KR101028411B1 - Manufacturing method of poly silicon and manufacturing device for the same - Google Patents

Abstract

The present invention is to produce a high-purity metal silicon with high efficiency, comprising the steps of preparing a first silicon in a molten state; Injecting the first silicon into a crucible to produce a second silicon having a flow falling from top to bottom; Allowing water to be injected into the inner space of the crucible; The flow of the second silicon flows through the space in which the water is being sprayed, and the sprayed water reaches both the surface and the core of the flow of the second silicon, whereby the flow of the second silicon is dispersed. To be a third silicon having; And discharging the third silicon from the crucible and solidifying the third silicon so as to become the fourth silicon.

Description

Manufacturing method of poly silicon and manufacturing device for the same

The present invention relates to a method for producing polysilicon and an apparatus for manufacturing the same, and more particularly, to a method for producing polysilicon and a production apparatus for producing a high quality polysilicon with high efficiency.

With the development of the electronics industry, metal silicon is not only highly usable as it is, but also recently, it is widely used in solar cells and the like, which is processed and used in polysilicon.

Since silicon is usually present in the form of silicon oxide (SiOx) in a natural state, a high purity silicon metal is obtained through a reduction reaction. In particular, when the produced metal silicon contains impurities of a semiconductor process such as boron (B), it has a great influence on the properties of the polysilicon produced later.

On the other hand, when silicon carbide (SiC) is produced during the reduction reaction of silicon oxide, not only the production yield of silicon is reduced but also the furnace can be blocked by the silicon carbide. Therefore, it is very important to prevent the formation of silicon carbide in the final molten silicon in the reduction reaction of silicon oxide.

The present invention is to overcome the above problems and / or limitations, and an object of the present invention is to provide a method for producing polysilicon and a manufacturing apparatus thereof capable of producing high purity polysilicon with high efficiency.

Another object of the present invention is to provide a method for producing polysilicon and an apparatus for producing the polysilicon which can prevent boron, iron, aluminum, etc. from being produced in the produced polysilicon.

Still another object of the present invention is to provide a method for manufacturing polysilicon and an apparatus for manufacturing the same, which can prevent the formation of silicon carbide in molten silicon during the production of polysilicon.

In order to achieve the above object, the present invention comprises the steps of preparing a first silicon in a molten state; Injecting the first silicon into a crucible to produce a second silicon having a flow falling from top to bottom; Allowing water to be injected into the inner space of the crucible; The flow of the second silicon flows through the space in which the water is being sprayed, and the sprayed water reaches both the surface and the core of the flow of the second silicon, whereby the flow of the second silicon is dispersed. To be a third silicon having; And discharging the third silicon from the crucible and solidifying the third silicon so as to be the fourth silicon.

According to another feature of the invention, the step of manufacturing the first silicon, the step of filling the furnace with the first component group consisting of silicon oxide, charcoal, petroleum coke and coal and the second component group consisting of wood or corn core ; And heating the filling filled in the furnace to form a molten state.

The present invention also provides a furnace for producing a first silicon in the molten state to achieve the above object; A crucible provided with a discharge hole so that the inside is formed to form a space from the top to the bottom and the first silicon injected from the furnace toward the space is formed from a second silicon having a flow falling from the top to the bottom; And installed in the crucible to inject water toward the space, wherein the flow of the second silicon passes through the space in which the water is being sprayed, and the sprayed water is formed on the surface and the core of the flow of the second silicon. It provides a device for producing polysilicon comprising a; a plurality of injection nozzles to make all the contact, so that the flow of the second silicon is a third silicon having a dispersed flow.

According to the present invention as described above it is possible to obtain a high-purity polysilicon with a minimum content of impurities.

In addition, by suppressing the production of silicon carbide in the molten silicon, it is possible to improve polysilicon production efficiency and to increase the polysilicon purity.

Hereinafter, with reference to the embodiments of the present invention shown in the accompanying drawings will be described in detail the present invention. But. The present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

1 is a flowchart sequentially illustrating a method of manufacturing polysilicon according to an embodiment of the present invention. 2 to 4 are schematic diagrams illustrating an apparatus for manufacturing polysilicon performing the manufacturing method of FIG. 1.

First, the first silicon 21 in a molten state is manufactured in the furnace 11 (S1).

The furnace 11 may be an electric furnace, but is not necessarily limited thereto.

First, the furnace 11 is filled with a first component group consisting of silicon oxide, charcoal, petroleum coke and coal and a second component group consisting of wood or corn core.

Charcoal, petroleum coke and coal in the first component group and the second component group serve as a source of carbon as a reducing agent.

