JP4890044B2 - Chlorosilane reactor - Google Patents

Description

  The present invention relates to a novel reaction apparatus having a reaction part heated to a high temperature by a high-frequency induction heating coil and performing a reaction between chlorosilanes and hydrogen, and in particular, by a magnetic flux from the high-frequency induction heating coil. The present invention relates to an improvement in technology for preventing a member heated to a high temperature from being corroded and quickly deteriorated by being heated to a high temperature, and preventing the corroded material from volatilizing and contaminating a raw material gas.

  Conventionally, various methods for producing silicon used as a raw material for semiconductors, photovoltaic power generation batteries and the like are known, and some of these methods have already been industrially implemented.

For example, one of them is a method called the Siemens method. In this method, a silicon rod heated to a silicon deposition temperature by energization is placed inside a bell jar, and trichlorosilane (SiHCl ₃ ) or monosilane ( SiH ₄ ) is brought into contact with a reducing gas such as hydrogen to deposit silicon.

  In this method, high-purity silicon is obtained, and it is industrially implemented as a general method. However, in order to deposit silicon in a batch system, it is necessary to install a silicon rod as a seed, to heat and deposit the silicon rod. It is necessary to repeat a series of processes such as cooling, taking out, and cleaning the bell jar for each batch, which requires complicated operations.

  On the other hand, as a method capable of continuously producing polycrystalline silicon, a method using an apparatus having a structure as shown in FIG. 1 has been proposed (Patent Documents 1 and 2). This silicon production apparatus is installed in a closed vessel 1 on a reaction tube 11 based on carbon and on the upper side of the reaction tube 11, and chlorosilanes, or chlorosilanes and hydrogen are introduced into the reaction tube 11. A source gas supply port 6 to be supplied and a high-frequency induction heating coil 15 installed on the outer periphery of the reaction tube 11 are provided. Although not shown, a heat insulating material (heat insulating member) is installed between the reaction tube 11 and the high frequency induction heating coil 15 as necessary.

With the apparatus shown in the figure, the reaction tube 11 is heated above the melting point of silicon by electromagnetic waves from the high frequency induction heating coil 15, and chlorosilanes supplied from the source gas supply port 6 are brought into contact with the inner surface of the reaction tube 11 to form liquid silicon. The silicon product can be recovered in the cooling recovery chamber 21 by being deposited from the lower end portion 11a. When setting the temperature of the reaction tube 11 below the melting point of silicon, the temperature of the reaction tube 11 is occasionally raised to the melting point of silicon or higher so that a part or all of the precipitate is melted and dropped. it can.

  It has been found that if silicon is deposited in a region other than the inner surface of the reaction tube 11 in the sealed container 1 of such a silicon production apparatus, it becomes a factor such as operation hindrance in long-term use. As a means for suppressing this, it is necessary to prevent the silicon deposition from occurring in a region, for example, a gap between the reaction tube 11 and the source gas supply tube 5, or an outer peripheral side region of the reaction tube 11 and a lower end portion 11 a of the reaction tube 11. It has been found that it is effective to provide a seal gas supply port and supply a seal gas such as hydrogen to fill the seal gas atmosphere.

In addition, as a technique for effectively preventing silicon precipitation at the lower end portion 11a of the reaction tube 11 and the periphery thereof, the present applicant has made a technique in which the periphery of the lower end portion 11a of the reaction tube 11 is structured as shown in FIG. And has already filed a patent application. In this technique, the lower end 1 of the reaction tube 11
A first gas supply port 31 that forms an annular slit and supplies a sealing gas and / or an etching gas toward the lower end portion 11a is provided on the outer peripheral side in the vicinity of 1a. Further, preferably, a seal gas and / or an etching gas is applied toward a wall around the outside of the first gas supply port 31 in a member forming the first gas supply port 31 at a position separated from the first gas supply port 31. A second gas supply port 33 for supplying is provided.

