KR20120000199A - Apparatus for growing single crystal ingot - Google Patents

Abstract

PURPOSE: An apparatus for growing a single crystal ingot is provided to prevent heat from a crucible from being delivered to the end part of a water cooling tube by including a heat insulator which is arranged to surround around the end part of the water cooling tube. CONSTITUTION: A chamber(110) has an accommodation space inside. A crucible(120) is arranged in the chamber and accepts a silicon solution. A heating element(130) is arranged around the crucible and heats the crucible. A water cooling tube(140) cools an ingot which is grown up from the silicon solution. A heat insulator(150) blocks the heat from the crucible not to be delivered to the end part of the water cooling tube.

Description

Apparatus for growing single crystal ingot}

The present invention relates to a single crystal ingot growth apparatus, and more particularly, to a single crystal ingot growth apparatus capable of preventing thermal shock around a water cooling tube installed on an upper portion of the single crystal ingot growth apparatus.

A wafer widely used as a material for manufacturing a semiconductor device refers to a single crystalline silicon thin film. Such wafers include a slicing process for thinly cutting single crystal silicon ingots in the form of a wafer, a lapping process for improving flatness while polishing to a desired wafer thickness, and removal of a damage layer inside the wafer. It is produced into a wafer through a step such as etching (etching), polishing to improve surface mirroring and flatness, cleaning to remove contaminants on the wafer surface.

Here, the single crystal silicon ingot is generally grown and manufactured according to the Czochralski method. This method is a method of melting polycrystalline silicon in a crucible in a chamber, immersing the seed crystal as a single crystal in the molten silicon, and growing it into a silicon single crystal ingot of a desired diameter while gradually raising it.

1 is a cross-sectional view showing a single crystal ingot growth apparatus for growing a single crystal ingot by the conventional Czochralski method.

The single crystal ingot growth apparatus 1 includes a chamber 2 formed in a cylinder, a crucible 3 installed inside the growth chamber to accommodate a silicon melt S, and a heating element 4 for heating the crucible 3. , A water cooling tube 5 through which cooling water is circulated to cool the grown single crystal ingot I, a heat insulating material 6 and a silicon melt S which prevents heat to the crucible 3 from being released to the outside of the chamber 2. It includes a heat shield (7) for blocking the heat transmitted to the water cooling pipe (5) side.

In such a single crystal ingot growth apparatus 1, the seed crystal is grown into a single crystal ingot I by being gradually pulled up in contact with the silicon melt S in the crucible 3.

When the single crystal ingot (I) is grown, crystal defects occur depending on the growth conditions. This crystal defect is closely related to the growth rate of the single crystal ingot I and the temperature gradient at the interface between the silicon component of the silicon melt S and the ingot I. Since crystal defects cause leakage current after being manufactured with a semiconductor chip, and lower the semiconductor manufacturing yield, efforts have been made to suppress the occurrence of crystal defects.

It is important that the growth rate of the single crystal ingot (I) is properly maintained. For this purpose, a water cooling tube (5) through which cooling water is circulated is positioned around the single crystal ingot (I) above the growth chamber (2).

The water cooling tube 5 is usually made of stainless steel, and the cooling water circulates therein. Since the crucible 3 is heated to a high temperature of 1420 ° C. or more, which is the melting point of silicon, in order to melt the silicon, heat from the crucible 3 is largely transferred to the water cooling tube 5, so that the water cooling tube 5 has a significant thermal shock. Will receive. In particular, the end point (P) of the water cooling tube (5) is a portion directly receiving the thermal shock. When the single crystal ingot growth apparatus 1 is used for a long time, the end point P of the water cooling tube 5 which receives the most thermal shock is broken and leakage occurs. This causes the yield of silicon single crystal ingot to be reduced by 50% or more. Therefore, in the single crystal ingot growth apparatus 1, a means for protecting the water cooling tube 5 from the thermal shock transmitted from the crucible 3 is required.

Accordingly, the present invention has been made in view of the above circumstances, and an object thereof is to provide a single crystal ingot growth apparatus capable of protecting a water cooling tube for cooling an grown ingot installed from a chamber of a single crystal ingot growth apparatus from thermal shock. have.

According to an aspect of the present invention for achieving the above object, a single crystal ingot growth apparatus, the chamber having a receiving space therein; A crucible installed in the chamber to receive a silicon melt; A heating element disposed around the crucible to heat the crucible; A water cooling tube for cooling the ingot grown from the silicon melt; A thermal barrier member disposed between the water cooling tube and the growing ingot to surround the end of the water cooling tube to block heat from the crucible from being transferred to the end of the water cooling tube; Characterized in that it comprises a.

