KR20120073658A - Device for manufacturing polysilicon - Google Patents

Abstract

PURPOSE: An apparatus for manufacturing polysilicon is provided to pre-heat silicon core rods based on the compulsive heating of a heat exchanging part and to collect fine silicon powder based on the compulsive cooling of the heat exchanging part. CONSTITUTION: An apparatus for manufacturing polysilicon includes a reactive gas supplying part, silicon core rods(141, 143, 145), and heat exchanging parts(161, 163). The reactive gas supplying part supplies reactive gas into a chamber. The silicon core rods are arranged in the chamber. Polysilicon decomposed from the reactive gas is deposited on the silicon core rods. The heat exchanging parts are adjacently arranged to the silicon core rods and are compulsively heated and cooled.

Description

Polysilicon Manufacturing Equipment {DEVICE FOR MANUFACTURING POLYSILICON}

The present invention relates to an apparatus for manufacturing polysilicon used as a main raw material in the semiconductor industry, the photovoltaic industry, and more particularly, to a polysilicon manufacturing apparatus for depositing polysilicon on a surface of a silicon core rod. It is about.

Polysilicon used as a main raw material in the semiconductor industry, photovoltaic industry, etc. is generally obtained through the following manufacturing process.

First, quartz or sand is reduced with carbon to obtain metal grade silicon (MG-Si), and then further refined to obtain polysilicon from metal grade silicon. The obtained polysilicon is used as a raw material for producing a solar cell substrate (SoG-Si) or as a raw material for producing a semiconductor wafer (EG-Si) depending on the purity.

Polysilicon manufacturing industry is directly related to various industries such as semiconductor industry, photovoltaic power generation industry, fine chemical / materials industry, optical communication industry, organosilicon industry, etc.

As the purification method of metal polysilicon, Siemens method using BELL-JAR TYPE REACTOR, Fluidized bed method, Vapor-to-Liquid Deposition (VLD) method and metal silicon are mainly used. Direct purification, and the like.

The most commonly used method is the Siemens law. This method is a method of producing polysilicon 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 with the heat of resistance. 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, for example, about 1000 ° C. through a preheater, the electrical resistance is drastically lowered, so electricity is well supplied. Thus, early in the polysilicon manufacturing process, a means of preheating the silicon core rods is needed.

Silicon pyrolyzed from the reaction gas, chlorosilane or monosilane, is deposited on the silicon core rod, and some silicon powder is not deposited on the silicon core rod but floats inside the reactor to contaminate the deposited polysilicon. It is a pollutant. Therefore, a separate means for removing or collecting the silicon powder is required.

Conventionally, a preheating device for initially preheating the silicon core rod and a device for collecting fine silicon powder floating in the air without being deposited on the silicon core rod after completion of the polysilicon deposition process are separately provided. Accordingly, the conventional polysilicon manufacturing apparatus has a problem in that a large size occupies a lot of installation space and a manufacturing cost and installation labor cost increase.

In addition, the reaction gas injected from the bottom of the reactor is not uniformly supplied to the entire surface of the silicon core rod in the reactor, the shape of the surface becomes a popcorn (Popcorn) or uniform deposition, there was a problem that the deposition rate is slow.

On the other hand, Japanese Patent Application Laid-Open No. 2009-149498 uses a carbon heater as a heating device in the center of the reactor, and supplies the reaction gas through the reaction gas supply port at the base of the reactor chamber. In this method, polysilicon is deposited on the silicon core rod, which may cause carbon contamination by the carbon heater, and the reaction gas introduced into the reactor from the reaction gas supply port at the base of the chamber is not uniformly supplied to the surface of the silicon core rod. Therefore, there is a problem that the surface quality of the polysilicon produced can be greatly reduced.

SUMMARY OF THE INVENTION The present invention has been proposed in the above background, and an object of the present invention is to provide a polysilicon manufacturing apparatus capable of obtaining high-efficiency, high-purity polysilicon used for initial heating of a silicon core rod.

Another object of the present invention is to provide a polysilicon manufacturing apparatus that can reduce the installation space and manufacturing cost by making the device compact.

Another object of the present invention is to provide a polysilicon manufacturing apparatus capable of increasing the deposition efficiency of a reaction gas and providing a high quality surface state.