Silicon oxide preferably contains 46 to 64% by weight. Charcoal and coal each contain 6-7 wt% and petroleum coke 20-20 wt%. And the second component group is to be included 4 to 15% by weight.

According to a preferred embodiment of the present invention, 56.8% by weight of silicon oxide, 6.8% by weight of charcoal, 22.7% by weight of petroleum coke, 6.8% by weight of coal, and 6.8% by weight of wood chips as the second component group. . In this case, it was possible to prevent the formation of silicon carbide in the molten first silicon 21. In addition, the purity of the resulting polysilicon was the best.

According to another embodiment of the present invention, corn cores may be used instead of the wood chips. When using corn cores, it is desirable to add approximately twice the amount of wood chips.

The composition ratio as described above may be adjusted to an appropriate ratio depending on the process conditions.

On the other hand, the silicon oxide, coal, petroleum coke, wood chips, corn core and the like is preferably added to the furnace by adjusting the size and ratio.

In the case of silicon oxide, it is preferable to add a size of 8 to 80mm, at this time, it may be included in the powder less than 20mm, but preferably not more than 20% of the total amount of silicon oxide.

Table 1 below shows the state of the polysilicon produced by the input size of the silicon oxide. As can be seen in Table 1, the input size of the silicon oxide preferably satisfies the above conditions.

Silicon oxide
Input size 1-7mm 8-80mm 8-80mm 8-80mm 81-150mm 151-250mm Input condition Less than 3mm
Less than 20% Less than 20mm
Less than 5% Less than 20mm
Less than 10% Less than 20mm
Less than 20% Less than 20mm
Less than 40% Less than 20mm
Less than 50% Experiment result Bad Good Good The best Bad Bad

Coal preferably has a size of 6 to 10 mm. Some of the fine powder of less than 1mm may be included, but it is preferable not to exceed 20% of the total coal content.

Table 2 shows the state of the polysilicon generated by the input size of the coal. As can be seen from Table 2, the input size of coal preferably satisfies the above conditions.

Coal
Input size 1-5mm 6-10mm 6-10mm 11-15mm 11-15mm 11-15mm 16-20mm 21-25mm Input condition Less than 1mm
Less than 20% Less than 1mm
Less than 10% Less than 1mm
Less than 20% Less than 1mm
Less than 30% Less than 1mm
Less than 40% Less than 1mm
Less than 50% Less than 1mm
Less than 20% Less than 1mm
Less than 20% Experiment result Bad Good The best Bad Bad Bad Bad Bad

The petroleum coke is preferably loaded with a particle size of 30 mm or less. At this time, it is preferable not to exceed 20% of the total petroleum coke amount in the case of fine powder having a diameter of less than 3mm.

Table 3 below shows the state of the polysilicon produced by the input size of the coke. As can be seen from Table 3, the coke input size preferably satisfies the above conditions.

cokes
Input size 0-30mm 0-30mm 0-30mm 60-90mm 90-120mm Input condition Less than 3mm
Less than 40% Less than 3mm
Less than 20% Less than 33mm
Less than 20% Less than 63mm
Less than 20% 93mm or less
Less than 20% Experiment result Bad Good Bad Bad Bad

It is preferable to use wood chips having a size of 10 to 150 mm. It is desirable that the amount smaller than 30 mm does not exceed 20% of the total amount of wood chips.

Table 4 shows the state of the polysilicon produced by the input size of the wood chips. As can be seen in Table 4, the input size of the wood chips preferably satisfy the above conditions.

Wood carving
Input size 1-10mm 10-150mm 10-150mm 150-300mm 300-500mm Input condition Less than 2mm
Less than 20% Less than 3mm
Less than 30% Less than 30mm
Less than 20% Less than 170mm
Less than 20% Less than 320mm
Less than 20% Experiment result Bad Good The best Bad Bad

Corn cores are preferably used having a size of 200 to 250mm. Some of the less than 100mm may be included, but it is preferable not to exceed 20% of the total corn core content.

Table 5 shows the state of the polysilicon produced by the input size of the corn core. As can be seen in Table 5, the input size of the corn core preferably satisfies the above conditions.

cokes
Input size 0-100mm 100-200mm 200-250mm 200-250mm 200-250mm Input condition Less than 100mm
Less than 40% Less than 100mm
Less than 20% Less than 100mm
Less than 20% Less than 50mm
Less than 20% Less than 100mm
Less than 40% Experiment result Bad Good The best Bad Bad

By adjusting the content as described above it was possible to suppress the production of silicon carbide in the molten first silicon 21 to the maximum and the purity of the produced polysilicon could be improved.