In addition, the heat shield is characterized in that it comprises a ring-shaped member, and a lamp-shaped member laminated on the ring-shaped member and the top open.

In addition, the water cooling tube is characterized in that it is installed to surround the growing ingot.

In addition, the surface of the heat shield is characterized in that the heat reflection coating layer for reflecting heat from the crucible is formed.

In addition, the heat reflection coating layer is characterized in that it contains pyro carbon (Pyro Carbon).

In addition, a heat insulating material for blocking heat transfer between the heating element and the inner wall of the chamber; A heat shield for preventing heat from the crucible from being transferred to the water cooling pipe; It characterized in that it further comprises.

In addition, the chamber includes a body portion, and the lid portion of the upper body portion, wherein the water cooling tube is coupled to the lid portion.

In addition, the thermal barrier material is characterized in that it is formed of graphite.

According to another aspect of the present invention for achieving the above object, a single crystal ingot growth apparatus, the chamber having a receiving space therein; A crucible installed in the chamber to receive a silicon melt; A heating element disposed around the crucible to heat the crucible; A cooling body for cooling the ingot grown from the silicon melt; A thermal barrier member disposed between the cooling body and the growing ingot to surround the end of the cooling body to block heat from the crucible from being transferred to the end of the cooling body; It includes, and the surface of the heat shield is characterized in that the heat reflection coating layer for reflecting heat from the crucible is formed.

In addition, the cooling body is installed to surround the growth of the ingot, the heat shield is characterized in that it comprises a ring-shaped member, and a freshly stacked member on top of the ring-shaped member is open.

According to the present invention, since the single crystal ingot growth apparatus includes a heat shield installed around the end of the water cooling tube for cooling the grown single crystal ingot, heat from the crucible can be prevented from being transferred to the end of the water cooling tube. have. Therefore, the end of the water cooling tube which is subjected to the most thermal shock is damaged by long use, and the water circulating inside the water cooling tube is prevented from leaking, thereby increasing the yield of the single crystal ingot in the single crystal ingot growth apparatus, thereby improving the yield of the single crystal ingot. The production cost can be reduced.

In addition, the heat insulating material provided to surround the water cooling tube of the present invention includes a ring-shaped member and a lamp-shaped member, so that the heat-blocking material can be installed by simply stacking the ring-shaped member and the lamp-shaped member in the chamber, so that heat from the crucible is cooled by water. It can effectively prevent the delivery to the end of the tube. This shortens the working time for installing or removing the thermal barrier material in the chamber, thereby improving productivity.

1 is a cross-sectional view showing a single crystal ingot growth apparatus for growing a single crystal ingot by the conventional Czochralski method.
2 is a cross-sectional view showing a single crystal ingot growth apparatus according to an embodiment of the present invention.
3 is a perspective view showing a heat shield of the single crystal ingot growth apparatus of the present invention.
4 (a) to 4 (c) are diagrams sequentially illustrating a process of installing a thermal barrier material in a chamber of the single crystal ingot growth apparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are shown in different drawings.

2 is a cross-sectional view showing a single crystal ingot growth apparatus according to an embodiment of the present invention. 3 is a perspective view showing a heat shield of the single crystal ingot growth apparatus of the present invention.

Referring to FIG. 2, the single crystal ingot growth apparatus 100 according to an exemplary embodiment of the present invention includes a chamber 110, a crucible 120, a heating element 130, a water cooling tube 140, and a thermal barrier material 150. do.

The chamber 110 provides an environment for growing polycrystalline silicon into a silicon single crystal ingot I. The chamber 110 has a cylindrical shape and has an accommodation space therein. Preferably, the chamber 110 includes a body portion 111 and a lid portion 112 stacked on the body portion 111. The lid 112 of the chamber 110 is formed with an opening 113 opened at an upper portion thereof to allow the single crystal ingot I to enter vertically.

Crucible 120 is installed in the chamber 110, where the silicon melt (S) is accommodated. The outer circumferential surface of the crucible 120 is supported by the crucible support 121 formed of graphite. A shaft 122 is formed below the crucible support 121 to rotate the supported crucible 120. For this reason, the silicon melt S accommodated in the crucible 120 maintains a uniform density.