In order to achieve the above object, the present invention, the chamber; A reaction gas supply unit supplying a reaction gas into the chamber; A silicon core rod provided inside the chamber and in which polysilicon decomposed from the reaction gas is deposited; Provided is a polysilicon manufacturing apparatus including a heat exchanger disposed adjacent to and spaced apart from the silicon core rod and forcedly cooled.

Preferably, the heat exchanger is forcedly heated prior to the forced cooling to preheat the adjacently disposed silicon core rods.

Preferably, the heat exchanger is provided to be in close contact with the inner wall of the chamber.

Preferably, the reaction gas supply unit includes a reaction gas supply port, and the reaction gas supply port is provided on an inner wall of the chamber between the heat exchange unit and the silicon core rod.

According to the above configuration, the polysilicon manufacturing apparatus of the present invention is implemented so that the heat exchange unit has a function of initially preheating the silicon core rod, as well as the function of collecting the fine silicon powder floating in the air without being deposited on the silicon core rod, By making the device compact, it is useful to reduce installation space and manufacturing cost.

In the polysilicon manufacturing apparatus of the present invention, the heat exchange part is in close contact with the inner wall of the chamber, and the reaction gas is supplied toward the silicon core rod from the reaction gas supply port formed in the inner wall of the chamber therebetween. Therefore, the reaction gas flows evenly along the entire surface of the silicon core rod, thereby having a useful effect of rapidly depositing polysilicon having high purity and high quality surface state.

1 is a cross-sectional view schematically showing a polysilicon manufacturing apparatus according to the present invention.
2 is a cross-sectional view taken along line AA of the polysilicon manufacturing apparatus 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 schematically showing a polysilicon manufacturing apparatus according to the present invention, Figure 2 is a cross-sectional view A-A of the polysilicon manufacturing apparatus of FIG.

First, as shown in FIG. 1, the polysilicon manufacturing apparatus according to the present invention includes a chamber, a reaction gas supply part, a silicon core rod, and a heat exchange part. It may also include an electrode, an exhaust gas outlet, a cooling material supply and a heating material supply.

The chamber may include a base 111, a lower shell 113, an upper shell 115, and a dome shell 117. The base 111, the lower shell 113, the upper shell 115, and the dome shell 117 may be configured to allow cooling material to circulate therein. In addition, the polysilicon manufacturing apparatus may include a cooling material supply unit (not shown) for supplying a cooling material to the base 111, the lower shell 113, the upper shell 115, and the dome shell 117. .

In a preferred embodiment, the cooling material supply unit supplies the cooling material having the lowest temperature to the lower shell 113 from the time when the reaction gas is supplied into the chamber. Most of the supplied reaction gas is pyrolyzed and deposited on the silicon core rod, but some silicon powder is not deposited on the silicon core rod, but is also deposited on the inner wall of the chamber. Since the deposition reaction of the silicon powder occurs easily at a lower temperature, the lowest temperature of the lower shell 113 is controlled to induce the silicon powder to be deposited on the lower shell 113. This is because when a large amount of silicon powder is deposited on the dome shell 117 or the upper shell 115, the quality of the polysilicon rod obtained may be adversely affected.

In one embodiment, the polysilicon manufacturing apparatus according to the present invention further includes a viewing window 119 to allow the inside of the chamber to be identified from the outside. The sight glass 119 is for measuring the diameter of the polysilicon rod to be deposited, and may be installed in the upper shell 115 as an example.

The reaction gas supply unit supplies the reaction gas into the chamber. The reaction gas supply unit may include a reaction gas supply port 121, a reaction gas supply pipe 123, a reaction gas supply station 125, and the like. The reaction gas is chlorosilane or monosilane, and the reaction gas is supplied mixed with a carrier gas such as hydrogen. The reaction gas supply port 121 is provided in the inner wall (base 111 in FIG. 1) of the chamber between the heat exchange part and the silicon core rod.

The exhaust gas discharge part may include an exhaust gas discharge port 131, an exhaust gas discharge pipe 133, a pressure controller, and the like.

The pressure controller adjusts the amount of gas discharged through the exhaust gas outlet 131 to control the gas pressure inside the chamber. The pressure regulator may be implemented by including a pressure detector (not shown), a valve 135 and a controller (not shown). The pressure detector detects the gas pressure inside the chamber, and may convert the distortion generated by the pressure into an electrical signal and output the electrical signal. The valve 135 is used to adjust the amount of gas discharged through the exhaust gas outlet 131. The controller controls the operation of the valve 135 according to the electric signal input from the pressure detector. The controller maintains the gas pressure in the chamber at 1 kgf / cm 2 or more and 10 kgf / cm 2 or less. Here, the pressure control should be made in units of ± 0.05kgf / cm 2, and if the pressure is not finely adjusted, variations in the amount of current and gas flowing through the silicon core rod occur.

