WO2008062629A1

WO2008062629A1 - Apparatus for producing trichlorosilane

Info

Publication number: WO2008062629A1
Application number: PCT/JP2007/070735
Authority: WO
Inventors: Toshiyuki Ishii
Original assignee: Mitsubishi Materials Corporation
Priority date: 2006-11-21
Filing date: 2007-10-24
Publication date: 2008-05-29

Abstract

This invention provides an apparatus for producing trichlorosilane, comprising a reactor formed of quartz, a heating mechanism for heating the reactor, and a gas spray mechanism for spraying a supply gas containing tetrachlorosilane and hydrogen against the reactor. The reactor has an arc-shaped recessed face, and the gas spray mechanism may be provided with a jet nozzle for jetting the supply gas toward the arc-shaped recessed face in the reactor.

Description

Technical field

[0001] The present invention relates to conversion of tetrachlorosilane to trichlorosilane.

About.

This application is superior to Japanese Patent Application No. 2006-314897 filed on November 21, 2006 and Japanese Patent Application No. 2007-249626 filed on September 26, 2007.

Light

Insist on priorities and use the contents here.

Background art

book

[0002] Trichlorosilane used as a raw material for producing high-purity silicon (Si: silicon)

(SiHCl 3) is converted by reacting tetrachlorosilane (SiCl: silicon tetrachloride) with hydrogen.

3 4

And manufacturing.

[0003] That is, silicon is produced by the reduction reaction and thermal decomposition reaction of trichlorosilane by the following reaction formulas (1) and (2), and trichlorosilane is produced by the conversion reaction by the following reaction formula (3). It is.

[0004] SiHCl + H → Si + 3HC1 (1)

3 2

4SiHCl → Si + 3SiCl + 2H (2)

3 4 2…

SiCl + H → SiHCl + HC1 (3)

4 2 3

Various methods have been proposed as methods for producing this trichlorosilane. For example, Patent Document 1 discloses a supply gas containing tetrachlorosilane and hydrogen in a heating element formed of graphite, silicon, or silicon carbide. A technique for spraying and converting to trichlorosilane is disclosed. This production technology has the advantage that the generated trichlorosilane is immediately removed from the heating element, so that no precipitation of trichlorosilane into silicon occurs even in the temperature range above 1100 ° C.

However, the following problems remain in the above conventional technique.

In the technique disclosed in Patent Document 1, a reaction gas is obtained by spraying a supply gas to a heating element formed of graphite, silicon, or silicon carbide. When a heating element is configured using, the mechanical strength is low at room temperature, and the mechanical strength is greatly reduced at a high temperature by heating. Therefore, a heating element with higher strength is desired. In addition, when a heating element formed of graphite is used, hydrogen, chlorosilane, and hydrogen chloride in the supply gas and reaction product gas react with each other to produce methane, methylchlorosilane, silicon carbide, and the like. There was an inconvenience of becoming an impurity. In addition, when the heating element is composed of silicon carbide, the force to use sintered silicon carbide or crystal-grown Pure silicon carbide. The former is usually made using boron as a sintering aid. In addition to the upper limit of 1300 ° C, hydrogen in the supply gas reacts with boron contained in silicon carbide at high temperatures to become BH, which makes it brittle. In the latter case

Three

Although there was no influence of boron, there was a problem that it was very expensive and the member cost was too high.

Patent Document 1: JP-A 53-97996

Disclosure of the invention

Problems to be solved by the invention

[0006] The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a trichlorosilane production apparatus that has high mechanical strength, prevents generation of impurities, and can suppress increase in member cost. To do.

Means for solving the problem

[0007] The present invention employs the following configuration in order to solve the above problems.

An apparatus for producing trichlorosilane according to the present invention includes a reactor formed of quartz, a heating mechanism for heating the reactor, and a gas blowing mechanism for blowing a supply gas containing tetrachlorosilane and hydrogen to the reactor. /!

In this trichlorosilane production system, the reactor to which the feed gas can be blown is made of quartz, so the reactor has high mechanical strength and high purity not only at room temperature but also at high temperatures of 800 ~; 1400 ° C. Can be formed. Further, it is possible to obtain trichlorosilane having a high purity without causing the reactor to react with gas components in the supply gas and the reaction product gas to generate impurities. In addition, quartz is less expensive than pure silicon carband, so it is possible to suppress the increase in material costs. [0008] Further, in the trichlorosilane production apparatus of the present invention, the reactor has an arc-shaped concave surface, and the gas blowing mechanism injects the supply gas toward the arc-shaped concave surface in the reactor. An injection nozzle may be provided. In this case, in this trichlorosilane production apparatus, the supply gas is injected from the injection nozzle toward the arc-shaped concave surface of the reactor, so that the supply gas injected and collided with the reactor flows along the arc of the arc-shaped concave surface. The conversion reaction can be more efficiently performed by the heating effect from the arcuate concave surface. As a reactor having an arcuate concave surface, a quartz crucible used for pulling and generating single crystal silicon can be suitably used.

