R''px.In this reaction, D A +D m -D c
-D, (When it becomes 0, an exothermic reaction occurs, and the heat promotes a chain reaction, producing a composite metal compound M2-M3x. Here, DA is a bond where M"R"m decomposes into M2+mR' is the dissociation energy, D is M S R3
X@ of the bond dissociation energy when p decomposes into M3+pR3
, and DC is M”−M from M2 and xM3
3x, and DD is m R”
It is the total bond energy that generates Rm''-R3px from and xpR''.

In the method of the present invention, the organometallic compound (
The vapor concentration of A) is at least 101' molecules/molecule, preferably 1
It is necessary that the IQ is 0'' molecules/rr+1 or more, more preferably IQ 17 molecules/mQ or more. This concentration is 10
If it is lower than 1' molecule/rmQ, the concentration of the chain-initiating active species is too low, making it difficult for the active species to react with other metal compounds (B) during their lifetime, resulting in deactivation of the active species. This makes it difficult for a chain reaction to start. Further, the progression of chain reactions is also less likely to occur.

Appropriate conditions can be selected for the vapor concentration of the organometallic compound (A) depending on the absorption coefficient of the organometallic compound with respect to irradiation energy rays. 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 vapor concentration of the other metal compound (B) is appropriately selected depending on the types of the organometallic compound (A) and the metal compound (B).

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, 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 it is better to be low in order to cause a chain decomposition reaction. The concentration is selected within a range of 5 times or less of the total concentration including the vapor concentration of compound (B).

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 produce 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. are used, but 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 pulsed laser, and specifically, an excimer laser that oscillates in the ultraviolet region, a nitrogen laser, a carbon dioxide laser that oscillates in the infrared region, a carbon oxide laser, or a YAG laser. −
Examples include glass lasers, ruby lasers, alexandrite lasers, harmonics such as YAG lasers that oscillate in the visible region, copper vapor lasers, all-vapor lasers, dye lasers, argon ion lasers, krypton ion lasers, etc. It will be done.

In general, the organometallic compound (A) has a large absorption in the ultraviolet region, so if a laser that oscillates in the ultraviolet region is used, active species can be easily generated at a high density. can.

An excimer laser is particularly suitable because it has 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, breakdown by the laser can generally be caused, so chain decomposition can be caused.

Although the energy beam in the present invention may be a continuous energy beam, it is preferable that a pulsed beam 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 keep the irradiation time very short to maintain a high concentration of active species generated per unit time.
This is preferably within 10-3 seconds, particularly preferably within 10-4 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.

In addition, at that time, the energy density of the irradiation ray is I Ca1
It is sufficient if the density is 10-4 or more, and if the density is lower than this, the chain decomposition reaction will hardly start.The density is preferably 10-3 or more.

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 tetramethyl lead 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 10 or more eyes/ran, preferably 10'6 eyes/m
Active species with a high concentration of Q or higher are generated, and an exothermic chain reaction caused by these active species occurs sequentially, and the organometallic compound (A) and metal compound (B) are almost completely decomposed instantly. , a complexing reaction between atoms occurs, and fine particles of a complex metal compound are generated.

The diameter of the fine particles of the composite metal compound thus obtained is 5 μm or less, but most of the particles are 0.5 μm or less.

[Example 1] 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 A tetramethyl vessel was placed in a 100 mQ reaction vessel at 22°C with a vapor concentration of 4.9×10” molecules/mQ (15To
r r), further add trimethyl bismuth at a vapor concentration of 1.6
), and a laser beam from an ArF excimer laser (193 nm) was applied through a synthetic quartz window.
Only pulses (energy density 25 m J 7 cm2, pulse eilo-s seconds) were irradiated to produce 100 mJ (9,
When energy (7xlO" photons) was input, most of the molecules decomposed while producing orange light, and the particles became 5μ in size.
18 mg of composite metal fine particles (X) with a size of 18 mm or less were produced.

In addition, the vapor concentration of tetramethyl lead was 3.3 x 1017 molecules/ml (10 Torr), and the vapor concentration of trimethyl bismuth was 3.3 x 1017 molecules/m (L (10
When laser irradiation was performed in the same manner, 18 mg of composite metal fine particles (Y) with a particle size of 2 μm or less were produced.

