KR101033162B1 - Poly silicon deposition device - Google Patents

Abstract

PURPOSE: A poly silicon depositing apparatus is provided to include a gas supply pipe driving unit which horizontally rotates a gas supply pipe of a gas jetting unit, thereby uniformly depositing poly silicon by uniformly jetting the fixed amount of mixed gases onto a silicon core rod. CONSTITUTION: A reactor(110) comprises a gas inputting hole and a gas discharging hole(112). An electrode unit(121) supplies a current to a silicon core rod(122). The silicon core rod inputs a current to a second electrode by receiving the current from a first electrode. A silicon core rod heating unit(123) heats the silicon core rod before inputting the current to the silicon core rod. A gas jetting unit(124) comprises a plurality of nozzles(124a) and a gas supply pipe(124b) supplying a gas to the nozzles.

Description

Polysilicon Deposition Device {POLY SILICON DEPOSITION DEVICE}

The present invention relates to a polysilicon deposition apparatus, and more particularly, to a polysilicon deposition apparatus capable of depositing uniform polysilicon through the injection control of the reaction gas flowing to the silicon core rod.

Polycrystalline silicon (also known as polysilicon) used as a main raw material in the semiconductor and photovoltaic industries is made of metal-grade silicon by reducing quartz or sand with carbon, and then metal-grade silicon is further refined to further improve the solar cell substrate. It is used as a raw material (SoG-Si), and polysilicon of 11N or more is used as a single crystal raw material (EG-Si) for semiconductor wafer manufacturing. Polysilicon manufacturing industry is directly related to industries such as fine chemicals / materials, optical communication, and organosilicon in addition to semiconductor and solar power generation.

As a method of refining metal grade polysilicon, Siemens method using a bell-jar type reactor, Fluidized bed method, VLD (Vapor-to-Liquid Deposition) method and method of directly purifying metal grade silicon Etc.

The most commonly used method is the Siemens method. This method is to produce polycrystalline silicon by thermally decomposing a reaction gas mixed with hydrogen such as chlorosilane or monosilane and depositing it on a silicon core rod. This method makes the silicon core rod electrically and heats the entire silicon core rod according to the resistance heat. Since silicon has a very high electrical resistance at room temperature, it is difficult to conduct electricity. However, when the silicon core rod is heated to about 1000 ° C, the electrical resistance is drastically lowered, so electricity is well supplied.

It is very important to control the flow of the reaction gas in order to pyrolyze the reaction gas mixed with the carrier gas hydrogen so as to efficiently deposit polysilicon on the heated silicon core rod. However, since the length of the silicon core rod installed in the conventional polysilicon deposition apparatus is about 2 m long, it is very difficult to uniformly deposit polysilicon on the silicon core rod.

The present invention has been proposed in the background as described above, an object of the present invention is to increase the deposition efficiency through the injection control of the reaction gas flowing to the heated silicon core rod, it is possible to uniformly deposit polysilicon on the surface of the silicon core rod It is to provide a polysilicon deposition apparatus.

It is an additional object of the present invention to provide a polysilicon deposition apparatus capable of reducing the amount of reaction gas lost to the outside of the reactor without being deposited on the surface of the silicon core rod.

In order to achieve the above object, the polysilicon deposition apparatus according to an aspect of the present invention, the reactor is formed with a gas inlet through which the reaction gas mixed with the carrier gas is injected and the gas outlet for discharging the gas to the outside, and the reactor A silicon core installed inside and spaced apart by a predetermined distance, the electrode core including a first electrode and a second electrode, and a silicon core that receives current from the first electrode of the electrode part and generates current while passing current through the second electrode of the electrode part. A gas injection unit including a rod, a plurality of nozzles for allowing the reaction gas introduced through the gas inlet of the reactor to flow toward the silicon core rod, and a gas supply pipe connected to the gas inlet of the reactor to supply gas to the nozzle; It includes a gas supply pipe driving unit for rotating the gas supply pipe of the gas injection unit to the left / right.

Polysilicon deposition apparatus according to an additional aspect of the present invention, the nozzles of the gas injection portion is characterized in that the spirally arranged on the inner surface of the heating element.

Polysilicon deposition apparatus according to another additional aspect of the present invention, characterized in that the nozzle is formed in the form of a funnel, the diameter becomes smaller as the nozzles closer to the silicon core rod portion.

According to the above configuration, the polysilicon deposition apparatus of the present invention has a useful effect of increasing the deposition efficiency by controlling the injection of the reaction gas flowing to the heated silicon core rod, and uniformly depositing polysilicon on the surface of the silicon core rod. have.