[0009] In the trichlorosilane production apparatus of the present invention, a reaction product gas containing trichlorosilane and hydrogen chloride generated from the supply gas in the reactor is disposed inside the peripheral edge of the arcuate concave surface in the reactor. In addition, a gas recovery mechanism that leads to the outside from the gas outlet may be provided. In this case, in this trichlorosilane production apparatus, the reaction product gas is led out to the outside from the gas outlet port arranged on the inner periphery of the reactor, so that it is generated by colliding with the arcuate concave surface in the reactor. The reaction product gas that flows back along the arc can be efficiently recovered.

[0010] The trichlorosilane production apparatus of the present invention may include a support member that supports the outer surface of the reactor. In this case, in this trichlorosilane production apparatus, since the support member covers the outer surface of the reactor, the support member is supported from the surroundings even if the reactor softens at high temperatures. Changes in the shape of the reactor can be prevented.

The invention's effect

[0011] According to the present invention, the following effects are obtained.

According to the trichlorosilane production apparatus according to the present invention, since the reactor for blowing the supply gas is formed of stone, the reactor is not only at room temperature but also at a reaction temperature of 800 to 1400 ° C. It is possible to obtain trichlorosilane having high strength and high purity, which can form a reactor with high purity quartz and does not generate impurities.

Brief Description of Drawings

FIG. 1 is a simplified cross-sectional view showing an embodiment of a trichlorosilane production apparatus according to the present invention. FIG.

Explanation of symbols

[0013] 1 · · · Reactor, la… arc-shaped concave surface, lb… cylindrical inner surface, 2 ··· Heating mechanism, 3 ··· Gas blowing mechanism, 4 ··· Gas outlet, 5 ··· Gas Recovery mechanism 6 · · · Injection nozzle 8 · · · Outlet flow path 9 · Carbon support member 11 · · · Ring-shaped closing member 12 · · · Preheating mechanism

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a trichlorosilane production apparatus according to the present invention will be described with reference to FIG.

As shown in FIG. 1, the trichlorosilane production apparatus of the present embodiment includes a reactor 1 having an arc-shaped concave surface la formed of quartz, a heating mechanism 2 for heating the reactor 1, a tetrachlorosilane and hydrogen. A gas spray mechanism 3 for spraying a feed gas containing 1 to the reactor 1 and a reaction product gas containing trichlorosilane and hydrogen chloride generated from the feed gas in the reactor 1 are arranged inside the periphery of the reactor 1. And a gas recovery mechanism 5 that leads out from the gas outlet 4.

[0015] In the case of the illustrated example, the reactor 1 uses a quartz crucible used for pulling and generating single crystal silicon, and is arranged with its arcuate concave surface la facing upward, and the arcuate concave surface la force A continuous cylindrical inner surface lb is formed at the top.

The gas blowing mechanism 3 includes an injection nozzle 6 that is arranged on the central axis of the upper part of the reactor 1 and that injects the supply gas toward the arcuate concave surface la of the reactor 1. Further, an outer cylinder member 7 arranged coaxially with the injection nozzle 6 is provided on the outer side of the injection nozzle 6, and this outer cylinder member 7 is provided on the inner side of the cylindrical inner surface lb above the reactor 1. Further, it is fixed via a ring-shaped closing member 11. A space between the injection nozzle 6 and the outer cylinder member 7 serves as a reaction product gas outlet channel 8, and a lower end opening serves as a gas outlet 4. That is, the injection nozzle 6 and the outer cylinder member 7 have a double pipe structure. The injection nozzle 6 is arranged so that the tip protrudes from the gas outlet 4 to the inside of the reactor 1.

[0017] The gas blowing mechanism 3 includes an injection pump P1 connected to the injection nozzle 6 and pressurizing and supplying the supply gas, and includes a preheating mechanism 12 that heats the supply gas before supplying it to the reactor 1. The injection pump P1 is connected to a supply source (not shown) of the supply gas. Yes. The gas recovery mechanism 5 is connected to the gas outlet 4 and is equipped with an exhaust pump P2 that sucks the reaction product gas S. If the reaction product gas can be discharged by a pressure difference, the gas recovery mechanism 5 The pump can be omitted.

[0018] The quartz reactor 1 is supported at its periphery by a carbon support member 9. The carbon support member 9 includes a support body 9a that covers the periphery of the reactor 1, and a support column 9b that is provided at the lower portion of the support body 9a.

[0019] The heating mechanism 2 is arranged around the reactor 1 so as to surround the reactor 1, and is connected to the lower part of the heater unit 2a that is a heat generating unit and flows through the heater unit 2a. And an annular bottom heater section 10 disposed below the reactor 1. The electrode portion 2b is connected to a power source (not shown). The bottom heater portion 10 is installed below the support portion main body 9a in a state where the support column portion 9b of the carbon support member 9 is passed through. The bottom heater unit 10 is also connected to an electrode unit (not shown).