  By adopting such a structure, for example, a heat retaining member wound around the reaction tube 11, an outer peripheral side region of the reaction tube 11 in which a heating device for heating the lower end portion 11 a of the reaction tube 11 or the like is installed, or the reaction tube 11 The silicon deposition on the lower end 11a can be suppressed with a small amount of supply gas.

  Further, the wall surface of the member forming the first gas supply port 31 is heated to a high temperature by radiant heat from the reaction tube 11 or the like. As a result, silicon tends to be precipitated by the source gas from the inside of the reaction tube 11. By providing the second gas supply port 33 at a position separated from the first gas supply port 31, the seal gas or the like is supplied from the second gas supply port 33 toward the outer peripheral wall surface of the first gas supply port 31 in the member. Therefore, silicon deposition on the wall surface of the member forming the first gas supply port 31 can be suppressed. As a result, the shape of the first gas supply port 31 is maintained for a long time, and the supply of seal gas and the like from the first gas supply port 31 to the lower end portion 11a of the reaction tube 11 is not hindered during that time.

1 is also used as a reaction apparatus for bringing chlorosilanes and hydrogen into contact with the inner surface of the reaction tube 11 to cause a hydrogen reduction reaction to produce the desired chlorosilanes. For example, an apparatus similar to FIG. 1 is used to reduce silicon tetrachloride to trichlorosilane for the purpose of recovering a raw material gas for producing polycrystalline silicon.
JP 2003-2627 A JP 2002-29726 A

  However, according to the present inventors' confirmation, members disposed around the reaction tube 11, particularly around the lower end portion 11a, are corrosive gases such as hydrogen, hydrogen / hydrogen chloride, inert gas / hydrogen chloride. When exposed to a high temperature atmosphere and heated to a high temperature, it corrodes and deteriorates quickly, or the corroded material volatilizes and contaminates the source gas, resulting in contamination of the manufactured silicon. The problem occurs. Such a phenomenon becomes prominent particularly when heated to a temperature of 1200 ° C. or higher.

  In addition, the above members require heat resistance in order to receive strong radiant heat from the reaction tube, and are often made of carbon or the like having high chemical stability at high temperatures. Therefore, in addition to the heating by radiation, it is heated directly by the magnetic flux from the high frequency induction heating coil and becomes an abnormally high temperature. did.

Further, the above-mentioned member made of carbon or the like shields the magnetic flux when installed between the high frequency induction heating coil and the reaction tube, and causes power loss or local temperature decrease of the reaction tube.
Accordingly, an object of the present invention is to be exposed to a corrosive gas atmosphere as described above in a chlorosilane-hydrogen reactor having a reaction portion heated to 1000 ° C. or higher by a high-frequency induction heating coil, and high-frequency induction heating. To provide a reaction apparatus in which, when a member is arranged at a position that is affected by magnetic flux from a coil and is in a temperature range of 1000 ° C. or higher, the deterioration of the member is small and the contamination of the product is reduced. It is in.

  As a result of further research based on the above knowledge, the present inventors have effectively prevented the deterioration of the member in the environment by using specific mullite or silicon nitride as the material of the member, which is necessary. It has been found that the shape, strength, etc. for exhibiting the function can be maintained for a long period of time, and that contamination of products such as silicon and chlorosilane produced in the reaction apparatus can be suppressed, and the present invention has been completed.

The reaction apparatus of the present invention is a reaction apparatus for reacting chlorosilanes with hydrogen having a reaction part heated to 1000 ° C. or higher by a high-frequency induction heating coil,
A temperature region of 1000 ° C. or more and a sintered member which is disposed in a position affected by the magnetic flux from the high-frequency induction heating coil, mullite (composition formula _{2SiO 2 · 3Al 2 O 3)} , or, an oxide It is formed of silicon nitride (composition formula Si ₃ N ₄ ) as an auxiliary agent.

  In a preferred embodiment of the above invention, the reaction apparatus is formed using carbon as a base material, and is provided around a reaction tube that is supplied with chlorosilanes and hydrogen from the upper side to the inside of the tube, and is provided outside the reaction tube. And a high frequency induction heating coil. In this aspect, the member is disposed on the outer peripheral side of the reaction tube, and is a member that forms an annular slit-shaped gas supply port that supplies a sealing gas and / or an etching gas to the lower end of the reaction tube. preferable.