These components are loaded into the furnace 11 and then melted at 2000 ° C. or higher to obtain the first silicon 21 in a molten state. At this time, a small amount of oxygen can be blown into the furnace 11.

This first silicon 21 is poured into the first crucible 12 as shown in FIG. 2, and then the first crucible 12 of the first crucible 12 can be seen in FIG. 3. Inject).

The first crucible 12 may be a movable crucible for injecting the molten first silicon 21 into the second crucible 13 by a predetermined amount, although not shown in the drawing, the first crucible 12 may be used. A separate heater facility may be further installed to maintain the temperature of the first silicon 21. Of course, the first silicon 21 may be directly injected from the furnace 11 into the second crucible 13 without using the first crucible 12 separately.

Next, the first silicon 21 is injected into the second crucible 13 from the first crucible 12. At this time, the first silicon 21 discharged from the first crucible 12 becomes a second silicon 22 having a flow falling from the top to the bottom (S2).

The flow of the second silicon 22 flows into the internal space 14 of the second crucible 13 as it is, and water is injected into the space 14 by a plurality of injection nozzles 15. .

That is, as shown in Figure 4, the second crucible 13 is equipped with a plurality of injection nozzles 15 from the top to the bottom along the inner wall. The injection nozzle 15 injects high pressure water into the inner space 14 of the second crucible 13 before the flow of the second silicon 22 flows into the second crucible 13 (S3).

The flow of the second silicon 22 flows into the space 14 of the second crucible 13 into which the high pressure water is injected. At this time, the flow rate of the second silicon 22 flowing into the space 14 of the second crucible 13 is adjusted so that the water sprayed from the injection nozzle 15 flows on the surface of the second silicon 22 flow and It is desirable to reach all over the core. Accordingly, the flow of the second silicon 22 is to be the third silicon 23 having the dispersed flow (S4). In other words, the flow of the second silicon 22 becomes the third silicon 23 having the spray-type flow by the pressure of the water injected from the injection nozzle 15.

As the flow of the second silicon 22 passes through the space where the high pressure water is injected, boron B in the second silicon 22 is removed. Therefore, the amount of boron is reduced as much as possible in the generated third silicon 23 to further increase the purity of the metal silicon formed later.

Meanwhile, at the same time as the high pressure water is sprayed, some spray nozzles 15 may spray oxygen and / or argon gas, and in addition, the air may be mixed and sprayed. In this case, impurities such as iron and aluminum can be removed.

The second crucible 12 is provided with a discharge hole 16, so that the formed third silicon 23 can be discharged as it is (S5).

The discharged third silicon 23 solidifies gradually while flowing along the moving table 17 to become the fourth silicon 24 (S6). Cooling water may be sprayed on the movable table 17 to promote solidification of the fourth silicon 24.

Although not shown in the figure, the fourth silicon 24 is crushed, and then the crushed powder is melted and solidified to produce polysilicon.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims, and various forms of substitution, modification, and within the scope not departing from the technical spirit of the present invention described in the claims. It will be apparent to those skilled in the art that changes are possible.

1 is a flowchart sequentially illustrating a method of manufacturing metal silicon according to an embodiment of the present invention.

2 is a schematic view showing a furnace and a first crucible which are part of the apparatus for producing metal silicon according to one embodiment of the present invention.

3 is a schematic view showing a first crucible, a second crucible, and a moving table that are part of the apparatus for manufacturing metal silicon according to one embodiment of the present invention.

4 is a schematic view for explaining the second crucible of FIG. 3 in more detail.

Claims (3)

Preparing a first silicon in a molten state; Injecting the first silicon into a crucible to produce a second silicon having a flow falling from top to bottom; Allowing water to be injected into the inner space of the crucible; The flow of the second silicon flows through the space in which the water is being sprayed, and the sprayed water reaches both the surface and the core of the flow of the second silicon, whereby the flow of the second silicon is dispersed. To be a third silicon having; And And discharging the third silicon from the crucible and solidifying the third silicon to become fourth silicon. The method of claim 1, The step of manufacturing the first silicon, Filling the furnace with a first component group consisting of silicon oxide, charcoal, petroleum coke and coal and a second group consisting of wood or corn core; And And heating the filling filled in the furnace to form a molten state. A furnace for producing a first silicon in a molten state; A crucible provided with a discharge hole so that the inside is formed to form a space from the top to the bottom and the first silicon injected from the furnace toward the space is formed from a second silicon having a flow falling from the top to the bottom; And It is installed in the crucible to spray water toward the space, the flow of the second silicon to pass through the space in which the water is injected, the sprayed water to both the surface and the core of the flow of the second silicon And a plurality of injection nozzles which make the flow of the second silicon to be the third silicon having the dispersed flow.

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