JPH10130288A - Production of monoalkylarsine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monoalkylarsine suitable as a raw material for producing thin films of a semiconductor at a low cost in an improved yield and productivity. SOLUTION: In producing a monoalkylarsine, when preparing dihalogenated alkylarsine by preparing a Grignard reagent from a halogenated alkyl and magnesium and successively reacting an arsine trihalide with the Grignard reagent, the magnesium salt is easily separated from a slurry and the yield of a dihalogenated alkylarsine is enhanced by preventing generation of colloidal magnesium hydroxide in the magnesium salt which is a byproduct by bringing zeolite to present in the system to remove water contaminated from an organic solvent, manufacturing raw materials and the environment during the reaction. The monoalkylarsine is produced by reducing the dihalogenated alkylarsine and distilling the reduced product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to MOCVD (Me
tal Organic Chemical Vapor
The present invention relates to a method for producing monoalkylarsine as a raw material when producing a compound semiconductor thin film by a Deposition method or the like.

[0002]

2. Description of the Related Art A thin film of a III-V compound semiconductor such as gallium-arsenic is an essential material for manufacturing electronic devices, opto devices and the like. As a method of forming such a compound semiconductor thin film, LPE (Liquid Phase) is used.
e Epitaxy), halide CVD, MBE (Mo
(Regular Beam Epitaxy), MOM
BE (Metal Organic Molecular)
r Beam Epi-taxy), MOCVD and the like. Among these methods, MOCVD and MOMBE
Is widely used because it is not necessary to maintain a high vacuum in the crystal growth system, and it is easy to form a multilayer structure. An organic metal compound packed in a bubbler or a hydride packed in a cylinder is used as a group III or group V raw material at the time of producing a thin film by these apparatuses.

In selecting between an organometallic compound and a hydride,
Most of hydrides are highly poisonous gases, and there is anxiety in handling a large amount of compound semiconductor thin films with mass production thereof. For example, as an arsenic source, monoalkylarsine, which is an organometallic compound, in particular, tertiary butylarsine (TBA) having an alkyl group as a tertiary butyl group in place of arsine, which is a hydride, is a liquid and has relatively low toxicity. Attention has been paid to the fact that a compound semiconductor thin film comparable to that grown using arsine as a raw material can be obtained even if this is used.

As a method for producing monoalkylarsine, the following method is known (Rec. Trav. C).
him. 82, (1982) p202). A. The monoalkyl halide is reacted with magnesium in an organic solvent to make a Grignard reagent. I. This Grignard reagent and arsenic trihalide are used in a molar ratio of 1
The reaction is performed in an organic solvent on a one-to-one basis to obtain an alkylarsine dihalide. C. By-product magnesium halide is removed, and alkylarsine dihalide is isolated and purified. D. When the dihalogenated alkyl arsine is solid at room temperature, it is dissolved in an appropriate organic solvent and reduced with a reducing agent such as lithium aluminum hydride to obtain a monoalkyl arsine. E. The synthesized monoalkylarsine is purified by distillation.

[0005]

When monoalkylarsine is produced by such a method, trace amounts of water are contained in the monoalkyl halide, arsenic trihalide as a raw material, and the organic solvent used as a solvent in the reaction step. Containing a Grignard reagent and arsenic trihalide in a molar ratio of 1: 1
In the process of obtaining an alkyl arsine dihalide by reacting in an organic solvent, colloidal magnesium hydroxide is formed by the water and magnesium in the magnesium halide by-produced, and the viscosity of the slurry is reduced due to the colloidal magnesium hydroxide. There is a problem that the solid-liquid separation becomes extremely difficult due to the increase, and the yield of the target product is significantly reduced.

In order to avoid such difficulties and facilitate the separation of the magnesium salt, the viscosity may be reduced by diluting with a suitable organic solvent prior to solid-liquid separation, or the Grignard reagent and trihalide may be mixed. Efforts have been made to slow down the reaction with arsenic or at a liquid temperature as high as possible to grow magnesium halide crystals to lower the viscosity. However, with these methods,
Productivity decreases and costs increase.

The present invention solves the above-mentioned problems in the production of monoalkylarsine. When an arsenic trihalide is reacted with a Grignard reagent to form an alkylarsine dihalide, the magnesium salt produced as a by-product is contained. An object of the present invention is to provide a method for producing a monoalkylarsine which can prevent separation of a magnesium salt from a slurry by preventing generation of colloidal magnesium hydroxide, and can improve the yield. .

[0008]

According to the method for producing monoalkylarsine of the present invention, a Grignard reagent is synthesized from an alkyl halide and magnesium, and the Grignard reagent and arsenic trihalide are reacted in an organic solvent to obtain a Grignard reagent. When zeolite is added to make alkylarsine halide, the entire amount of by-produced magnesium salt is converted into magnesium halide, and after separating and removing this magnesium halide, dihalogenated alkylarsine is reduced and distillation is performed. Thus, a monoalkylarsine is produced.