[0020] In addition, the heating mechanism 2 performs calorie heat control so that the reactor 1 has a temperature in the range of 800 ° C to 1400 ° C. If reactor 1 is set to 1200 ° C or higher, the conversion rate is improved. Further, disilanes may be introduced into the supply gas and the silanes may be taken out.

[0021] In this trichlorosilane production apparatus, when the supply gas is blown from the injection nozzle 6 onto the arc-shaped concave surface la of the reactor 1, the supply gas colliding with the reactor 1 heated to a high temperature is converted and reacted. Gas is generated. This reaction product gas flows to the upper cylindrical inner surface lb along the arc of the arcuate concave surface 1a of the reactor 1, and is led out from the gas outlet 4 to be collected. In the figure, the direction of gas flow is indicated by arrows.

[0022] Thus, in this embodiment, since the reactor 1 to which the supply gas is blown is formed of quartz, the reactor 1 has a high mechanical strength not only at room temperature but also at a high temperature of 800 to 1400 ° C. In addition, the reactor 1 can be formed of high-purity quartz. Further, the reactor 1 does not react with the gas components in the supply gas and the reaction product gas to generate impurities, and thus high purity trichlorosilane can be obtained. Furthermore, since quartz is less expensive than pure silicon carbide, it is possible to suppress an increase in material costs.

[0023] Further, since the supply gas is injected from the injection nozzle 6 toward the arc-shaped concave surface la in the reactor 1, the supply gas that has been injected and collided with the arc-shaped concave surface 1a of the reactor 1 is arc-shaped concave surface 1 a The force S is applied to make the conversion reaction more efficiently by the heating effect from the arcuate concave surface la.

[0024] Further, since the reaction product gas is led out from the gas outlet 4 disposed inside the peripheral edge of the reactor 1, it is generated by colliding with the arc-shaped concave surface la of the reactor 1 and from the arc-shaped concave surface la. The reaction product gas that flows back upward along the cylindrical inner surface lb can be efficiently recovered.

[0025] Further, since the periphery of the reactor 1 is supported by the carbon support member 9, even if the reactor 1 is softened at a high temperature, the carbon support member 9 supports from the periphery, so that the shape of the reactor 1 Changes can be prevented.

[0026] It should be noted that the technical scope of the present invention is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the present invention.

[0027] For example, in the above embodiment, the heating mechanism 2 may be a power that heats the reactor 1 with radiant heat from the heater 2a. The reactor 1 may be heated by other methods such as high-frequency induction heating.

[0028] Further, the reactor 1 has a configuration in which the cylindrical inner surface lb is continuously formed from the arc-shaped concave surface la, but at least the surface on which the supply gas is blown may be a circular arc-shaped concave surface. Even if there is no inner surface, the force S can smoothly flow the gas that collides with the arc-shaped concave surface along the surface of the reactor. In this case, the arcuate concave surface may not be an arc having the same curvature, but may be a series of arcs having a plurality of curvatures. An arc-shaped concave surface is suitable for recovering the reaction product gas, but in the present invention, a surface shape other than the arc-shaped concave surface is not excluded.

[0029] Further, in order to facilitate the flow of gas from the cylindrical inner surface of the reactor to the outlet flow path 8, the ring-shaped closing member is formed in a tapered plate shape, an arc plate shape, or the like continuous from the cylindrical inner surface. You can do it.

Industrial applicability

[0030] According to the trichlorosilane production apparatus of the present invention, since the reactor for blowing the supply gas is formed of quartz, the reactor has a high mechanical strength even at a reaction temperature of 800 to 1400 ° C, The reactor can be formed of high purity quartz. Further, high purity trichlorosilane can be obtained without generating impurities. For this reason, high purity silicon is produced. Therefore, it can be suitably used in the production process of trichlorosilane used as a raw material for the purpose.

Claims

The scope of the claims

[1] a reactor formed of quartz;

A heating mechanism for heating the reactor;

An apparatus for producing trichlorosilane, comprising: a gas spraying mechanism for spraying a supply gas containing tetrachlorosilane and hydrogen to the reactor.

[2] The reactor has an arcuate concave surface,

2. The apparatus for producing trichlorosilane according to claim 1, wherein the gas blowing mechanism includes an injection nozzle that injects the supply gas toward the arcuate concave surface in the reactor.

[3] A reaction product gas containing trichlorosilane and hydrogen chloride generated from the supply gas in the reactor is led out from a gas outlet disposed inside the peripheral edge of the arcuate concave surface in the reactor. The trichlorosilane production apparatus according to claim 2, further comprising a gas recovery mechanism.

4. The apparatus for producing trichlorosilane according to claim 2, further comprising a support member that supports the outer surface of the reactor so as to cover the outer surface.

[5] The trichlorosilane production apparatus according to [3], further comprising a support member that supports the outer surface of the reactor so as to cover the outer surface.