JP2009013042A - Apparatus for manufacturing high purity silicon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing high purity silicon with which high purity and crystallinity silicon having a relatively large size can be continuously manufactured by the reduction of silicon tetrachloride by zinc in a system. <P>SOLUTION: The apparatus for manufacturing high purity silicon by the reaction of zinc gas and silicon tetrachloride is equipped with: a reaction column section including a gas generation mechanism for forming the zinc gas and feeding the gas to a reaction column, a supply mechanism for feeding silicon tetrachloride to the reaction column, and a mechanism for forming silicon or a silicon precursor by subjecting the zinc gas and silicon tetrachloride to a catalytic reaction and at the same time, growing, as a silicon crystal, the formed silicon or the silicon precursor by colliding the silicon or the silicon precursor with each other; and a solid-gas separation section for dropping the grown silicon crystal to separate it from a reaction gas and sending the separated silicon crystal to a silicon holding part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an apparatus for producing high-purity silicon by metal zinc reduction of silicon tetrachloride, which can continuously obtain high-purity silicon used for solar cells and electronic components with low energy consumption.

The feature of this technology is a manufacturing apparatus for producing high-purity silicon by reducing silicon tetrachloride with zinc metal, which consumes less energy than the so-called Siemens method, that is, the hydrogen reduction method of trichlorosilane. There is a possibility that it may be about / 10. On the other hand, it is considered unsuitable for the production of ultra-high-purity silicon required for electronic devices, and little investigation has been made until the demand for solar cell silicon related to energy problems in recent years has increased. Recently, however, many studies have been conducted for solar cells.

In other words, the production of silicon by the zinc reduction method of silicon tetrachloride has been known since about 1950, and many technical proposals have been made, and some have been commercialized. However, on the other hand, it is a high-temperature process, and it is difficult to maintain the operation conditions, and it is also difficult to treat the generated zinc chloride. Furthermore, since this production is carried out by a high-temperature gas phase reaction and the reaction is very fast, it is difficult to achieve high purity in which silicon, which is a reaction product, is likely to be very fine particles. For this reason, it is said that there is a problem that it is difficult to separate the raw material gas and the by-product zinc chloride gas.

For this purpose, various ideas have been made. For example, Patent Document 1 and Patent Document 2 propose a method of obtaining silicon by blowing silicon tetrachloride onto the surface of liquid zinc. Although this method is characterized in that silicon can be produced at a relatively low temperature, in reality, it is not easy to separate the solid phase silicon from the liquid layer zinc and the gaseous reaction product zinc chloride. There was a problem that operation became very complicated. In addition, since the process is a batch process, there is a problem in that there are many opportunities for impurities to be mixed into the generated silicon.

Several methods have been proposed in which silicon tetrachloride gas is reduced with zinc gas, and the generated silicon is generated on the reactor wall of the reactor. However, Patent Document 3 controls the precipitation by specifying the gas mixing ratio. As a method for facilitating the deposition and removal of silicon from the furnace wall, Patent Document 4 proposes that a release material be applied to the wall in the reaction vessel. However, since it is a batch process, there are many opportunities for mixing impurities into the generated silicon, and it is difficult to remove and separate silicon tetrachloride as a reaction gas.

On the other hand, in order to grow the generated silicon crystal larger, Patent Document 5 shows that the reaction between the silicon tetrachloride gas and the zinc gas is performed under specified conditions in an inert carrier gas atmosphere. Further, in Patent Document 6, a silicon seed crystal plate is placed in a reaction furnace, or such a wall is formed, and silicon is grown there. However, these also cannot escape from the batch process, and even if they are improved, it has been extremely difficult to prevent contamination with impurities.

In contrast, the present inventors have been studying a high-temperature process using a swirl melting method as a method for continuously generating silicon without generating silicon on the furnace wall of the reactor. About these, invention of patent document 7, patent document 8, patent document 9, patent document 10, patent document 11, etc. has been performed. Although these products are not affected by the furnace wall of the reactor and can be operated continuously, the product silicon shows good performance, but it is a high-temperature process at 1200 ° C or higher, usually around 1410 ° C, which is the melting point of silicon. The purity of about 6-nine is the limit because there are few impurities present in the system but they are easily mixed. Furthermore, the reaction apparatus itself has a problem that it is increased in size to form a cyclone. In addition, since the reaction temperature is extremely high, there is a problem in that the durability of the material constituting the reaction furnace is likely to occur, and there are few problems in a short time, but there is a problem that it is difficult to find a stable apparatus material over a long period of time.