The exhaust gas outlet 131 may be provided on the opposite side of the reaction gas supply port 121 based on the silicon core rod. Therefore, the reaction gas supplied through the reaction gas supply port 121 is deposited on the silicon core rod while being pyrolyzed while passing around the silicon core rod, and the non-deposited exhaust gas may be naturally discharged to the exhaust gas outlet 131.

The silicon core rod is provided inside the chamber. Polysilicon decomposed from the reaction gas is deposited on the silicon core rod. The silicon core rod receives a current from the first electrode 151 and energizes the current to the second electrode 153, thereby self-heating and depositing silicon powder decomposed from the reaction gas. The silicon core rod includes a first silicon core rod 141, a second silicon core rod 143, and a third silicon core rod 145. The first silicon core rod 141 and the second silicon core rod 143 are spaced apart from each other. The first silicon core rod 141 is connected to the first electrode 151 and stands up in a direction perpendicular to the base 111 of the chamber. The second silicon core rod 143 is connected to the second electrode 153 and stands up in a direction perpendicular to the base 111 of the chamber. The third silicon core rod 145 connects the first silicon core rod 141 and the second silicon core rod 143.

The electrode is for supplying current to the silicon core rod. The electrode includes a first electrode 151 and a second electrode 153. The first electrode 151 and the second electrode 153 are spaced apart by a predetermined distance. The first electrode 151 and the second electrode 153 are installed on the base 111 of the chamber, but are insulated from the base 111 of the chamber. Here, the first electrode 151 and the second electrode 153 may be implemented as an electrode of graphite (graphite) material.

The heat exchange part, that is, the first heat exchange part 161 and the second heat exchange part 163 are disposed adjacent to the silicon core rod, and are spaced apart from each other to form a space therebetween. In addition, the heat exchange part is provided in close contact with the inner wall of the chamber. For example, as shown in Figure 1, the lower end of the heat exchanger may be formed in close contact with the base 111 of the chamber. Thus, the spaced space between the heat exchanger and the silicon core rod constitutes an inner space and can be isolated from the outer space. In this way, polysilicon having a smooth surface state can be produced at a high deposition rate by further increasing the concentration of the reaction gas around the silicon core rod.

The heat exchange part is typically a heat exchange jacket surrounding the silicon core rod.

The heat exchange part includes a first heat exchange part 161 and a second heat exchange part 163. The first heat exchanger 161 is disposed adjacent to the first silicon core rod 141 to be spaced apart from each other. The second heat exchange part 163 is disposed adjacent to and spaced apart from the second silicon core rod 143.

The heat exchange part is forcedly cooled. Forced cooling is performed when at least one of polysilicon deposition is in progress or after deposition is complete. In addition, the heat exchanger may be forcedly heated prior to forced cooling.

When the heat exchanger part is forcedly cooled, the heat exchanger part can capture fine silicon powder floating in the chamber without being deposited on the silicon core rod. The cooling temperature of the heat exchanger is 5 ° C or more and 150 ° C or less, preferably 5 ° C or more and 50 ° C or less. When the heat exchange part is forcedly heated, the heat exchange part serves to preheat the adjacently disposed silicon core rods for a predetermined time before applying current to the silicon core rod or after applying current to the silicon core rod. The heating temperature of the heat exchanger is 200 ° C or more and 400 ° C or less, and preferably serves to preheat the silicon core rod to a temperature of 150 ° C or more and 300 ° C or less. That is, it is possible to initially perform a function of preheating the silicon core rod, and to collect the silicon powder generated during the process and / or after the process to prevent the deterioration of the polysilicon.

The heat exchange part may include cooling parts 161a and 163a and / or heating parts 161b and 163b. 2 shows an embodiment in which the cooling units 161a and 163a and the heating units 161b and 163b are alternately arranged. However, the present invention is not limited thereto, and may have various embodiments. 1 and 2 illustrate embodiments in which the cooling unit and the heating unit are separately formed, but are not necessarily limited thereto. For example, the cooling and heating materials may be circulated through a single circulation passage.

