JPH0341404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing low halogenated silane or monosilane from halogenated silane, and more specifically, for producing low halogenated silane or monosilane at low cost and easily by bringing halogenated silane into contact with a specified catalyst. Regarding the method.

In particular, monosilane is a useful substance in the semiconductor industry as a raw material for high-purity semiconductor grade silicon or amorphous silicon for solar cells, and as a raw material for epitaxial use, and demand is expected to further increase in the future. Therefore, an excellent method for producing monosilane that is cheaper and easier is desired.

Traditionally, monosilane has been produced by (1) reacting magnesium silicide with ammonium chloride in liquid ammonia, and (2) reacting tetrachlorosilane with LiAlH ₄ in ether.
(3) A method in which trichlorosilane is subjected to a disproportionation reaction with an anion exchange resin containing a tertiary amino group or a quaternary ammonium group (4) A method in which hydrogen gas is applied to metallic silicon under high temperature and high pressure conditions. A method of reacting using fine Ni powder is known.

However, although the above method (1) has been put into practical use industrially, it requires a reaction at extremely low temperatures, the preparation of raw materials is complicated, and the equipment costs are high considering the reuse of by-product higher-order silane. In (2), LiAlH ₄ is extremely expensive, so it is not suitable for mass production and has little practicality. Although (3) is superior in terms of mass productivity and energy cost, there is a problem with the thermal stability of the anion exchange resin. Since (4) is a reaction at high temperature and high pressure, it has the drawbacks of high equipment costs and by-product of higher-order silane.

In view of the above-mentioned problems particularly in the method for producing monosilane, the present inventors have conducted extensive research into a method for producing inexpensive and simple monosilane with the main purpose of producing monosilane. As a result, low halogenated silanes or monosilanes can be easily obtained by catalytically contacting halogenated silanes with organometallic compounds in which metals or metal salts are chemically bonded to hydrocarbons, organic nitrogen-containing compounds, or organic phosphorus-containing compounds. This discovery led us to provide the present invention.

The halogen silane that is the raw material of the present invention includes:
General formula SiHX ₃ , SiH ₂ X ₂ , SiH ₃ X (X: halogen)
For example, chlorosilane such as trichlorosilane, dichlorosilane, and monochlorosilane are applicable, but bromosilane, bromosilane,
Fluorosilane and iodosilane can also be used. Therefore, according to the present invention, the above-mentioned halogensilanes are reduced in halogenation, and each
From SiHX ₃ , SiH ₂ X ₂ , SiH ₃ X, SiH ₄ ,
From SiH ₂ X ₂ , SiH ₃ X, SiH ₄ , and from SiH ₃ X
SiH ₄ can be produced depending on the purpose, but
In particular, SiH ₄ (monosilane) can be suitably obtained from SiH ₂ X ₂ (dichlorosilane).

As the organometallic compound specified in the present invention, known compounds can be used without particular limitation. That is, the hydrocarbon compound, organic nitrogen compound, and organic phosphorus-containing compound of the present invention may be any compound that generally chemically bonds with a metal or a metal salt to form an organic metal compound. Examples of hydrocarbon compounds include olefins such as ethylene and propylene, benzene, dicyclopentadienyl,
These include low-molecular compounds such as biscyclooctadiene, and high-molecular compounds such as polystyrene, polystyrene resin crosslinked with divinylben, and acrylic resin. Examples of organic nitrogen-containing compounds include alkylamines such as methylamine and ethylamine, low molecular weight compounds such as nitriles such as ε-caprolactam, acrylonitrile, and phenylisonitrile, and polyethyleneimine, polyamide, and polyvinylpyridine resin. , nylon, and styrene-divinylbenzene-based ion exchange resins bonded with substituents such as -CH ₂ N(CH ₃ ) ₂ and -CH ₂ CN are suitable. Examples of organic phosphorus-containing compounds include low molecular weight compounds such as triphenylphosphine, triphenylphosphine, and triethylphosphite, as well as styrene-divinylbenzene resins bonded with diphenylphosphine-CH ₂ PPH ₂ and divinylbenzene. - High molecular compounds such as allyl chloride copolymers are preferred. On the other hand, examples of metals or metal salts include Pt, Pd, Ir,
In addition to Group 8 metals such as Rh, Ru, Fe, Ni, and Co,
Examples include metals such as Ti, cr, Cu, Ag, Zn, Al, W, Mo, and V, or their chlorides and carbonyl compounds. The organometallic compound is generally in the form of a predetermined metal or metal salt bonded to the above hydrocarbon compound, organic nitrogen-containing compound, and organic phosphorus-containing compound as an ion exchange or a complex. For example, in addition to Pd(Ph ₃ ) ₂ Cl ₂ ] and [Pt(PPh ₃ ) ₂ Cl ₂ ], organometallic compounds that are complexes with Group 8 metals or metal salts are particularly suitable for use in ion exchange resins. It will be done.