In order to solve these problems, the inventors succeeded in extracting silicon as a single crystal fiber by performing the gas phase reaction method in the same manner in Patent Document 12 but by defining the conditions. In addition, it was made more efficient by taking it out as a melt while purifying high purity. (Patent Document 13) However, in order to form such a fibrous single crystal, it is necessary to react zinc and silicon tetrachloride at a high temperature and a high concentration. Toward this, a new problem has been found that the control of conditions becomes severe. Furthermore, due to the high temperature reaction, the problem that the level of impurities tends to be high sometimes has been found.

However, continuous operation is possible by forming a silicon crystal in the reactor in this way and then melting it. On the other hand, in order to form a crystal, conditions such as temperature and atmosphere are severe. There could be a problem with durability. In addition, it was found that the generated crystals tend to vary, and crystals that are insufficiently grown are sometimes mixed into the exhaust gas in the separation process with the gas. On the other hand, as a method for growing a crystal to be generated in a substantially constant state, it is conceivable to place a seed crystal inside as shown in Patent Document 6, but continuous operation becomes difficult and this does not meet this purpose.

The only method for continuously generating silicon on the seed crystal is to use a so-called fluidized bed. (Non-patent Document 1) However, when zinc chloride is used as a reaction gas in the system, there is a problem that it is difficult to separate and recover the reaction gas and it is difficult to form the fluidized bed itself.

Japanese Patent Laid-Open No. 11-060228 Japanese Patent Laid-Open No. 11-092130 JP 2003-095633 A JP 2003-095632 A Japanese Patent Laid-Open No. 2004-196643 JP 2003-095634 A Japanese Patent Laid-Open No. 2004-210594 JP 2003-342016 A JP 2004-010472 A JP 2004-035382 A JP 2004-099421 A JP 2006-290645 A JP 2006-298740 A Silicon 24 (1994) Baifukan

An object of the present invention is to provide an apparatus for continuously producing relatively high purity and high crystalline silicon in the system by zinc reduction of silicon tetrachloride.

In a production apparatus for producing silicon by reaction of zinc gas and silicon tetrachloride, a gas generating mechanism for generating zinc gas and sending it to the reaction tower, a supply mechanism for sending silicon tetrachloride to the reaction tower, and the zinc gas and A reaction tower including a mechanism for causing silicon tetrachloride to react with each other to produce silicon or a silicon precursor and causing the produced silicon or silicon precursor to collide with each other to grow as a silicon crystal, and the grown silicon crystal This is a high-purity silicon production apparatus having a solid-gas separation unit that is separated and dropped from a reaction gas and sent to a silicon holding unit. As a result, the reaction gas containing silicon or silicon precursor produced by the reaction becomes a turbulent flow, and these silicon or silicon precursors repeatedly collide with each other, so that a silicon crystal having a size of 100 microns or more mainly composed of a single crystal with high purity is obtained. Can be obtained. In other words, in the reaction between silicon tetrachloride and zinc gas under these conditions of use, the silicon or silicon precursor produced by the reaction is very active, or the silicon or silicon precursor produced by the reaction itself serves as the seed crystal. Thus, the present invention has been found by newly finding that a large crystal rapidly grows by colliding with each other in a high temperature state.