  According to the present invention, a member that is used in an atmosphere of corrosive gas at a temperature of 1000 ° C. or higher, particularly 1200 ° C. or higher and used in a range where magnetic flux from a high frequency induction heating coil acts, for example, a high frequency induction heating coil Since the material having the specific composition disclosed in the present invention is used as the material of the member disposed inside the member, the corrosion resistance of the member is high, and the replacement frequency of the member can be extremely reduced. Furthermore, contaminants generated from the member are also suppressed, and as a result, contamination of the manufactured silicon and the like is suppressed.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The reaction apparatus of the present invention is a reaction apparatus for reacting chlorosilanes with hydrogen having a reaction part heated to 1000 ° C. or higher by a high-frequency induction heating coil.

  The reaction apparatus of the present invention includes a silicon production apparatus for depositing polycrystalline silicon by bringing chlorosilanes and hydrogen into contact with the inner surface of a reaction tube heated by a high-frequency induction heating coil provided around the reaction tube. included.

  Further, in the reaction apparatus of the present invention, a hydrogen reduction reaction is caused by bringing chlorosilanes and hydrogen into contact with the inner surface of the reaction tube heated by a high frequency induction heating coil provided outside the reaction tube. A hydrogen reduction reaction apparatus for recovering the reaction product gas is included. A typical example is the reduction of silicon tetrachloride to trichlorosilane by bringing silicon tetrachloride and hydrogen into contact with the inner surface of the reaction tube for the purpose of recovering the raw material gas for the production of polycrystalline silicon. Can be mentioned.

  Both the silicon production apparatus and the hydrogen reduction reaction apparatus have the same basic structure, and have a structure as shown in the embodiment of FIGS. Hereinafter, although the silicon manufacturing apparatus according to the embodiment of FIGS. 1 to 3 will be described, these descriptions are basically applied to the hydrogen reduction reaction apparatus as well.

FIG. 1 is a cross-sectional view of a silicon manufacturing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the silicon manufacturing apparatus of the present embodiment includes a cylindrical reaction tube 11 in a sealed container 1. The shape of the reaction tube 11 is typically a cylindrical shape, and the lower end portion 11a is opened downward.

As the base material of the reaction tube 11, a carbon material such as graphite that can be heated by a high-frequency induction heating coil and is resistant to a silicon melt is used.
By supplying chlorosilanes and hydrogen into the reaction tube 11 from the upper side of the reaction tube 11, polycrystalline silicon is deposited on the inner surface of the reaction tube 11 heated by the high frequency induction heating coil 15.

Examples of chlorosilanes used in the reaction include trichlorosilane (SiHCl ₃ ).
, Mention may be made of silicon tetrachloride (SiCl _4), In addition, dichlorosilane (SiH ₂ Cl _2), monochlorosilane (SiH ₃ Cl), and chlorodisilanes typified by hexachlorodisilane (Si ₂ Cl ₆₎ Also, chlorotrisilanes represented by octachlorotrisilane (Si ₃ Cl ₈ ) can be preferably used. These chlorosilanes may be used alone or in combination of two or more.

  By using trichlorosilane or silicon tetrachloride as the main ingredient as the raw material chlorosilane, it is possible to reduce the generation of silicon fine powder and ignitable high-boiling silanes (polymers) that adversely affect the gas downstream area. Long-term stable operation is possible.

  Hydrogen used for the precipitation reaction together with the chlorosilanes is supplied from, for example, the source gas supply pipe 5 and the seal gas supply port 12. Alternatively, it is also possible to connect a supply pipe separate from the supply pipe for chlorosilanes to an appropriate position of the reaction pipe 11 and supply hydrogen from this supply pipe.