When the Grignard reagent is reacted with an arsenic trihalide in an organic solvent to form an alkylarsine dihalide, the added zeolite adsorbs water present in the reaction system and generates a magnesium salt by-produced. The production of magnesium hydroxide is prevented, and the entire amount of the magnesium salt is converted into magnesium halide, thereby facilitating the separation and removal of magnesium halide and increasing the yield of alkylarsine dihalide. This is reduced to monoalkylarsine, and then purified by distillation to obtain monoalkylarsine with high purity.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing a monoalkylarsine of the present invention, a Grignard reagent is synthesized from an alkyl halide and magnesium, and the Grignard reagent and an arsenic trihalide are reacted in an organic solvent to form an alkyl dihalide. A zeolite is added to form arsine and the entire amount of by-produced magnesium salt is converted into magnesium halide.After separating and removing the magnesium halide, the dihalogenated alkylarsine is reduced and distilled to perform monoalkylation. Manufacture arsine.

Organic chemicals such as alkyl halides contain a considerable amount of water that accompanies raw materials for production and is absorbed from the atmosphere during production or during the production process. In particular, it is no exaggeration to say that water is the impurity most contained in the organic solvent. In addition, since the final purification of arsenic trihalide, which is the other raw material, is distillation, moisture is inevitably mixed due to distribution equilibrium.

When a Grignard reagent and an arsenic trihalide are reacted in an organic solvent to produce an alkylarsine dihalide, magnesium in the Grignard reagent is released and combines with the halogen to produce a magnesium halide. However, if water is present in the system, magnesium hydroxide, particularly colloidal magnesium hydroxide, is mixed into the magnesium halide, and as a result, the viscosity of the slurry is extremely increased, making solid-liquid separation difficult. By fixing the water in the system with an adsorbent to prevent the production of magnesium hydroxide without participating in the reaction, while controlling the reaction rate of the Grignard reagent and arsenic trihalide, the crystal growth of magnesium halide To improve its filterability and facilitate solid-liquid separation leads to not only an improvement in productivity but also an improvement in yield.

An adsorbent is present in the system when removing water in an organic solvent or arsenic trihalide with an adsorbent, or reacting a monoalkyl halide with magnesium in an organic solvent to produce a Grignard reagent. There is also a method, but the method of adding an adsorbent when reacting a Grignard reagent with arsenic trihalide to obtain an alkylarsine dihalide is excellent because the organic solvent easily absorbs moisture.

Activated clay, activated alumina,
There are silica gel, activated carbon, zeolite, etc., but if the adsorbent becomes fine particles in the system, it will be difficult to separate it, so the original purpose can not be achieved, and if the adsorbent elutes the metal element, it will increase the load of the purification process Therefore, it is not preferable that the adsorbent easily desorbs the water adsorbed by the adsorbent, and the adsorbent is required to have acid resistance because arsenic trihalide is present in the system. An adsorbent suitable for these requirements is zeolite.
In addition, zeolite is suitable because it has a high adsorption capacity even when the concentration of the substance to be adsorbed is low, is hardly affected by temperature on adsorption, and further preferentially adsorbs polar substances and unsaturated compounds.

[0015] As zeolite, there are more than 100 kinds of natural and synthetic zeolites. Synthetic zeolites having a uniform pore distribution and an appropriate pore diameter for adsorbing and removing water are provided. Is preferred. Synthetic zeolites are also referred to as molecular sieves. Representative types of synthetic zeolites are 3A, 4A, 5A, 10X and 13X types. Although the 3A type can adsorb water, it is not preferable because the adsorption speed is slow due to the pore diameter. Any other 4A, 5A, 10X and 13X types can be used. Among them, the 13X type is preferable because the water adsorption speed is high and impurities other than water are also adsorbed and removed.

[0016]

Embodiments of the present invention will be described below. All operations in the examples were performed under an inert atmosphere.

Embodiment 1 A. Synthesis of Grignard Reagent 1200 ml of diethyl ether was added to 57.8 g (2.4 mol) of magnesium, and 284 ml (2.4 mol) of tert-butyl chloride was added dropwise. After the completion of the dropping, the supernatant was transferred to a dropping tube to obtain 1250 ml of a black liquid. The measured titer was 1.42 mol / l, and the yield was 80%.