As a result, almost all of the silicon tetrachloride introduced is black and becomes a silicon crystal having a particle size of 100 microns or more. When the gas flow is swirled, it tends to be fibrous, and when the flow is disturbed, it seems to be a large needle-like crystal. An apparatus for realizing this generates silicon or a silicon precursor by reacting with a gas generation mechanism that heats supplied zinc to generate zinc gas and send it to a reaction tower and a supply mechanism that supplies silicon tetrachloride, A reaction gas having a mechanism for causing the silicon or silicon precursor to collide with each other and growing as a silicon crystal by turbulent or stirring the flow of the reaction gas containing them, and a solid phase for separating the reaction gas and the silicon crystal following the reaction tower. The gas separation unit has a gas separation unit, and the separated gas is exhausted, and includes an exhaust gas pipe to be sent to a processing unit such as electrolysis, and a silicon holding unit that holds the generated silicon and continuously takes it out as a solid or a melt.

The silicon production apparatus of the present invention is particularly characterized by a reaction tower for growing crystals by mixing and colliding the produced silicon or silicon precursor. That is, the zinc gas generated in the zinc evaporation section is sent to a reaction tower where it reacts with silicon tetrachloride to become silicon or a silicon precursor. A baffle plate is provided in the flow path so as to disturb the flow of the reaction gas containing silicon or silicon precursor, or the gas containing them is stirred by forcibly changing the flow. For this purpose, in the case of a pipe-shaped reaction tower, a baffle plate is provided in the pipe to change the direction of gas flow, thereby increasing the collision of silicon or silicon precursor and growing crystals. Also, the gas containing these precursors is returned to the reaction part of silicon tetrachloride and zinc gas by reaction, or substantially two or more silicon tetrachloride supply parts provided along the gas flow, that is, the reaction part. Crystal growth can also be accelerated by causing dense collisions.

The chemical reaction for performing such a reaction is SiCl ₄ + 2Zn → Si + 2ZnCl _2.
Since this is a disproportionation reaction in which a gas of two molecules is produced from a gas of three molecules, it generally involves a large pressure fluctuation. In particular, silicon tetrachloride has an extremely low boiling point of 57 ° C. and has a very high partial pressure at or near 1000 ° C., which is the reaction temperature. Further, since the gas partial pressure of silicon tetrachloride is abnormally large, there are concerns that the number of molecules of both silicon tetrachloride and zinc per unit volume is small in the gaseous state, and the reaction cannot be carried out smoothly. In order to solve such a problem, it is desirable here to supply silicon tetrachloride to the reaction tower with a low-temperature gas or liquid so that pressure fluctuation is minimized. It was confirmed that the reaction with zinc gas proceeded very quickly even if silicon tetrachloride was liquid, and that there was no problem with the reaction.

Although the actual reaction temperature is unknown in the reaction between silicon tetrachloride at such a low temperature and high-temperature zinc gas, a new finding has been found that the impurity level of the produced silicon is lower. The atmospheric temperature of the reaction part needs to be higher than the boiling point of zinc, which is held by zinc as a gas, and actually 1000 ° C. or higher. The temperature of the reaction tower wall in this portion is more preferably 1030 ° C. or higher so that the generated silicon does not adhere and is not affected by the reaction gas zinc chloride. When silicon tetrachloride is supplied as a gas, an inert gas such as argon can be added as the atmosphere gas in order to minimize the pressure fluctuation of the atmosphere. However, the amount is not the large amount of atmospheric gas used in a normal gas phase reaction, but the necessary minimum amount. The inert gas is preferably an argon gas that has no reactivity and is relatively easily available and has no reactivity. However, it goes without saying that it is most desirable to supply silicon tetrachloride as a liquid in order to carry out the reaction at a high density.

The amount of zinc gas to be supplied and silicon tetrachloride are extremely reducing the high temperature silicon tetrachloride. In other words, the oxidizing action against the atmosphere is extremely strong. It is desirable to always keep the zinc as an oxidizing agent in excess. The material of the reaction tower used here is not particularly specified as long as it is resistant to these, but it is desirable to use high-purity quartz glass in combination with a solid-gas separation section described later under such conditions.

As described above, the wall temperature of the reaction tower is preferably 1030 ° C. or higher. On the other hand, when the wall temperature is 1300 ° C. or higher, energy consumption increases, and there may be a problem in durability of the reaction tower itself. For silicon crystals, no higher temperature is required, so 1300 ° C. is the upper limit.
In this way, silicon or silicon precursor is generated by the reaction of zinc gas and silicon tetrachloride, and is made into a turbulent gas flow together with the reaction gas containing them, and collides with each other with a high concentration in the reaction gas. In this case, silicon having a particle size of 100 microns or more is formed. Of course, the reaction tower portion may be arranged horizontally or vertically.