Furthermore, the vapor concentration of tetramethyl lead was increased to 1.6Xlo17
Molecule/ml! (5 Torr) and the vapor concentration of trimethyl bismuth to 4.9 x 1017 molecules/mA (15 Torr).
r), and when laser irradiated in the same way, the particle size was 1μ
18 m9 of composite metal fine particles (Z) with a size of less than m were generated.

These results show that the organometallic compound decomposes instantaneously at a rate of 670 molecules per photon. This is approximately 700 times more energy efficient than conventional methods.

EPMA these composite metal fine particles (electron probe m1cr.

Analyzer), Figure 1 shows that
As shown in Figures 2 and 3, the image of lead and the image of bismuth match, and the intensity ratio is almost equal to the abundance ratio in the gas phase, so composite metal fine particles reflecting the composition of the gas phase It was revealed that a single fine particle of lead or bismuth was not produced. In addition, Figure 1,
FIGS. 2 and 3 are EPMA analysis images of composite metal fine particles (X), (Y), and (z) for lead and bismuth, respectively.

Example 2 Tetramethyl lead with a vapor concentration of 3.3 x 10 molecules/
Tetramethyltin was further added to the vapor concentration of 1.6x IQ 1 so that mQ (10Torr)
7 molecules/1 liter (5 Torr), and when this was irradiated with laser light from an excimer laser in the same manner as in Example 1, it was almost decomposed with orange light emission, and particles were formed. 16 mg of composite metal fine particles (W) with a diameter of 0.3 μm or less were produced. When this composite metal fine particle (W) was analyzed by EPMA, as shown in Figure 4, one pulse of laser irradiation also decomposed tetramethyltin, which does not normally cause a chain decomposition reaction, and formed composite metal fine particles. It has become clear that the composition of the gas phase reflects the composition of the gas phase.

Comparative Example 1 Same as Example 1, tetramethyl lead 4.9×10 17 molecules/ml (15 Torr) and trimethyl bismuth 1.
7xl□+y molecules/m11 (5 Torr) was weighed into a 100 d reaction vessel, and one pulse of ArF excimer laser (193 nm) was applied through a synthetic quartz window (energy density 2.5 x 10-'J/cI + lζ pulse width 10).
-8 seconds) and input energy of 10-4 Joules, no chain decomposition reaction was observed.

Comparative Example 2 Same as Example 1, 3.3×10 molecules of tetramethyl lead/
mQ (0,01Torr) and trimethyl bismuth 3.3X10'4 molecules/mn, (0, OITorr)
When the sample was weighed in a 100 mm reaction vessel and irradiated with one pulse of ArF excimer laser (193 nrn) through a synthetic quartz window, no chain decomposition reaction was observed.

Comparative Example 3 Same as Example 1, ΔH is 30 k all/mai
Tetramethyltin 4.9X I O” molecule/
rn Q(15To r r) and Δ11 are 65 k
e ai/mol.

of tetramethylgermanium 1.7X101T molecules/m
11 (5 Torr) was weighed into a 100ml reaction vessel, and an ArF excimer laser (
When only one pulse of radiation (193 nm) was applied, no chain decomposition reaction was observed.

[Effects of the Invention] According to the method of the present invention, a high-quality composite metal compound consisting of two or more metal elements can be produced from the vapor of a metal compound at low cost and with a small amount of input energy by irradiating one pulse of energy rays. It can be produced extremely efficiently, and because it mixes two or more metal compounds with different metal elements in the gas phase and generates fine particles of the composite metal compound while causing a decomposition reaction, the metal in the fine particles is In addition to the extremely good mixing of elements, the composition in the gas phase is reflected in the fine particles, making it easy to control the composition.

The composite metal compound obtained by the method of the present invention has extremely good quality and is suitably used as, for example, an electronic material.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are photographs substituted for drawings of EPMA analysis images showing the metal structures of different examples of composite metal fine particles obtained by the method of the present invention, respectively. Procedural amendment dated IO 2, 1999

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,
The organometallic compound and another gaseous metal compound having different metal components are mixed and present, and 1c is present in a part of the system.
By irradiating energy rays with an energy density of 10^-^4 joules or more per m^2, a high concentration of active species caused by the mixture is generated in a part of the system, and then heat generation caused by this active species is generated. 1. A method for producing a composite metal compound, the method comprising producing the composite metal compound by a chain reaction. 2. The manufacturing method according to claim 1, wherein the composite metal compound is in the form of fine particles.