JPH06145180A - Purification of organophosphorus compound - Google Patents

Abstract

PURPOSE:To provide an industrially advantageous purification method capable of effectively and safely purifying an organophosphorus compound as a raw material for epitaxial growth to a high purity grade generally required for a raw material of a compound semiconductor. CONSTITUTION:An organophosphorus compound represented by formula RaH3-aP [R is a 1 to 4C alkyl; a is 1 to 3] is brought into contact with active carbon to remove impurities. As the active carbon, e.g. even an active carbon produced from coconut husk, coal pitch, petroleum pitch, sawdust, etc., can recommendably be used and there is no special limitation about its shape. The amount of the active carbon to be used is preferably 0.1 to 100 pts.wt., practically 10 to 50 pts.wt. per 100 pts.wt. organophosphorus compound in general and varied according to the kind or the amount of impurities to be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying an organophosphorus compound useful as a material for epitaxial growth for producing a compound semiconductor.

[0002]

2. Description of the Related Art In recent years, compound semiconductors have been widely used in light emitting diodes, semiconductor lasers, high speed operation transistors (HEMTs) and the like. In manufacturing compound semiconductors, metal organic chemical vapor deposition (MOCV Meta
Recently, a method of epitaxially growing a crystal by means of lorganic chemical vapor deposition has been actively performed. As a compound semiconductor manufactured by such a method,
For example, there is a III-V group compound semiconductor. Phosphine containing phosphorus is often used as a raw material for the group V side.

In the method of using phosphine as a raw material for the group V side, safety is a problem. Phosphine is toxic. Moreover, since it is a gas at room temperature, it must be used at high pressure in the production of compound semiconductors. Use of toxic gas at high pressure is dangerous. In order to overcome such problems of phosphine, use of monoalkylphosphine has recently been proposed. Epitaxially grown films dislike carbon inclusion. Monoalkylphosphine is attracting attention as an alternative material because it has less carbon contamination in the epitaxial growth film and has lower toxicity than phosphine.

Monoalkylphosphine is synthesized by reducing phosphonyl chloride or phosphonous acid, but it is also synthesized by reacting phosphine with an olefin. The latter is easier for mass production. To synthesize a monoalkylphosphine by reacting a phosphine with an olefin, a sulfonic acid compound is used as a catalyst. Therefore, the monoalkylphosphine obtained by synthesis usually contains a trace amount of a sulfur compound even after purification. Others, cadmium, magnesium, calcium,
Compounds such as iron, arsenic and silicon, and hydrocarbons used as a reaction solvent are also contained as trace impurities. These trace impurities cause troubles in the electrical and optical characteristics of the epitaxially grown crystal. When making semiconductors, organometallic compounds are generally purified by high precision distillation. However, until now, the precision distillation purification method alone has
It was not possible to sufficiently obtain the high-purity monoalkylphosphine required for the production of compound semiconductors.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is effective to use an organophosphorus compound as a material for epitaxial growth up to the high purity generally required as a raw material for a compound semiconductor. Moreover, it is an object of the present invention to provide an industrially advantageous purification method that can be purified safely.

[0006]

The method for purifying an organophosphorus compound of the present invention, which has been made to achieve the above object, comprises contacting an organophosphorus compound represented by the following general formula 1 with activated carbon,
Remove impurities.

R _a H _3-a P (1) In the formula, R is an alkyl group having 1 to 4 carbon atoms. a is 1
It is an integer of 3. This method is particularly preferably applied when the impurities in the monoalkylphosphine are to be removed. In that case, as the monoalkylphosphine,
Examples thereof include mono-1,1-dimethylethylphosphine, mono-1-methylpropylphosphine and monoethylphosphine. These are the manufacture of compound semiconductors,
Used as a material for epitaxial growth.

Monoalkylphosphine is a sulfonic acid compound used as a catalyst in the synthesis, a metal compound, an unreacted olefin which was introduced as a reaction product and could not be separated during precision distillation purification, and a hydrocarbon compound used as a solvent. Etc. are contained as trace impurities.
In other words, a non-metal compound containing at least one element of sulfur, silicon and oxygen, a metal compound containing a metal such as cadmium, magnesium, calcium, iron, manganese or arsenic, a hydrocarbon compound as a solvent, etc. Contains as an impurity.

Examples of the activated carbon through which the above-mentioned organophosphorus compound is passed in contact are, for example, palm shell, coal pitch, petroleum pitch,
It may be manufactured from sawdust or the like, and its shape and form are not particularly limited. However, granules or fibrous substances are particularly preferable. Considering the handling property or the operability of the purification treatment, the granular material of 10 to 80 mesh is preferable. Even fibrous activated carbon (activated carbon fiber) can be expected to improve the adsorption speed and has high practicality.

The amount of activated carbon used varies depending on the kind and amount of impurities to be adsorbed and removed, but is generally 0.1 to 100 parts by weight, and practically 10 to 50 parts by weight, per 100 parts by weight of the organic phosphorus compound. preferable.

In the purification, the activated carbon is sufficiently dried in advance, and the dried activated carbon is brought into contact with the organic phosphorus compound. The activated carbon may be dried by heating at a temperature of about 250 to 300 ° C. When heated, the water adhering to the activated carbon is removed, and the deterioration of the adsorption function, the oxidation or deterioration of the organic phosphorus compound to be purified, and the decrease of the yield are prevented. The activated carbon may be brought into contact with the organic phosphorus compound by precision distillation of the organic phosphorus compound, and then the organic phosphorus compound is brought into contact with the activated carbon in a gas or liquid state. The contact may be performed by mixing activated carbon and an organic phosphorus compound or by passing through a column packed with activated carbon. If the organic phosphorus compound to be purified is liquid at room temperature and pressure and is easily gasified, it is rather gasified and contacted.