Next, the reaction gas containing silicon crystals generated in the reaction tower is sent to the solid-gas separation unit, where it is separated into solid silicon, gaseous zinc and zinc chloride mixture gas. Although this separation part is not specified in particular, it is desirable to use a vertical cyclone type separation part. As a result, depending on the gas velocity in the cyclone, particles having a particle size of 1 micron or more can be separated as a solid and fall downward. In this way, the reaction gas containing no solid is taken out from the upper part of the solid-gas separation unit. The silicon crystal falls downward and enters the silicon holding part, and is continuously taken out through the silicon holding part. Although the solid may be taken out, the silicon that has fallen by making the silicon holding part a silicon melt can be melted in the liquid tank and continuously taken out while keeping the reaction part and the outside air secretly. The material of the solid-gas separation part is desirably high-purity quartz glass as described above, and the wall temperature is desirably maintained between 1030 ° C. and 1300 ° C. so as to prevent solid adhesion.

According to the literature, zinc chloride is supposed to corrode quartz glass, but it is found that it hardly corrodes at a temperature of 1030 ° C. or higher, and is more stabilized especially when zinc gas coexists.
Here, the solid-gas separation section may be provided for each reaction tower, but a plurality of reaction towers may be connected to one solid-gas separation section.

According to the present invention, silicon tetrachloride can be almost completely made into silicon particles having a particle size of 100 microns or more or fibrous high-purity silicon, and solid-gas separation can be completely achieved. Further, the silicon produced is continuously taken out from the lower part, but especially when taking out with a melt, silicon is poured into the melted silicon and dissolved, so that it can be easily melted at the melting point of silicon. It became possible to manufacture silicon.

An embodiment of the present invention will be described with reference to the drawings. That is, FIGS. 1, 2 and 3 are schematic diagrams in the case of a horizontal reaction column, and FIGS. 4 and 5 are schematic diagrams in the case of a vertical reaction column. That is, FIG. 1 shows that a baffle plate is provided after the reaction between silicon tetrachloride and zinc gas in a horizontal reaction tower so that a reaction gas containing silicon or a silicon precursor is turbulently caused to collide with each other. 2, the silicon or silicon precursor produced at the first supply port is provided in the second reaction column by providing two silicon tetrachloride supply ports into the zinc gas along the gas flow in the horizontal reaction column. It is made to collide with the silicon or silicon precursor generated at the supply port. FIG. 3 also shows a horizontal reaction tower, in which a part of the reaction gas containing silicon or silicon precursor is returned from its outlet to the front of the silicon tetrachloride supply port by bypass, and silicon or silicon produced at the supply port is shown. It collides with a precursor to promote crystal growth. 4 is a schematic diagram in which the horizontal reaction tower shown in FIG. 1 is a vertical type, and FIG. 5 is a schematic diagram in which the reaction tower in FIG. 2 is a vertical type, with the functions shown in FIGS. It is equivalent.
FIG. 6 is a schematic diagram in which four of these reaction towers are installed radially with respect to one solid-gas separation unit / silicon holding unit.

1 and 4, reference numeral 1 denotes a reaction tower, in which zinc gas from a zinc gas generator 2 and silicon tetrachloride from a silicon tetrachloride supply device 3 are contacted and reacted to form silicon or a silicon precursor. The reaction gas containing them is caused to associate and collide with each other in the stirring unit 6 which makes the reaction gas turbulent by a baffle plate or the like to grow into a silicon crystal of 100 microns or more, and is sent to the solid-gas separation unit 4. The solid-gas separation unit 4 drops silicon, which is solid, downward by a system such as a cyclone, and sends it to the silicon holding unit 5 so as to be continuously taken out. In the silicon holding portion, silicon may be solid, but it is more preferable to hold the melted silicon in advance and drop the solid silicon immediately to melt it, and continuously take out the molten silicon. In order to prevent the gas in the reaction tower from coming out when taking out, a silicon holding part having a partition as shown in the figure is used, and the silicon melt is taken out in an overflow manner.
The gas separated from the solid gas is sent from the gas outlet 11 to the processing device 12 for regenerating the reaction gas such as an electrolytic cell.
The wall temperature of the reaction tower and the solid-gas separation section is higher than 1030 ° C., and the temperature is maintained at 1050 ° C. to 1300 ° C. so that silicon crystals do not adhere to the wall surface.