  Silicon is deposited by bringing the inner surface of the reaction tube 11 to a temperature below the melting point at which silicon can be deposited, and then heating the inner surface of the reaction tube 11 to a temperature equal to or higher than the melting point to melt the silicon and drop it downward. 1 may be provided instead of the source gas supply port 6 inside the reaction tube 11 as shown in FIG. 1, but the source gas supply port may be provided above the upper surface of the reaction tube 11. In this case, hydrogen gas may be supplied from the vicinity of the upper surface of the reaction tube 11 through a separate path from the chlorosilane source gas supply port.

  The reaction tube 11 is heated by electromagnetic waves from the high-frequency induction heating coil 15 on the outer periphery thereof, and the inner surface of the reaction tube 11 is heated to a temperature not lower than the melting point of silicon or a temperature at which less silicon can be deposited.

  The high frequency induction heating coil 15 generates electromagnetic waves by energizing the coil from the power source to heat the reaction tube 11. The frequency of this electromagnetic wave is set to an appropriate value according to the material or shape of the object to be heated, such as the reaction tube 11, and is set to about several tens Hz to several tens GHz, for example.

  As described above, there are two kinds of typical methods for producing polycrystalline silicon. Of the two methods, the former method uses the electromagnetic wave from the high frequency induction heating coil 15 to change the temperature of the inner surface of the reaction tube 11. Preferably, 950 ° C. or higher, more preferably 1200 ° C. or higher, and further preferably 1300 ° C. or higher is heated to a temperature lower than the melting point at which silicon can be deposited, and the chlorosilanes supplied from the source gas supply port 6 are To deposit silicon as a solid. Thereafter, the inner surface of the reaction tube 11 is heated to a temperature equal to or higher than the melting point of silicon (approximately 1410 to 1430 ° C.), and a part or all of the precipitate is melted and dropped from the opening of the lower end portion 11a. It collects in the installed cooling recovery chamber 21.

In the latter method, the temperature of the inner surface of the reaction tube 11 is heated to the melting point of silicon or higher by electromagnetic waves from the high frequency induction heating coil 15, and chlorosilanes supplied from the source gas supply port 6 are applied to the inner surface of the reaction tube 11. The silicon is deposited in a molten state by contact, and the silicon melt is continuously dropped from the opening of the lower end portion 11a of the reaction tube 11 and recovered in the cooling recovery chamber 21 installed in the dropping direction.

  In these manufacturing methods, the silicon melt flows downward along the inner surface of the reaction tube 11, freely falls as droplets from the lower end, and solidifies during or after the fall. The silicon that has fallen into the cooling recovery chamber 21 may be a solid coolant such as silicon or carbon, a liquid coolant such as liquid silicon tetrachloride, liquid nitrogen, or the cooling recovery chamber 21 as shown in FIG. It cools with the cooling gas supplied from the cooling gas supply port 22 provided in the.

Further, the cooling recovery chamber 21 may be provided with an outlet 23 for continuously or intermittently extracting the solidified silicon, as shown in FIG. 1, if necessary.
FIG. 2A is a cross-sectional view showing the periphery of the lower end of the reaction tube of a silicon production apparatus according to another embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line AA. As shown in the figure, an annular member 32 is provided on the outer peripheral side of the reaction tube 11, and the outer region of the reaction tube 11 in which the heat retaining member 36, the high frequency induction heating coil 15, etc. are installed has an annular member 32 and a bottom plate 39. Etc., and is isolated from the space below.

The seal gas 37 is supplied to the lower end portion 11 a of the reaction tube 11 through the first gas supply port 31 formed of an annular slit formed between the inner peripheral surface of the annular member 32 and the outer peripheral surface of the reaction tube 11.
Here, the lower end portion 11a of the reaction tube 11 indicates the tube surface in the region surrounded by the broken line in FIG.

  A ring-shaped member 34 is disposed below the annular member 32. The ring-shaped member 34 is provided with a circumferential second gas supply port 33 and connected to a gas supply pipe or the like communicating with the outside. Seal gas 38 is supplied from the second gas supply port 33 of the ring-shaped member 34 toward the bottom surface of the annular member 32, thereby suppressing silicon deposition on the bottom surface of the annular member 32.