The cooling units 161a and 163a and the heating units 161b and 163b may be cooling material circulation passages and heating material circulation passages, respectively. Also, alternatively, the heating portions 161b and 163b may be ceramic heaters or metal heaters. In the ceramic heater, the heating element may be made of SiC (silicon carbide), MoSi ₂ (molybdenum silicide), graphite, or the like. The metal heater may be made of a Fe-Cr (iron-chromium) system, a Ni-Cr (nickel-chromium) system, a Fe-Cr-Al (iron-chromium-aluminum) system, or the like.

The cooling material supply unit supplies the cooling material to the cooling units 161a and 163a of the heat exchange unit. The cooling material supply unit may include a cooling material supply pipe 171, a cooling material supply station 173, and the like. In one example, the cooling material may be cooling water, cooling oil or liquefied gas.

The heating material supply unit supplies the heating material to the heating units 161b and 163b. The heating material supply unit may include a heating material supply pipe 181, a heating material supply station 183, and the like. In one example, the heating material may be a heated oil or gas.

Generally, separate materials are used as the cooling material and the heating material, but the present invention is not necessarily limited thereto. For example, the use of a single material as a cooling material and a heating material at different temperatures is not excluded.

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.

121: reaction gas supply port, 131 exhaust gas outlet,
141: first silicon core rod, 143: second silicon core rod,
145: third silicon core rod, 151: first electrode,
153: second electrode, 161: first heat exchanger,
163: second heat exchanger

Claims (15)

A chamber;
A reaction gas supply unit supplying a reaction gas into the chamber;
A silicon core rod provided inside the chamber and in which polysilicon decomposed from the reaction gas is deposited;
Polysilicon manufacturing apparatus characterized in that it comprises a heat exchanger is disposed adjacent to the silicon core rod spaced apart, forced cooling. The method of claim 1,
And the heat exchange part is forcibly heated prior to the forced cooling to preheat the adjacently disposed silicon core rods. The method of claim 2,
Forced heating of the heat exchange unit, the polysilicon manufacturing apparatus, characterized in that heating to a temperature of 200 ℃ to 400 ℃ or less. The method of claim 3,
Forced heating of the heat exchange unit, the polysilicon manufacturing apparatus characterized in that the heating to a temperature of 250 ℃ to 300 ℃ or less. The method of claim 1,
Forced cooling of the heat exchange unit, the polysilicon manufacturing apparatus, characterized in that is performed when at least one of the polysilicon deposition is in progress or after the deposition is completed. The method of claim 1,
The heat exchanger, polysilicon production apparatus characterized in that to collect the fine silicon powder by the forced cooling. The method of claim 6,
Forced cooling of the heat exchange unit, the polysilicon manufacturing apparatus, characterized in that the cooling to a temperature of 5 ° C or more and 150 ° C or less. The method of claim 7, wherein
Forced cooling of the heat exchange unit, the polysilicon production apparatus, characterized in that the cooling to a temperature of 5 ° C or more and 50 ° C or less. The method of claim 1,
The heat exchange unit is a polysilicon manufacturing apparatus, characterized in that the heat exchange jacket surrounding the silicon core rod. The method of claim 1,
The polysilicon manufacturing apparatus further includes a cooling material supply unit,
And the cooling material supply unit supplies at least one of cooling water, cooling oil or liquefied gas to the heat exchange unit. The method of claim 1,
The silicon core rod may include a first silicon core rod and a second silicon core rod spaced apart from each other, and a third silicon core rod connecting the first silicon core rod and the second silicon core rod.
And the heat exchange part includes a first heat exchange part disposed adjacent to the first silicon core rod and a second heat exchange portion disposed adjacent to the second silicon core rod. The method of claim 1,
The heat exchanger is polysilicon manufacturing apparatus, characterized in that provided in close contact with the inner wall of the chamber. The method of claim 12,
And the heat exchange part is in close contact with the inner wall of the chamber such that the space between the silicon core rod is separated from the external space by forming an internal space. The method of claim 1,
The reaction gas supply unit has a reaction gas supply port,
The reaction gas supply port, the polysilicon manufacturing apparatus, characterized in that provided on the inner wall of the chamber between the heat exchange unit and the silicon core rod. The method of claim 1,
The polysilicon manufacturing apparatus further includes an exhaust gas discharge unit,
The exhaust gas discharge portion has an exhaust gas discharge port,
The exhaust gas outlet, the polysilicon manufacturing apparatus, characterized in that provided on the opposite side of the reaction gas supply port based on the silicon core rod.

Images