2 and 5 are the same, but the case where two silicon tetrachloride supply ports are arranged in the reaction tower along the flow of the reaction gas is shown, and the silicon produced in the vicinity of the first silicon tetrachloride supply port is shown. Alternatively, significant crystal growth occurs by the silicon precursor colliding with the silicon or silicon precursor produced near the second silicon tetrachloride feed. The rest is the same as the description of FIGS. Also, in FIG. 3, the silicon is grown by returning a part of the reaction gas containing silicon or silicon precursor once generated or the generated silicon crystal, and the main operation and mechanism are the same as in the other figures. is there.
Examples of experimentally assembled test devices are shown below.

"Example 1"
A small test apparatus shown in FIG. 1 was prepared. In FIG. 1, the inner diameter of the reaction tower 2 was 25 mm and the length was 1000 mm. The material is transparent quartz glass. The solid-gas separation part was a cylinder made of transparent quartz glass having a height of 600 mm and an inner diameter of 70 mm, and the upper end was closed and a reaction gas pipe was attached, and the reaction gas after solid-gas separation was taken out and sent to the processing facility 12. Further, the connection with the reaction tower 1 solid-gas separation section 4 was made in the tangential direction of the solid-gas separation section cylinder so that the gas flow of the reaction tower was directly along the wall in the solid-gas separation section. The zinc gas generator 2 was sent in a fixed amount from the molten zinc holding part 7 to the zinc evaporation part 8, and the zinc evaporation part was immediately evaporated by a high-temperature heater to send the zinc gas to the reaction tower. In addition, the silicon tetrachloride supply device 3 is supplied from the liquid silicon tetrachloride storage tank 9 into the reaction tower by the feeding mechanism 10, but in this embodiment, the silicon tetrachloride supply apparatus 3 is sent to the reaction tower by dropping gravitationally. . Here, the flow of the reaction gas is disturbed, and the position of the holes is changed using a baffle plate group in which circular holes are drilled in a full circle quartz glass plate placed at intervals of 10 cm for mutual collision of silicon or silicon precursor. To disturb the flow of the reaction gas. Here, since the main point is that the generated silicon grows as intended and can be separated from the reaction gas, the silicon holding tank 5 is formed by an alumina crucible placed in the system, and continuous extraction is not considered. The reaction conditions here are a reaction tower of 1050 ° C., a zinc evaporation temperature of 1200 ° C., and silicon tetrachloride is supplied to the reaction tower as a melt from room temperature. The amount ratio of zinc gas and silicon tetrachloride is 2 for the theoretical amount of zinc. Doubled. The temperature of the solid-gas separation part (wall temperature was 1050 ° C.) When operation was performed under such conditions, rod-like silicon containing fibrous silicon was deposited in the crucible of the solid-gas separation part. This particle size was almost 0.1 to 1 mm, black and partly metallic luster, and the treatment section 12 sent through the exhaust gas pipe maintained at 960 ° C. had zinc and zinc chloride. Almost no silicon was observed after the reaction, but when the apparatus was disassembled after the reaction, no silicon was deposited on the glass surface of the reaction tower or solid-gas separation section, and glass devitrification was also observed. There was very little silicon in the exhaust pipe.
On the other hand, when this apparatus was used and the reaction tower temperature was lowered to 1020 ° C., the reaction was carried out, and black deposits that seemed to be silicon were found on the reaction tower wall. A slight amount of silicon crystal was observed growing on the wall.