According to such a method, for example, a mono-
Trace impurities can be efficiently removed from 1,1-dimethylethylphosphine and the like. In addition to monoalkylphosphine, it can also be efficiently removed from dimethylphosphine, diethylphosphine, trimethylphosphine, and triethylphosphine.

[0013]

[Activity] Activated carbon is a non-metallic compound containing at least one element selected from sulfur, silicon and oxygen, a metallic compound containing at least one metal selected from cadmium, magnesium, calcium, iron and manganese, and a solvent. And selectively adsorbs hydrocarbon compounds and the like. Little adsorption of organophosphorus compounds.

[0014]

As described above in detail, according to the present invention, trace impurities that cannot be completely removed by precision distillation can be efficiently and efficiently removed from an organic phosphorus compound, and a raw material for producing a compound semiconductor can be obtained. It is possible to obtain a high-purity organophosphorus compound generally required as. Moreover, the method is a simple method of contacting with activated carbon, and the yield is high.
It is extremely advantageous in industry.

[0015]

EXAMPLES Examples of the present invention will be described below. Example 1 120 g of isobutene was placed in an autoclave reaction vessel having a volume of 1 liter and replaced with nitrogen gas or helium gas.
100 g of n-decane and 120 g of phosphine were charged.
To this, 140 g of methanesulfonic acid was added as a catalyst under pressure, and the mixture was stirred for 2 hours while maintaining the temperature inside the container at 60 ° C.
Isobutene was reacted with phosphine. During the reaction, the pressure inside the autoclave increased to about 30 kg / cm ² . When the temperature had dropped to 30 ° C. after the reaction was completed, unreacted phosphine was exhausted from the autoclave. When the reaction liquid was analyzed by gas chromatography, it was found that mono-1,1-dimethylethylphosphine was synthesized. The reaction yield was 44.4% based on isobutene.

The resulting reaction solution was allowed to stand still for liquid separation, and then precision distillation was carried out to obtain 69.0 g of crude mono-1,1-dimethylethylphosphine. The obtained crude mono-1,1-
A part of dimethylethylphosphine was analyzed using a high temperature emission spectrophotometer (ICP) and gas chromatography, and sulfur and metal components (F
e, Mg, Mn, Si, As) and other hydrocarbon contents were measured. The results are shown in Table 1 as before treatment.

Table 1 Impurity n-decane Fe Mg Mg Mn As Si S Before treatment (ppm) 0.5 Trace trace Trace trace 15 259 After treatment (ppm) × × × × × 276 In Table 1, x is measured Indicates that the vessel did not detect its presence.

Granular activated carbon of 30-60 mesh (manufactured by Nishio Industry Co., Ltd.) in a glass tube of 20 cm × 1.5 cmΦ.
10 g was charged. Then, the above-mentioned crude mono-
1,1-Dimethylethylphosphine was flowed down at room temperature at a flow rate of 5 liters / hour to obtain 45.0 g (0.50 mol).
I got a high purity product.

A portion of the purified mono-1,1 dimethylethylphosphine was analyzed using a high temperature emission spectrophotometer and gas chromatography in the same manner as above. The results are shown in Table 1 as after treatment.

From the above results, the activated carbon goes beyond the usual concept of adsorption and substantially removes a large amount of a small amount of sulfur-containing hydrocarbons and various metal compounds as impurities, and further performs fine distillation. It was found that the hydrocarbons that could not be completely removed were also removed.

Comparative Example 1 Same as Example 1, but synthetic zeolite 5A was used instead of activated carbon. The results are shown in Table 2.

Table 2 Impurities n-decane Fe Mg Mg Mn As Si S Before treatment (ppm) 0.7 Traces Traces Traces 14 260 After treatment (ppm) 0.6 Traces Traces Traces 13 255 Example 1, Comparative Example 1 From such experiments, it was found that the adsorbents such as activated alumina and synthetic zeolite 5A cannot substantially adsorb and remove the sulfur-containing hydrocarbon compounds, the metal compounds and the hydrocarbons. It has been found that the use of activated carbon makes it possible to efficiently purify mono-1,1-dimethylethylphosphine to a purity generally required for producing an intermetallic compound semiconductor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromi Osaki, 28, Nishi-Fukushima, Chugiki-mura, Nakakubiki-gun, Niigata Prefecture 1 Shinetsu Chemical Industry Co., Ltd. Synthetic Technology Laboratory (72) Inventor Tadashi Sugiya Tamura-gun, Fukushima Prefecture Miharu-cho, 3 Tenno-mae, Nihon Chemical Industry Co., Ltd. Miharu Plant (72) Inventor Tomio Yanai, 9-15-1, Kameido, Koto-ku, Tokyo Nihon Kagaku Kogyo Co., Ltd.

Claims (3)

[Claims] 1. The following general formula 1 R _a H _3-a P (1) (wherein R is an alkyl group having 1 to 4 carbon atoms, and a is 1 to 1).
A method for purifying an organic phosphorus compound, which comprises contacting the organic phosphorus compound represented by 3) with activated carbon to remove impurities. 2. The method for purifying an organophosphorus compound according to claim 1, wherein the organophosphorus compound is a monoalkylphosphine. 3. The monoalkylphosphine is mono-
The method for purifying an organophosphorus compound according to claim 1 or 2, which is 1,1-dimethylethylphosphine.