The heating element 130 is installed in the chamber 110 to be spaced apart from the outer circumferential surface of the crucible 120 by a predetermined interval to heat the crucible 120. Like the crucible support 121, the heating element 130 is excellent in thermal conductivity and heat resistance, and is low in thermal expansion and is not easily deformed by heat, and is preferably formed of graphite that is resistant to thermal shock. By the crucible support 121 and the heat generating body 130 of the graphite material, the heating property of the crucible 120 becomes more excellent.

As the crucible 120 is heated by the heating element 130, the high-purity polycrystalline silicon agglomerate contained in the crucible 120 is melted into the silicon melt S. That is, the initial state of the silicon melt S accommodated in the crucible 120 is a polycrystalline silicon agglomerate, and the polycrystalline silicon agglomerate is shaped into a silicon melt S by heating the heating element 130.

Seed crystals for growing the single crystal ingot I enter the chamber 110 through the inlet and outlet 111 of the chamber 110. These seed crystals are grown while immersed in the molten silicon in the crucible 120. While the crucible 120 is rotating, seed crystals are grown into a single crystal ingot I while being pulled up in contact with the silicon melt S. The grown single crystal ingot I is discharged to the outside of the chamber 110 through the entrance 111.

When the single crystal ingot (I) is grown, crystal defects occur depending on the growth conditions. Such crystal defects are closely related to the growth rate of the single crystal ingot I and the temperature gradient at the interface between the silicon component of the silicon melt S and the single crystal ingot I.

It is important that the growth rate of the single crystal ingot I is properly maintained. For this purpose, the water cooling tube 140 in which the coolant is circulated is positioned around the single crystal ingot I above the chamber 110.

The water cooling tube 140 is for cooling the single crystal ingot I grown from the silicon melt S and is installed inside the chamber 110 to surround the outer circumferential surface of the single crystal ingot I. Preferably, the water cooling tube 140 is coupled to the lid portion 112 of the chamber 110 or integrally formed with the lid portion 112 and installed in the chamber 110 in the longitudinal direction. The single crystal ingot I is cooled by the cooling water circulated in the water cooling tube 140, so that the growth rate is appropriately controlled. The outside of the water cooling tube 140 is formed of a metal material, preferably stainless steel (stainless steel).

Since the crucible 120 is heated to a high temperature of 1420 ° C. or more, which is the melting point of the silicon, in order to melt the silicon, the heat from the crucible 120 is substantially transferred to the water cooling tube 140, so that the water cooling tube 140 has a significant thermal shock. Will receive. In particular, an end point of the water cooling tube 140 is a portion directly receiving thermal shock, and when the single crystal ingot growth apparatus 100 is used for a long time, an end point of the water cooling tube 140 which receives a lot of thermal shock is broken and leaks are generated. do. Because of this, since the yield of the single crystal ingot (I) is lowered by 50% or more, the present invention includes a thermal barrier material 150 for blocking heat from the crucible 120 to be transmitted to the end of the water cooling tube 140.

The thermal barrier material 150 is installed between the growing single crystal ingot I and the water cooling tube 140. Preferably, the heat shield 150 is installed to surround the end of the water cooling tube 140. This is because the end portion of the water cooling tube 140 receives the most thermal shock as the portion where the heat from the crucible 120 is transmitted the most. However, since the water cooling pipe 140 is a portion for cooling the single crystal ingot I, the heat shield 150 is preferably disposed only around the end of the water cooling pipe 140.

As the material of the thermal barrier material 150 may be used a variety of materials well known in the art. For example, the thermal barrier material 150 may be made of graphite. The heat reflection coating layer 153 is preferably formed on the surface of the thermal barrier material 150 to reflect heat transmitted from the crucible 120. The heat reflection coating layer 153 preferably includes pyro carbon. Since the pyro carbon coating layer has a reflectance two times higher than that of graphite, the pyro carbon coating layer reflects the heat transferred from the crucible 120 to minimize the heat transferred to the end of the water cooling tube 140. In addition, by preventing heat from being transferred from the crucible 120 to the water cooling tube 140 by the thermal barrier material 150, an improvement in the cooling rate by the water cooling tube 140 can also be expected.

Referring to FIG. 3 as an embodiment of the thermal barrier material 150, the thermal barrier material 150 includes a ring member 151 and a shade member 152 stacked on the ring member 151. The upper portion of the shade member 152 is opened to allow the single crystal ingot I to enter and exit. The outer diameter of the lower end of the lampshade member 152 is preferably formed to be the same as the outer diameter of the ring-shaped member 151.