“Comparison 1”
For comparison, production of silicon was tried under the same conditions except that the apparatus of Example 1 was used and the baffle plate was removed. The reaction tower temperature was 1050 ° C. As a result, about 50% of silicon was accumulated in the crucible as compared with Example 1. In addition, although this silicon was partly black and grew relatively large, more than half of the silicon was brown and not sufficiently grown. In addition, the formation of brown silicon was observed in the exhaust gas pipe. These were thought to be due to the insufficient growth of the generated silicon, and because of this, solid-gas separation could not be performed sufficiently, and some silicon was discharged out of the system together with the exhaust gas.

"Example 2"
Using the horizontal reaction tower shown in FIG. 2, the silicon production experiment was conducted. The basic device size was the same as in Example 1. Moreover, the same thing as Example 1 was used for the solid-gas separation part. In the reaction tower, silicon tetrachloride was added from two places instead of a baffle plate. That is, ½ amount of silicon tetrachloride was supplied from the first inlet on the zinc supply side and ½ amount was supplied from the rear side. The amount of zinc supplied was 1.5 times the theoretical amount of silicon tetrachloride. No baffle was used. The supply zinc gas temperature was 1100 ° C., and silicon tetrachloride was supplied as a liquid. Atmospheric gas was not used. The temperature of the solid-gas separation part was 1100 ° C. As a result, although there was more fibrous silicon than in Example 1 in the crucible, almost similar lamination of black silicon particles was observed. The yield was 95% or more based on the theoretical amount of silicon tetrachloride.

"Example 3"
A silicon production test was conducted using the vertical reaction tower shown in FIG. By adopting a vertical type, silicon tetrachloride was supplied from the bottom to the top, and zinc gas was supplied from the side. The baffle plates in the reaction tower were arranged in the same way as in Example 1, but were based on a row of 2/3 circular baffle plates adjacent to each other in opposite directions. Silicon tetrachloride reacts as a mixed gas of argon and silicon tetrachloride gas by bubbling argon gas into a liquid silicon tetrachloride holding tank equipped with a heater to heat argon gas, silicon tetrachloride gas and silicon tetrachloride mist. Feeded to the tower. Zinc gas was supplied in the same manner as in Example 1, but the temperature of the zinc gas was set to 950 ° C., which was the last temperature at which liquid zinc was generated, to prevent zinc liquefaction and to minimize expansion of silicon tetrachloride gas. The pressure fluctuation accompanying the reaction in the system was minimized. The temperature of the reaction tower was maintained at 1000 ° C. below the nozzle of silicon tetrachloride and 1200 ° C. above and on the baffle plate. The temperature of the solid-gas separation part was 1100 ° C. Due to this reaction, a slight black deposit was observed outside the silicon tetrachloride supply section in the reaction tower.只, the glass wall of the baffle plate was transparent. The glass wall portion of the solid-gas separation portion was kept transparent, and no silicon was attached or formed on the wall portion. In the crucible serving as the silicon holding portion, precipitation of silicon mainly including rod-like crystals having a length of about 1 mm was observed. The efficiency of silicon production was approximately 89-90% with respect to silicon tetrachloride input. The amount of silicon tetrachloride charged at this time was 200 g, and the charging time was 15 minutes.

Example 4
Silicon was generated using the reaction tower shown in FIG. The apparatus was the same as in Example 3, except that the supply direction of zinc and silicon tetrachloride was changed, but the tube diameter and length of the reaction tower were the same as in Example 1. In the operation of this apparatus, silicon tetrachloride was supplied as a mixed gas of silicon tetrachloride and argon in the same manner as in Example 3. The temperature of the zinc gas was 1000 ° C. The temperature of the reaction tower was 1050 ° C., and the temperature of the solid-gas separation part was 1150 ° C. As a result, needle-like silicon crystals containing a slight amount of fibrous silicon were produced. The particle size was 100 μ to 1 mm, and some crystals of several millimeters were also observed. The amount of supplied zinc was set to be twice the theoretical amount with respect to silicon tetrachloride. The amount of silicon produced thereby was 95% or more with respect to silicon tetrachloride.

It is a manufacturing device that produces high-purity silicon that is most suitable for solar cells in a fraction of the power required for current silicon production. It is important to solve future energy problems and global warming problems caused by CO2. It is a technology that becomes a trump card. With the current shortage of energy sources, this technology that can fully utilize solar power has the strength to change the form of all industries.