B. Synthesis of tertiary butyl dichloroarsine 1000 ml of diethyl ether was added to 345 g (1.91 mol) of arsenic trichloride, and then 20 g of zeolite 13X type which had been degassed under vacuum at a temperature of 200 ° C. overnight was added. 1250 ml (1.91 mol) of a diethyl ether solution as a reagent was added dropwise while cooling so that the temperature of the reaction vessel became −10 ° C. or less. After dropping, the liquid temperature was returned to room temperature, and the diameter was 285 mm.
100mmH with nitrogen using 3G glass filter
_The mixture was pressurized to ₂ O and filtered. The filtration time was 2 hours and 20 minutes. The amount of the obtained filtrate was 1750 ml, and the concentration of tertiary butyl dichloroarsine therein was analyzed by gas chromatography to find that it was 21.7%.
The yield here was 78%.

C. Synthesis of Mono-tert-butylarsine The obtained filtrate was distilled under reduced pressure of 50 Torr at a temperature of 30 ° C. using a still with a fractionator and a reflux condenser, and an organic solvent was distilled off. After raising the temperature to 65 ° C., the pressure was reduced to 10 Torr, and distillation was performed to recover a white solid. An appropriate amount of diethylene glycol dimethyl ether is added to this solid to form a solution.

On the other hand, while maintaining the temperature of a liquid in which lithium aluminum hydride is suspended in diethylene glycol dimethyl ether at -25 ° C. or lower, diethylene glycol dimethyl ether in which a white solid is dissolved is added dropwise with stirring. After completion of dropping, the temperature is 80 ° C and the pressure is 150
A colorless and transparent liquid containing monotertiary-butylarsine as a main component is recovered by distillation under reduced pressure at Torr.

D. Purification of Monotertiary Butyl Arsine by Distillation The collected colorless and transparent liquid is subjected to atmospheric distillation at a temperature of 72 ° C. using a distillation apparatus equipped with a view column to recover a liquid containing 99% or more of monotertiary butyl arsine. .

Example 2 345 g (1.91 mol) of arsenic trichloride during the synthesis of tertiary butyl dichloroarsine
The same operation as in Example 1 was carried out except that the amount of diethyl ether relative to 1) was changed to 500 ml. The filtration time was 2 hours. The amount of the filtrate obtained was 1150 ml, and the concentration of tertiary butyl dichloroarsine therein was analyzed by gas chromatography. As a result, the yield was 27.2% and the yield here was 66%.

Example 3 The same operation as in Example 1 was performed, except that the type of zeolite used in the synthesis of tertiary butyl dichloroarsine was 4A. Filtration time is 2
The time was 30 minutes. Also, the obtained filtrate amount was 1700.
The concentration of tertiary butyl dichloroarsine therein was analyzed by gas chromatography, and as a result, the yield was 21.9% and the yield here was 76%.

Comparative Example 1 The procedure of Example 1 was repeated except that zeolite was not used during the synthesis of tertiary butyl dichloroarsine. The filtration time was 4 hours 10 minutes. Further, the obtained filtrate amount was 1650 ml, and the concentration of tertiary butyl dichloroarsine therein was analyzed by gas chromatography. As a result, the yield was 21.1% and the yield here was 71%.

Comparative Example 2 The procedure of Example 2 was repeated except that zeolite was not used during the synthesis of tertiary butyl dichloroarsine. The filtration time was 6 hours and 40 minutes. The amount of the obtained filtrate was 900 ml, and the concentration of tertiary butyl dichloroarsine therein was analyzed by gas chromatography. As a result, the yield was 27.5% and the yield here was 52%.

From the above results, it can be seen that the use of zeolite during the synthesis of tertiary butyl dichloroarsine shortens the filtration time and improves the yield.

[0027]

As described above, according to the method for producing monoalkylarsine of the present invention, when arsenic trihalide is reacted with Grignard reagent to form alkylarsine dihalide, zeolite is present in the system. By adsorbing and removing water mixed during the reaction from the organic solvent, production raw materials, atmosphere, etc., and preventing the generation of colloidal magnesium hydroxide in the by-product magnesium salt, the magnesium salt from the slurry is removed. Facilitates the separation of
And the yield can be improved. Therefore, it is possible to improve productivity and produce monoalkylarsine suitable for a raw material for producing a semiconductor thin film at low cost.

Claims (1)

[Claims] 1. A method for synthesizing a Grignard reagent with an alkyl halide and magnesium, reacting the Grignard reagent with arsenic trihalide in an organic solvent to obtain an alkylarsine dihalide, followed by filtration. To produce monoalkylarsine by reducing and distilling alkylarsine dihalide, and then distilling magnesium alginate when adding a zeolite to react a Grignard reagent with arsenic trihalide in an organic solvent. Avoiding the production of magnesium hydroxide in the salt, the total amount is magnesium halide,
A method for producing monoalkylarsine, comprising distilling off magnesium halide after filtration to reduce dihalogenated alkylarsine.