In addition, the polysilicon deposition apparatus of the present invention is implemented by including a gas supply pipe driving unit for rotating the gas supply pipe of the gas injection unit to the left / right, even if the diameter of the silicon core rod is increased as the polysilicon is deposited on the silicon core rod surface There is a useful effect that the amount of mixed gas (carrier gas and reaction gas) is evenly sprayed on the surface of the silicon core rod to uniformly deposit polysilicon.

In addition, the polysilicon deposition apparatus of the present invention is implemented in the form of a funnel, the diameter of the nozzles of the gas injection portion closer to the silicon core rod portion, so that the mixed gas (carrier gas and reaction gas) is concentrated on the surface of the silicon core rod By minimizing the production and homogeneous reaction of the unreacted material has a useful effect to improve the quality of the deposited polysilicon.

1 is an embodiment showing a cross-sectional view of a polysilicon deposition apparatus according to the present invention,
FIG. 2 is a cross-sectional view taken along line AA of the first heating element 123a of the polysilicon deposition apparatus of FIG. 1;
3 is a partially enlarged view of the gas injector 124 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

1 is a cross-sectional view of a polysilicon deposition apparatus according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of AA including a first heating element 123a of the polysilicon deposition apparatus according to FIG. 1.

First, as shown in FIG. 1, the polysilicon deposition apparatus 100 according to the present invention includes a gas inlet 111 into which a reaction gas mixed with a carrier gas is introduced and a gas outlet 112 through which gas is discharged to the outside. The reactor 110 and the polysilicon deposition unit 120 is formed. In the present specification, the reaction gas mixed with the carrier gas is chlorosilane or monosilane.

The polysilicon deposition unit 120 is installed in the inner space of the reactor 110 and serves to deposit polysilicon by pyrolyzing the reaction gas mixed with the carrier gas supplied through the gas inlet 111. In one embodiment, the polysilicon deposition unit 120 includes an electrode unit 121, a silicon core rod 122, a silicon core rod heating unit 123, a gas injection unit 124, and a gas supply pipe driving unit. And 125.

The electrode unit 121 is for supplying a current to the silicon core rod 122, and the first electrode 121a and the second electrode 121b installed at the bottom of the reactor 110 and spaced apart by a predetermined distance are provided. Include. Here, the first electrode 121a and the second electrode 121b may be implemented as electrodes of graphite material. In addition, the first electrode 121a and the second electrode 121b are installed to be insulated from the bottom of the reactor 110.

The silicon core rod 122 receives current from the first electrode 121a of the electrode unit 121 and mixes with the carrier gas while self-heating while supplying current to the second electrode 121b of the electrode unit 121. It serves to deposit the decomposed silicon gas from the reaction gas. The silicon core rod 122 is connected to the first electrode 121a of the electrode unit 121 and is installed in a direction perpendicular to the bottom of the reactor 110 and the electrode unit 121. A second silicon core rod 122b and a first silicon core rod 122a and a second silicon core rod 122b which are connected to the second electrode 121b of the second electrode 121b and installed in a direction perpendicular to the bottom of the reactor 110. It includes a third silicon core rod 122c for connecting.

The silicon core rod heating unit 123 serves to heat the silicon core rod 122 before inputting a current to the silicon core rod 122. The silicon core rod heating part 123 may be spaced apart from the first silicon core rod 122a by a predetermined distance to surround the first silicon core rod 122a and the first heating element 123a having the heating means 1231 installed therein. And a second heating element 123b surrounding the second silicon core rod 122b spaced apart from the second silicon core rod 122b and having a heat generating means 1231 installed therein.

The heat generating means 1231 may be a ceramic heater such as SiC (silicon carbide), MoSi ₂ (molybdenum silicide), graphite or Fe-Cr (iron-chromium) -based, Ni-Cr (nickel-chromium) -based, Fe-Cr-Al ( Iron-chromium-aluminum) -based metal heaters or oil heaters.

Here, referring to FIG. 2, in one embodiment, the heating means 1231 formed in the first heating element 123a includes a plurality of heaters installed in the height direction of the first heating element 123a. In the plurality of heaters, six heaters may be installed around the first heating element 123a at regular intervals, for example, at 60 degree intervals, and four heaters may be installed at 90 degree intervals.

Referring back to FIG. 1, the gas injection unit 124 may include a reaction gas mixed with a carrier gas introduced into the heating element 123a through the gas inlet 111 of the reactor 110. A plurality of nozzles 124a formed on the surfaces of the first and second heating elements 123a and 123b to flow toward the 122a and 122b and the gas inlet 111 of the reactor 110 are connected to the nozzle 124a. It includes a gas supply pipe 124b for supplying gas to the furnace.