  FIG. 3 is a cross-sectional view showing the periphery of the lower end of a reaction tube of a silicon production apparatus according to another embodiment of the present invention. As shown in the figure, an annular member 32 is provided on the outer peripheral side of the reaction tube 11, and the outer region of the reaction tube 11 in which the heat retaining member 36, the high frequency induction heating coil 15 and the like are installed is formed by the annular member 32 and the like. It is isolated from the space below it.

The seal gas 37 is supplied to the lower end portion 11 a of the reaction tube 11 through the first gas supply port 31 formed of an annular slit formed between the inner peripheral surface of the annular member 32 and the outer peripheral surface of the reaction tube 11.
The annular member 32 is provided with a large number of pores 40, and the outlets of these pores 40 are arranged on the inner peripheral surface of the annular member 32 along the circumference. These pores 40 constitute a second gas supply port 33, and a wall surface around the outside of the first gas supply port 31 in the annular member 32 from the second gas supply port 33 (inner circumference on the upper side of the outlet of the pore 40). The seal gas 38 is supplied toward the surface), thereby suppressing silicon deposition on the wall surface. That is, the annular member 32 in FIG. 3 has the same function as the annular member 32 shown in FIGS. 1 and 2.

It has been confirmed that the following problems occur in the silicon manufacturing apparatus described above. That is, the members arranged around the reaction tube 11, particularly around the lower end portion 11 a, specifically, the members forming the annular member 32 and the second gas supply port 33 are induction-heated by the high-frequency induction heating coil 15. Is heated to a temperature of 1000 ° C. or higher by radiant heat from the carbon reaction tube 11 thus formed, and then hydrogen, hydrogen / hydrogen chloride, inert gas contained in the raw material gas, seal gas, etching gas, etc. / In the atmosphere of corrosive gas containing hydrogen chloride etc., the above-mentioned member heated to high temperature is corroded and deteriorates quickly, or the corroded material volatilizes and pollutes the gas. And began to contaminate the silicon. Such a phenomenon becomes prominent particularly when heated to a temperature of 1200 ° C. or higher. Such a problem can occur in the hydrogen reduction reaction apparatus as well.

  Further, the region heated to a high temperature by the radiant heat from the reaction tube 11 is affected by the magnetic flux from the high-frequency induction heating coil 15, so that the above-mentioned member is formed of a material such as carbon or silicon carbide. Then, the member itself generates abnormal heat due to induction heating, and the deterioration of other members is accelerated or significantly damaged.

  In order to solve such problems, the present inventors have intensively studied. As a result, they contacted a gas containing hydrogen and / or chloride at a temperature of 1000 ° C. or higher in a reactor for chlorosilanes, and It has been found that it is effective to form a member that requires insulation properties against magnetic flux from the high-frequency induction heating coil from mullite or silicon nitride using an oxide as a sintering aid.

  That is, mullite or the specific silicon nitride is superior in corrosion resistance under the above environment, less gas contamination or product contamination due to volatilization, and insulation performance compared to members made of other heat resistant materials. The problems that occur when the apparatus is operated under the above conditions can be effectively prevented.

  On the other hand, when, for example, silicon carbide (compositional formula SiC) is used as the material of the member, the insulation performance is low, and the member is often heated abnormally by the magnetic flux from the high frequency induction heating coil.

As materials for the above members, alumina (compositional formula Al ₂ O ₃ ), zirconia (compositional formula ZrO ₂ )
When boron nitride (composition formula BN) is used, the deterioration rate is slow and the shape (structure) is maintained for a relatively long period of time, but product contamination often occurs due to an increase in the amount of released impurities. For cordierite (compositional formula 2MgO · 2AlO ₃ · 5SiO ₂ ), calcium silicate (compositional formula CaSiO ₃ ), etc., in addition to product contamination, the shape (structure) collapses due to significant deterioration and the necessary sealing function There is a case where the decrease of the speed proceeds rapidly.