It is a conceptual diagram of the manufacturing apparatus of this invention. It is a conceptual diagram of the manufacturing apparatus of this invention, and is provided with two silicon tetrachloride supply ports. It is a conceptual diagram of the manufacturing apparatus of this invention, and is made to recirculate a part of reaction gas. It is a conceptual diagram of this invention and makes a reaction tower vertical. It is a conceptual diagram of the present invention, and has two silicon tetrachloride supply pipes in a vertically placed reaction tower. It is a plane conceptual diagram of a manufacturing device when a plurality of reaction towers are arranged radially in one solid gas separation part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reaction tower 2 Zinc gas generator 3 Silicon tetrachloride supply apparatus 4 Solid-gas separation part 5 Silicon holding part 6 Baffle plate 7 Zinc holding supply part 8 Zinc evaporation part 9 Silicon tetrachloride holding part 10 Silicon tetrachloride injection mechanism 11 Gas outlet 12 Processing equipment

Claims (13)

In a production apparatus for producing silicon by reaction of zinc gas and silicon tetrachloride, a gas generating mechanism for generating zinc gas and sending it to the reaction tower, a supply mechanism for sending silicon tetrachloride to the reaction tower, and the zinc gas and A reaction tower including a mechanism for causing silicon tetrachloride to react with each other to produce silicon or a silicon precursor and causing the produced silicon or silicon precursor to collide with each other to grow as a silicon crystal, and the grown silicon crystal A high-purity silicon production apparatus having a solid-gas separation unit that is separated and dropped from a reaction gas and sent to a silicon holding unit. 2. The collision of silicon or silicon precursor is carried out by stirring with a baffle plate provided in the reaction tower while changing the flow direction of the reaction gas containing the silicon or silicon precursor. Purity silicon production equipment. The silicon or silicon precursor is caused to collide with each other by supplying silicon tetrachloride from a plurality of nozzles to the reaction tower, and silicon or silicon precursors generated near both nozzles collide with each other. The high-purity silicon production apparatus according to claim 1. 2. The apparatus for producing high-purity silicon according to claim 1, wherein the mutual collision of silicon or silicon precursor is performed by returning a part of the reaction gas containing silicon or silicon precursor into the reaction tower. 5. The apparatus for producing high-purity silicon according to claim 1, wherein the silicon tetrachloride is supplied by gaseous silicon tetrachloride. 5. The high purity silicon production apparatus according to claim 1, wherein the silicon tetrachloride is supplied by liquid silicon tetrachloride. 5. The high purity silicon production apparatus according to claim 1, wherein the silicon tetrachloride is supplied by a supply mechanism that supplies silicon tetrachloride with a mixed gas of silicon tetrachloride and an inert gas. 8. The high-purity silicon production apparatus according to claim 1, wherein the temperature of the reaction tower wall at a portion where silicon or silicon precursor collides and mixes in the reaction tower is 1030 to 1300.degree. 9. The high-purity silicon production apparatus according to claim 1, wherein the temperature in the vicinity of the supply nozzle into the reaction tower of the zinc gas supply mechanism and the silicon tetrachloride supply mechanism is 950 to 1300.degree. 10. The apparatus for producing high-purity silicon according to claim 1, wherein the solid-gas separation unit for separating the generated silicon and the reactive gas is a vertical cyclone, and has a silicon holding tank at a lower part of the cyclone. The apparatus for producing high-purity silicon according to claim 1, wherein the wall temperature of the vertical cyclone is maintained at 1030 ° C. or higher. 12. The high-purity silicon production apparatus according to claim 1, wherein melted silicon is held in the silicon holding part, and the produced silicon crystal is melted by contact with the melted silicon. . Including a solid-gas separation unit composed of a single vertical cyclone, a silicon holding unit at the lower part of the cyclone, a plurality of zinc supply mechanisms arranged radially around the cyclone, and a reaction tower having a silicon tetrachloride supply mechanism High purity silicon manufacturing equipment.

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