The reaction gas mixed with the carrier gas injected through the plurality of gas injection nozzles 124a is thermally decomposed, and the decomposed silicon gas is deposited on the first and second silicon core rods 122a and 122b. Since the reaction gas mixed with the carrier gas is introduced into the first and second heating elements 123a and 123b and preheated by the heating means 1231 to be injected into the first and second silicon core rods 122a and 122b, In the polysilicon deposition apparatus of the present invention, pyrolysis of a reaction gas mixed with a carrier gas may occur quickly.

1 and 2, in one embodiment, the plurality of gas injection nozzles 124a are installed at positions spaced apart by a predetermined interval in the height direction from the inner surface of the first heating element 123a. In one embodiment, the plurality of gas injection nozzles 124a are helically disposed on the inner side surface of the first heating element 123a. That is, the plurality of gas injection nozzles 124a are not arranged on the same line with each other.

In addition, the nozzles 124a provided at regular intervals around the surface of the first heating element 123a are installed between the plurality of heaters 1231 provided at regular intervals around the first heating element 123a. Accordingly, the radiant heat of the plurality of heaters 1231 is transferred to the first silicon core rod 122a through the gas injection nozzle 124a so that the silicon gas decomposed from the reaction gas mixed with the carrier gas is first silicon core rod 122a. Can be prevented from being deposited unevenly.

The gas supply pipe driver 125 rotates the gas supply pipe 124a of the gas injection part 124 to the left / right. The gas supply pipe driver 125 may be implemented by a motor. The gas supply pipe driver 125 rotates the gas supply pipe 124a by a predetermined angle θ ₂ as polysilicon is deposited on the surface of the silicon core rod 122. Accordingly, even when the diameter of the silicon core rod 122 increases as polysilicon is deposited on the surface of the silicon core rod 122, a certain amount of mixed gas (carrier gas and reaction gas) is uniformly formed on the surface of the silicon core rod 122. It can be sprayed to deposit polysilicon uniformly.

The reactor 110 is parallel to the bottom cooling body 113 having the first cooling rod 113a installed therein, and parallel to the first and second silicon core rods 122a and 112b at one end of the bottom cooling body 113. The lower cooling body 114 is installed in the direction and the second cooling rod (114a) is formed therein, and the upper cooling is installed on the upper surface of the lower cooling body (114) and the third cooling rod (115a) is formed therein, respectively The dome cooler 116 is installed above the upper coolant 116 and has a fourth cooling rod 116a formed therein.

Although not shown in FIG. 1, the reactor 110 includes a cooling water supply device for supplying cooling water to each of the first to fourth cooling rods 113a to 116a. In a preferred embodiment, the cooling water supply device supplies the cooling water having the lowest temperature to the second cooling rod 114a of the lower cooling body 114 from the time when the reaction gas mixed with the carrier gas is supplied into the reactor.

Most of the supplied feed gas is pyrolyzed and deposited on the first and second silicon core rods 112a and 112b, but some silicon powder is not deposited on the silicon first and second silicon core rods 112a and 112b and the reactor It may also be deposited inside 110. Since the deposition reaction of the silicon powder occurs easily where the temperature is low, the lowest temperature of the lower cooling body 114 is controlled to induce the deposition of the silicon powder on the lower cooling body 114. This is because a large amount of silicon powder is deposited on the dome cooling body 116 or the upper cooling body 115, which may adversely affect the quality of the silicon rod 210.

In one embodiment, the polysilicon deposition apparatus 100 according to the present invention further includes a viewing window 117 to allow the inside of the reactor 110 to be identified from the outside. The viewing window 117 is for measuring the diameter of the silicon rod (210) in FIG. 2, and may be installed in the upper cooling body 115. In addition, since a large amount of silicon powder is deposited on the see-through window 117, it may be difficult to check the inside thereof, thereby attaching a hot wire to the glass of the see-through window 117 to increase the temperature to suppress the deposition of the silicon powder to the maximum, thereby facilitating the internal check. .

In one embodiment, the polysilicon deposition apparatus 100 according to the present invention by adjusting the amount of gas discharged through the gas outlet 112 of the reactor 110, to adjust the gas pressure inside the reactor 110 It further includes a pressure regulator (131).

In one embodiment, the pressure regulator 160 may include a pressure detector, a valve, and a valve controller. The pressure detector detects the gas pressure inside the reactor 110 and may be implemented as a pressure detector that converts the distortion generated by the pressure into an electrical signal and outputs the electrical signal. The valve is used to regulate the amount of gas that is discharged through the gas outlet 112. The valve controller controls the operation of the valve in accordance with the electrical signal input from the pressure detector. The valve controller maintains the gas pressure in the reactor 110 at 1 kgf / cm 2 or more and 2 kgf / cm 2 or less. Here, the pressure control should be made in units of ± 0.01kgf / cm 2, and if the pressure is not finely adjusted, a variation occurs in the amount of current and gas flowing through the silicon core rod 122.