Further, when carbon (composition formula C) is used as the material of the member, for example, the member is heated by the magnetic flux from the high frequency induction heating coil, abnormally generates heat, and deterioration is promoted. In addition, the present inventors made and tested the above members using materials such as silicon (composition formula Si), magnesia (composition formula MgO), and quartz (composition formula SiO ₂ ). As shown, each was not satisfactory.

  In silicon nitride using the oxide as a sintering aid, the oxide used as the sintering aid is preferably an oxide containing aluminum, yttrium, or scandium as a main component of a metal element, specifically Includes aluminum oxide (alumina), yttrium oxide (yttria), scandium oxide, and the like. These may be used individually by 1 type and may be used in combination of multiple types. As the compounding amount of the oxide sintering aid, a known use amount is adopted without any particular limitation, but it is preferably 10% by weight or less.

  In the sealed container, the portion that contacts the corrosive gas at a temperature of 1000 ° C. or higher is mainly the periphery of the reaction tube and the inner region of the high frequency induction heating coil. Even if at least a portion thereof is disposed inside the high frequency induction heating coil, abnormal heat generation is not caused by the magnetic flux from the high frequency induction heating coil.

The “inside of the high-frequency induction heating coil” here is not limited to the inside of the coil as long as the magnetic flux of the high-frequency heating coil sufficiently extends. For example, the range below the lower end of the high-frequency induction heating coil Are also included.

Specific examples of the members arranged in the above range include the following members arranged around the lower end of the reaction tube.
(I) Gas shielding partition wall disposed on the outer periphery side of the reaction tube (ii) An annular slit-shaped gas supply disposed on the outer periphery side of the reaction tube and supplying seal gas and / or etching gas to the lower end of the reaction tube (Iii-1) Forming a ring slit-shaped first gas supply port for supplying seal gas and / or etching gas toward the lower end of the reaction tube on the outer peripheral side in the vicinity of the lower end of the reaction tube Member (iii-2) A seal gas and / or an etching gas is supplied toward the outer peripheral wall surface of the first gas supply port in the member forming the first gas supply port at a position separated from the first gas supply port The member forming the second gas supply port, that is, the member forming the first gas supply port 31 shown in FIGS. 1 to 3, for example, the annular member 32, the member forming the second gas supply port 33, or these Part of Such member for supporting the is exemplified as the member. These members may be heated to 1000 ° C. or higher mainly by radiant heat from the vicinity of the lower end portion 11a of the reaction tube 11, and in particular, the members forming the first gas supply port 31 are scaled up. Often heated to 1000 ° C. or higher. In addition, these members are exposed to an atmosphere of corrosive gas contained in source gas, seal gas, etching gas, and the like.

  In addition to the member having the function of forming the first gas supply port, the gas shielding partition wall arranged on the outer peripheral side of the reaction tube described above flows out gas that may cause silicon precipitation to the outside. A member having a function of preventing and confining inside is included.

In addition, as a specific example of the member disposed in the above range, a member constituting a support portion of the heat retaining member wound around the outer periphery of the reaction tube can be cited.
According to the present invention, a specific composition is used as a material of a member used in an atmosphere of corrosive gas at a temperature of 1000 ° C. or higher, particularly 1200 ° C. or higher, for example, a member disposed inside a high frequency induction heating coil. Because it has ceramics, it has high corrosion resistance and can be used for a long time. Further, the gas inside the reaction tube is contaminated by volatilization of the member, and as a result, the manufactured silicon or the like is not contaminated. Further, the member itself does not generate abnormal heat due to the magnetic flux generated from the high frequency induction heating coil for heating the reaction tube.

  All of the above members may be formed of the above ceramics, or only portions necessary for obtaining the effects of the present invention described above may be formed of the above ceramics. For example, the heat retaining member (reference numeral 36 in FIGS. 2 and 3) wound around the outer periphery of the reaction tube is typically formed of a low-density carbon material, but suddenly due to magnetic flux from the high-frequency induction heating coil. In order to prevent heat generation by energization, a portion of the carbon material cut in the longitudinal direction in a spiral shape, etc. is provided, and the ceramics is provided in the portion, and this gap is connected to energize the heat retaining member in the circumferential direction. Can be prevented.

