JP2008150273A - Apparatus for producing trichlorosilane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing trichlorosilane where, even in the case a heat element lies in a high temperature, mechanical strength is maintained, further, the generation of impurities is prevented, and further, increase in cost of members can be suppressed. <P>SOLUTION: The apparatus comprises a reactor 1 formed of quartz, a heating mechanism 2 for heating the reactor 1, and a gas spray mechanism 3 for spraying a supply gas containing tetrachlorosilane and hydrogen against the reactor 1. Namely, even in the case the reactor 1 lies in a high temperature of 800 to 1,400°C, the invention provides high mechanical strength, and further, it can be formed at high purity. Further, the phenomenon, that the reactor 1 is reacted with gas components in a feed gas and a reaction product gas, so as to produce impurities, does not occur, and trichlorosilane with high purity can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for producing trichlorosilane that converts tetrachlorosilane to trichlorosilane.

Trichlorosilane (SiHCl ₃ ) used as a raw material for producing high-purity silicon (Si: silicon) is produced by reacting tetrachlorosilane (SiCl ₄ : silicon tetrachloride) with hydrogen and converting it. Can do.

  That is, silicon is generated by the reduction reaction and thermal decomposition reaction of trichlorosilane according to the following reaction formulas (1) and (2), and trichlorosilane is generated by the conversion reaction according to the following reaction formula (3).

SiHCl ₃ + H ₂ → Si + 3HCl (1)
4SiHCl ₃ → Si + 3SiCl ₄ + 2H ₂ (2)
SiCl ₄ + H ₂ → SiHCl ₃ + HCl (3)
Various methods for producing this trichlorosilane have been proposed. For example, in Patent Document 1, a supply gas containing tetrachlorosilane and hydrogen is sprayed on a heating element formed of graphite, silicon, or silicon carbide. A technique for converting to trichlorosilane is disclosed. This production technique has an advantage that the generated trichlorosilane is immediately removed from the heating element, so that precipitation from trichlorosilane to silicon does not occur even in a temperature range of 1100 ° C. or higher.
JP-A-53-97996

  The following problems remain in the conventional technology.

That is, in the technique of Patent Document 1, a reaction gas is obtained by blowing a supply gas to a heating element formed of graphite, silicon, or silicon carbide. However, when a heating element is configured using graphite or silicon, Therefore, since the mechanical strength is low and the mechanical strength is greatly lowered at a high temperature by heating, 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 generate methane, methylchlorosilane, silicon carbide, and the like as impurities. There was an inconvenience. Further, when the heating element is composed of silicon carbide, sintered silicon carbide or pure silicon carbide with crystal growth is used, but the former is usually manufactured using boron as a sintering aid. In addition to the upper limit of ° C., hydrogen in the supply gas reacts with boron contained in silicon carbide at high temperatures to become BH _{3 and} become brittle. In the latter case, there is no influence of boron, but there is a problem that it is very expensive and the member cost becomes too high.

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

  The present invention employs the following configuration in order to solve the above problems. That is, the trichlorosilane production apparatus of the present invention comprises 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. It is characterized by having. That is, in this trichlorosilane manufacturing apparatus, since the reactor to which the supply gas is blown is formed of quartz, the reactor has high mechanical strength and high purity not only at room temperature but also at a high temperature of 800 to 1400 ° C. Can be formed. In addition, the reactor does not react with gas components in the supply gas and the reaction product gas to produce impurities, and thus high purity trichlorosilane can be obtained. In addition, since quartz is less expensive than Pure silicon carband, it is possible to suppress an increase in member cost.

  In the trichlorosilane production apparatus of the present invention, the reactor has an arc-shaped concave surface, and the gas blowing mechanism includes an injection nozzle that injects the supply gas toward the arc-shaped concave surface in the reactor. It is characterized by being. That is, in this trichlorosilane production apparatus, since the supply gas is injected from the injection nozzle toward the arc-shaped concave surface in the reactor, the supply gas injected and collided with the reactor flows along the arc of the arc-shaped concave surface, The conversion reaction can be performed more efficiently 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.

  Furthermore, in the trichlorosilane production apparatus of the present invention, the 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. It has a gas recovery mechanism that leads to the outside from the gas outlet. That is, in this trichlorosilane production apparatus, the reaction product gas is led out to the outside from the gas outlet port arranged inside the peripheral edge of the reactor, so that it is generated by colliding with the arc-shaped concave surface in the reactor. It is possible to efficiently recover the reaction product gas that flows back along.

  In addition, the trichlorosilane production apparatus of the present invention includes a support member that supports the outer surface of the reactor so as to cover it. That is, in this trichlorosilane production apparatus, since the support member supports the outer surface of the reactor, the reactor is supported by the support member from the surroundings even if the reactor softens at high temperatures. It is possible to prevent changes in the shape and the like.

  The present invention has the following effects.

  That is, according to the trichlorosilane production apparatus according to the present invention, the reactor for blowing the supply gas is made of quartz, so that the reactor has high mechanical strength not only at room temperature but also at a reaction temperature of 800 to 1400 ° C. In addition, high purity trichlorosilane can be obtained without forming impurities while being able to be formed with high purity.

  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 this embodiment includes a reactor 1 having an arcuate concave surface 1 a made of quartz, a heating mechanism 2 for heating the reactor 1, tetrachlorosilane, and hydrogen. A gas spraying mechanism 3 for spraying the supply gas containing the reactor 1 to the reactor 1, and a gas disposed inside the peripheral portion of the reactor 1 with the reaction product gas containing trichlorosilane and hydrogen chloride generated from the supply gas in the reactor 1. A gas recovery mechanism 5 that leads out from the outlet 4 is provided.