The single crystal ingot growth apparatus 100 of the present invention prevents heat from the crucible 120 and the heat insulating material 160 installed between the heating element 130 and the inner wall of the chamber 110 to be transferred to the water cooling tube 140. It further comprises a heat shield 170 to.

The heat insulator 160 prevents the heat of the heating element 130 from dissipating toward the inner wall of the chamber 110 and leaking to the outside. In addition, the heat insulator 160 blocks the external heat of the heating element 130 from entering the crucible 120.

The heat shield 170 extends from the lower portion of the water cooling tube 140 to the upper surface of the silicon melt S accommodated in the crucible 120 to block heat from the crucible 120 from being transferred to the water cooling tube 140. .

As described above, the single crystal ingot growth apparatus 100 of the present invention includes a thermal barrier material 150 installed to wrap around an end portion of the water cooling tube 140 for cooling the grown single crystal ingot I. Heat from 120 is prevented from being transferred to the end of the water cooling tube 140. Therefore, the end of the water cooling tube 140 that receives the most thermal shock is damaged by long use, thereby preventing the water circulating in the water cooling tube 140 to leak. This improves the yield of the single crystal ingot I in the single crystal ingot growth apparatus 100, thereby making it possible to produce the single crystal ingot I at a low cost. This results in reducing the production cost of the wafer produced from the single crystal ingot (I).

Hereinafter, referring to FIGS. 4A to 4C, the process of installing the thermal barrier material of the present invention in a chamber will be described.

Referring to FIG. 4A, in a state in which the lid 112 of the chamber 110 is removed, the ring member 151 of the thermal barrier material 150 is seated on the support 115.

Next, referring to FIG. 4B, a fresh member 152 is stacked on the ring member 151 to complete the installation of the thermal barrier material 150.

Next, referring to FIG. 4C, the cover 112 of the chamber 110 is covered to complete the installation of the single crystal ingot growth apparatus 100. The water cooling pipe 140 is coupled to the lid part 112, and thus the water cooling pipe 140 is wrapped by the thermal barrier material 150 by covering the lid part 112. Therefore, the heat from the crucible 120 is prevented from being transferred to the end of the water cooling tube 140 by the thermal barrier material 150.

As described above, the thermal barrier material 150 of the present invention includes a ring-shaped member 151 and a lamp-shaped member 152 for enclosing the water cooling tube 140, and thus, the ring-shaped member 151 and the lamp-shaped member 152 in the chamber 110. ) Can be installed by simply stacking them. This shortens the working time for installing or removing the thermal barrier material in the chamber, thereby improving productivity.

In the above, the water cooling pipe 140 has been described as a means for cooling the single crystal ingot I grown from the silicon melt S, but if the single crystal ingot I can be cooled, the water cooling pipe 140 In addition to this, other cooling bodies may be installed. For example, a cooling body in which air or other cooling fluid is circulated may be installed to cool the single crystal ingot I. Even in this case, the thermal barrier material 150 is installed to surround the end of the cooling body to block heat from the crucible 120 to be transmitted to the end of the cooling body, thereby minimizing thermal shock transmitted to the end of the cooling body. The yield of the single crystal ingot I can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

100: single crystal ingot growth device
110: chamber
111: torso
112: lid portion
120: crucible
130: heating element
140: water cooling tube
150: thermal insulation
151: ring-shaped member
152: shoulder member
153: heat reflection coating layer
160: insulation
170: heat shield
I: monocrystalline ingot
S: Silicone Melt

Claims (5)

In the single crystal ingot growth apparatus,
A chamber having a receiving space therein;
A crucible installed in the chamber to receive a silicon melt;
A heating element disposed around the crucible to heat the crucible;
A water cooling tube for cooling the ingot grown from the silicon melt;
A thermal barrier member disposed between the water cooling tube and the growing ingot to surround the end of the water cooling tube to block heat from the crucible from being transferred to the end of the water cooling tube;
Single crystal ingot growth apparatus comprising a. The method of claim 1,
The thermal barrier material comprises a ring-shaped member and a freshly-shaped member stacked on the ring-shaped member and having an open top. The method of claim 2,
Single crystal ingot growth apparatus, characterized in that the heat reflection coating layer for reflecting heat from the crucible is formed on the surface of the thermal barrier material. The method of claim 3,
The heat reflection coating layer is a single crystal ingot growth apparatus comprising pyro carbon. 5. The method according to any one of claims 1 to 4,
The thermal barrier material is a single crystal ingot growth apparatus, characterized in that formed of graphite.

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