In the present invention, halogensilane can be used in either gas or liquid form, and the organometallic compound used as a catalyst can also be used in solid, liquid, or gas form. Therefore, the reaction form of the present invention is extremely flexible, and an advantageous form may be selected as required. For example, when both the halogen silane and the organometallic compound are provided as liquids to the reaction system and a liquid phase-liquid phase contact mode is formed, the capacity is smaller than that of a gas phase-solid phase contact mode. Therefore, not only can the reaction apparatus be made compact, but also the continuous replenishment and control of the liquid organometallic compound becomes easy, and a good reaction state can be maintained for a long time. In addition,
The liquid organometallic compound may be supported on a carrier such as activated carbon, alumina, or silica-alumina as appropriate to control the optimum amount as a catalyst.

Conditions such as the amount of organometallic compound to be used, reaction temperature, and contact time in the present invention vary depending on the type of organometallic compound used and the reaction form, and cannot be determined unconditionally. Generally, the organometallic compound may be used in a ratio of 1/500 to 1/2000 (by weight) to the halogen silane. The reaction temperature is generally 25 to 350°C, particularly preferably 50 to 120°C in terms of reactivity and energy economy. In addition, the contact time is generally 0.1 to 60 seconds,
In particular, 1 to 20 seconds is sufficient.

The target low-halogenated silane or monosilane can be separated from the reaction product obtained by the present invention by appropriately refluxing the other reaction products using a cooler or the like. This can be easily achieved under favorable conditions such as distillation by utilizing the difference in boiling point between the product and the organometallic compound.

Examples will be shown below, but the present invention is not limited thereto.

Example 1 (Ph ₃ P) 7.0 g of ₂ PdCl ₂ and 7.9 g of Ph ₃ P were dissolved in ethanol, and an ethanol solution of hydrazine hydrate was added and reacted (Ph ₃ P) ₄ Pd crystals were Obtained. Then, the obtained (Ph ₃ P) ₄ Pd was washed,
After drying, it was dissolved in benzene, and 40 g of activated carbon was immersed in the benzene solution and subjected to vacuum distillation.

The above (Ph ₃ P) ₄ Pd-containing activated carbon was packed in a stainless steel reactor, and dichlorosilane was heated at 80°C.
It was supplied continuously at a flow rate of 2.53/mm. As a result, a product containing 31.6 mol% of monosilane and 20.1 mol% of monochlorosilane was obtained.

Example 2 The same procedure as in Example 1 was carried out except that trichlorosilane was supplied at a flow rate of 1.86/mm instead of dichlorosilane. As a result, monosilane
A product containing 15.6 mol%, monochlorosilane 17.7 mol% and dichlorosilane 29.3 mol% was obtained.

Example 3 In a benzene solution in which 2.1 g of Ph ₄ (CO) ₁₆ was dissolved, 28.4 g of ion exchange resin Amberlite A-21 (manufactured by Rohm and Haas) having an N,N'-dimethylbenzylamine group was immersed. Processed. After removing the solvent, the above ion exchange resin was packed into a Stellence reactor, kept at 60℃, and dichlorosilane was added.
It was supplied at a flow rate of 0.78/mm. As a result, 33.6 mol% monosilane and 21.9 mol% monochlorosilane
% product was obtained.

Example 4 In Example 3, instead of Rh(CO) ₁₆
The same procedure was carried out except that 3.1 g of K ₂ PdCl ₄ was used.
As a result, 30.2 mol% of monosilane and 22.1 mol% of monochlorosilane were obtained.

Example 5 The same procedure as in Example 4 was carried out except that trichlorosilane was supplied at a flow rate of 0.50/mm instead of dichlorosilane. As a result, monosilane
A product containing 9.7 mol%, monochlorosilane 12.9 mol%, and dichlorosilane 20.6 mol% was obtained.

Example 6 33 g of polystyrene resin crosslinked with divinylbenzene was immersed in a solution of 3.1 g of PuCl ₃ dissolved in ethylene glycol, and ethylene glycol was removed by vacuum distillation.

After the polystyrene resin on which RuCl ₃ was immobilized was filled into a stainless steel reactor maintained at a temperature of 60° C., dichlorosilane was supplied at a flow rate of 1.2/mm. As a result, monosilane 28.3mol%,
A product containing 22.6 mol% of monochlorosilane was obtained.

Claims (1)

[Claims] 1. A method for producing a low-halogenated silane or monosilane, which comprises contacting a halogenated silane with an organometallic compound in which a metal or metal salt is bonded to a hydrocarbon compound, an organic nitrogen-containing compound, or an organic phosphorus-containing compound.