  In the case of the illustrated example, the reactor 1 uses a crucible made of quartz used for pulling and generating single crystal silicon, and is arranged with its arcuate concave surface 1a facing upward, and a cylindrical inner surface continuous from the arcuate concave surface 1a. 1b is formed in the upper part.

  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 injects the supply gas toward the arcuate concave surface 1a 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 the outer cylinder member 7 is provided inside the cylindrical inner surface 1 b at the upper part of the reactor 1. Further, it is fixed via a ring-shaped closing member 11. And between the injection nozzle 6 and the outer cylinder member 7, a reaction product gas outlet channel 8 is formed, and the lower end opening serves as the gas outlet 4. That is, the injection nozzle 6 and the outer cylinder member 7 have a double pipe structure. Further, the injection nozzle 6 is arranged so that the tip protrudes from the gas outlet 4 to the inside of the reactor 1.

  The gas blowing mechanism 3 includes an injection pump P1 connected to the injection nozzle 6 and pressurizing and supplying the supply gas, and also 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 supply gas. The gas recovery mechanism 5 includes an exhaust pump P2 that is connected to the gas outlet 4 and sucks the reaction product gas. When the reaction product gas can be discharged by a pressure difference, the exhaust pump is It can be omitted.

  The periphery of the quartz reactor 1 is supported 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 a lower portion of the support body 9a.

  The heating mechanism 2 includes a heater unit 2a that is a heat generating unit disposed around the reactor 1 so as to surround the reactor 1, and an electrode unit that is connected to a lower part of the heater unit 2a and allows a current to flow through the heater unit 2a. 2b and an annular bottom heater portion 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 inserted. The bottom heater unit 10 is also connected with an electrode unit (not shown).

  Further, the heating mechanism 2 performs heating control so that the reactor 1 has a temperature in the range of 800 ° C to 1400 ° C. In addition, if the reactor 1 is set to 1200 degreeC or more, a conversion rate will improve. Further, disilanes may be introduced into the supply gas and the silanes may be taken out.

  In this trichlorosilane manufacturing apparatus, when the supply gas is blown from the injection nozzle 6 onto the arcuate concave surface 1a of the reactor 1, the supply gas colliding with the reactor 1 heated to a high temperature is converted and a reaction product gas is generated. Is done. This reaction product gas flows along the arc of the arc-shaped concave surface 1a of the reactor 1 to the upper cylindrical inner surface 1b, is led out from the gas outlet 4 and is recovered. In the figure, the direction of gas flow is indicated by arrows.

  Thus, in this embodiment, since the reactor 1 to which the supply gas can be blown is formed of quartz, the reactor 1 has high mechanical strength not only at room temperature but also at a high temperature of 800 to 1400 ° C. At the same time, it can be formed with high purity. Moreover, the reactor 1 does not react with the gas components in the supply gas and the reaction product gas to produce impurities, and thus high purity trichlorosilane can be obtained. Furthermore, since quartz is less expensive than pure silicon carbide or the like, an increase in member cost can be suppressed.

  Further, since the supply gas is injected from the injection nozzle 6 toward the arcuate concave surface 1a in the reactor 1, the supply gas that has been injected and collided with the arcuate concave surface 1a of the reactor 1 follows the arc of the arcuate concave surface 1a. The conversion reaction can be performed more efficiently by the flow and the heating effect from the arcuate concave surface 1a.

  Further, since the reaction product gas is led out to the outside from the gas outlet 4 disposed inside the peripheral edge of the reactor 1, the reaction product gas is generated by colliding with the arc-shaped concave surface 1a of the reactor 1 and is formed into a cylindrical inner surface from the arc-shaped concave surface 1a. It is possible to efficiently recover the reaction product gas that flows back along 1b.

  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 change or the like of the reactor 1 can be prevented. Can be prevented.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the reactor 1 is heated by radiant heat from the heater unit 2a as the heating mechanism 2, but the reactor 1 may be heated by other methods such as high-frequency induction heating.

  In addition, the reactor 1 has a configuration in which the cylindrical inner surface 1b is continuously formed from the arc-shaped concave surface 1a. However, at least the surface to which the supply gas is sprayed may be an arc-shaped concave surface, and there is no cylindrical inner surface. However, the gas that has collided with the arcuate concave surface can flow smoothly 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.

  Further, in order to facilitate the flow of gas from the cylindrical inner surface of the reactor to the outlet channel 8, the ring-shaped closing member may be formed in a tapered plate shape, an arc plate shape, or the like continuous from the cylindrical inner surface. .

It is a simplified sectional view showing one embodiment of a trichlorosilane manufacturing device concerning the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 1a ... Arc-shaped concave surface, 1b ... 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

Claims (4)

A reactor formed of quartz;
A heating mechanism for heating the reactor;
An apparatus for producing trichlorosilane, comprising: a gas blowing mechanism for blowing a supply gas containing tetrachlorosilane and hydrogen to the reactor. In the trichlorosilane manufacturing apparatus according to claim 1,
The reactor has an arcuate concave surface;
The apparatus for producing trichlorosilane, wherein the gas blowing mechanism includes an injection nozzle for injecting the supply gas toward the arcuate concave surface in the reactor. In the trichlorosilane manufacturing apparatus according to claim 2,
A gas recovery mechanism for deriving a reaction product gas containing trichlorosilane and hydrogen chloride generated from the supply gas in the reactor to the outside from a gas outlet port disposed inside a peripheral edge of the arcuate concave surface in the reactor. An apparatus for producing trichlorosilane, comprising: In the trichlorosilane manufacturing apparatus according to claim 2 or 3,
An apparatus for producing trichlorosilane, comprising a support member that supports the outer surface of the reactor so as to cover the outer surface.

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