As shown in FIG. 1, for example, the gas outlet 112 is formed at an upper surface of the reactor 110. Accordingly, the silicon powder from which the reaction gas is formed through pyrolysis is not deposited on the surfaces of the first and second silicon core rods 122a and 112b, and is accumulated on the upper surface of the reactor 110 to form the first and second silicon core rods ( 122a, 112b) can be prevented from falling on the surface.

3 is a partially enlarged view of the gas injector of FIG. 1. As shown, for example, the plurality of gas injection nozzles 124a is implemented in the form of a funnel in which the diameter decreases as the first silicon core rod 122a is closer to the portion, and the extension line of the center line of the nozzle 124a is the first silicon. The core rod 122a is disposed to form an angle θ ₃ of 5 ° or more and 85 ° or less. Accordingly, the mixed gas (carrier gas and reaction gas) injected through the plurality of gas injection nozzles 124a forms laminar flow on the surface of the first and second silicon core rods 122a, thereby increasing silicon deposition efficiency.

Thus far, the present specification has been described with reference to the embodiments shown in the drawings so that those skilled in the art can easily understand and reproduce the present invention, but this is merely exemplary, and the description Those skilled in the art will understand that various modifications and equivalent other embodiments are possible from the embodiments of the present invention. Accordingly, the true scope of the present invention should be determined only by the appended claims.

100: polysilicon deposition apparatus
110: reactor
111: gas inlet 112: gas outlet
113: bottom cooling body 113a: first cooling rod
114: lower cooling body 114a: second cooling rod
115: upper cooling body 115a: third cooling rod
116: dome cooling body 116a: fourth cooling rod
117: viewing window
121: electrode portion
121a: first electrode 121b: second electrode
122: silicon core rod
122a: first silicon core rod 122b: second silicon core rod
122c: third silicon core rod
123: silicon core rod heating part
123a: first heating element 123b: second heating element
1231: heating means
124: gas injection unit
124a: nozzle 124b: gas supply pipe
125: gas supply pipe driving unit
131: pressure regulator

Claims (8)

A reactor in which a gas inlet through which the reaction gas is introduced and a gas outlet through which the gas is discharged are formed;
An electrode part installed inside the reactor and including a first electrode and a second electrode spaced apart by a predetermined distance;
A silicon core rod that receives current from the first electrode and heats itself while supplying current to the second electrode;
A silicon core rod heating part including a heating element spaced apart from the silicon core rod by a predetermined interval and surrounding the silicon core rod and having a plurality of heat generating means installed therein;
A plurality of nozzles installed inside the heating element and allowing the reaction gas introduced through the gas inlet to flow toward the silicon core rod, and a gas supply pipe connected to the gas inlet to supply gas to the nozzle; A gas injection unit;
A gas supply pipe driver connected to the gas supply pipe to rotate the gas supply pipe, and control a rotation range of the gas supply pipe so that the reaction gas is injected into the entire outer circumferential surface of the silicon core rod; And
A pressure detector configured to adjust a gas pressure inside the reactor by adjusting an amount of gas discharged through the gas outlet and installed at the gas outlet, and detecting a gas pressure inside the reactor, an amount of gas discharged through the gas outlet A pressure regulator including a valve controlling a valve and a valve controller controlling an operation of the valve according to an electrical signal input from the pressure detector;
Including,
The plurality of nozzles are protruded from the heating element to face the silicon core rod is formed to be inclined in one direction,
And each of the plurality of nozzles is disposed between the plurality of heat generating means. The method of claim 1,
The nozzles of the gas injection unit,
Polysilicon deposition apparatus, characterized in that implemented in the form of a funnel, the diameter becomes smaller closer to the silicon core rod portion. delete The method of claim 1 wherein the silicon core rod is:
A first silicon core rod connected to the first electrode of the electrode unit and installed in a direction perpendicular to the bottom of the reactor;
A second silicon core rod connected to the second electrode of the electrode unit and installed in a direction perpendicular to the bottom of the reactor; And
A third silicon core rod connecting the first silicon core rod and the second silicon core rod;
Polysilicon deposition apparatus comprising a. delete The method of claim 1,
The plurality of nozzles are polysilicon deposition apparatus, characterized in that arranged in a spiral on the inner surface of the heating element. The method of claim 1,
The heating means is a polysilicon deposition apparatus, characterized in that any one of a ceramic heater, an oil heater, a metal heater. The method of claim 1,
The gas outlet is a polysilicon deposition apparatus, characterized in that formed on the upper surface of the reactor.

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