  The present invention has been described above with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention.

  For example, in the preferred embodiment described above, the first gas supply port and the second gas supply port are provided, but the present invention is not provided with these, or the first gas supply port without the second gas supply port. The aspect which provides only is also included.

Examples Hereinafter, the present invention will be described with reference to more specific examples. However, the present invention is not limited to these examples.

[Examples 1 and 2]
A member having the structure shown in FIG. 2 is formed on the outer periphery in the vicinity of the lower end of the cylindrical carbon reaction tube. The member has a ring slit-like gas supply port for supplying seal gas and / or etching gas to the lower end of the reaction tube. Production of polycrystalline silicon and hydrogen reduction of chlorosilane gas using a reaction apparatus having an apparatus configuration similar to that of the above-described embodiment in which an annular member 32 (hereinafter referred to as a “gas supply port forming member”) is disposed. Went. As materials for the gas supply port forming member, mullite (Example 1) and silicon nitride (Example 2) using a sintering aid mainly composed of yttrium oxide were used.

The reaction tube was heated to 1500 ° C. to 1600 ° C. by a high frequency induction heating coil, and the reaction was performed while supplying the reaction gas from the upper side of the reaction tube.
During operation of the apparatus, the gases that contact the gas supply port forming member were nitrogen, hydrogen, hydrogen chloride, and trichlorosilane. The temperature of the gas contacting the gas supply port forming member was 1200 ° C., and the temperature of the gas supply port forming member was 1200 ° C. or higher.
After operating for 24 hours under the above conditions, the state of the gas supply port forming member and the purity of the recovered silicon and chlorosilane gas were confirmed. The results are shown in Table 1.

[Comparative Examples 1 to 10]
The reaction was performed under the same conditions as in Example 1 except that the material shown in Table 1 was used as the material for the gas supply port forming member. After the operation for 24 hours, the state of the gas supply port forming member and the purity of the recovered silicon and chlorosilane gas were confirmed. The results are shown in Table 1.

FIG. 1 is a cross-sectional view showing a schematic configuration of a silicon manufacturing apparatus according to an embodiment of the present invention. Fig.2 (a) is sectional drawing which showed the reaction tube lower end part periphery of the silicon manufacturing apparatus in another embodiment of this invention. FIG. 2B is a cross-sectional view taken along line AA in FIG. FIG. 3 is a cross-sectional view showing the periphery of the lower end of a reaction tube of a silicon production apparatus according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Seal gas supply port 3 Gas exhaust port 4 Upper space 5 Raw material gas supply pipe 6 Raw material gas supply port 7 Coolant supply port 8 Coolant discharge port 11 Reaction tube 11a Lower end part 12 Seal gas supply port 15 High frequency induction heating Coils 16a, 16b Cooling jackets 17a, 17b Cooling medium supply ports 18a, 18b Cooling medium discharge port 21 Cooling recovery chamber 22 Cooling gas supply port 23 Silicon outlet 24 Recovered silicon 31 First gas supply port 32 Annular member 33 Second Gas supply port 34 Ring-shaped member 36 Insulating member 37 Seal gas flow 38 Seal gas flow 39 Bottom plate 40 Pore

Claims (3)

A reaction apparatus for reacting chlorosilanes with hydrogen, having a reaction part heated to 1000 ° C. or higher by a high frequency induction heating coil,
The member that is in a temperature range of 1000 ° C. or higher and that is disposed at a position affected by the magnetic flux from the high-frequency induction heating coil is formed of silicon nitride using mullite or an oxide as a sintering aid. A reactor characterized by. A reaction tube formed of carbon as a base material and supplied with chlorosilanes and hydrogen from the upper side to the inside of the tube;
The reaction apparatus according to claim 1, further comprising a high-frequency induction heating coil provided around the outside of the reaction tube.   The member is disposed on the outer peripheral side of the reaction tube, and the member is a member that forms a gas supply port having a ring slit shape for supplying a seal gas and / or an etching gas to the lower end of the reaction tube. The reactor according to claim 2, wherein

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