KR20100086322A - Ingot grower having structure for preventing deformation of quartz crucible - Google Patents

Abstract

PURPOSE: A device for growing an ingot is provided to prevent an accident by preventing the friction between a quartz crucible and a heat shield. CONSTITUTION: A quartz crucible(100) receives silicon melt. A crucible support stand(101) supports the quartz crucible. The upper side of the crucible support stand is lower than the upper side of the quartz crucible. A heater(103) is arranged outside the crucible support stand in order to heat the quartz crucible. An insulation cover(102) is combined with the upper side of the quartz crucible to shield the radiation heat which is directly applied to the quartz crucible. A heat shield(104) is arranged between the crystal ingot and the quartz crucible. A chamber receives the crucible support stand and the heater.

Description

Ingot grower having structure for preventing deformation of quartz crucible}

The present invention relates to an ingot growth apparatus, and more particularly, to an ingot growth apparatus having a structure for protecting a quartz crucible so that the quartz crucible is not physically deformed even in a long time high temperature growing process for manufacturing an ingot. It is about.

In the ingot growth method using the Czochralski (Cz) method, the crystal ingot is grown through the liquid-liquid interface by immersing the seed in the silicon melt (Melt) contained in the quartz crucible and slowly pulling it upward while rotating the seed cable. Figure 1 shows the main configuration and operation of a typical ingot growth apparatus for performing the Czochralski (Cz) method.

Referring to Figure 1 (a), the ingot growth apparatus is a crucible support for enclosing and supporting the quartz crucible 10 and the quartz crucible 10 containing silicon melt (SM) in the internal space after the melting process (Melting) (11), a heater 12 disposed outside the crucible support 11 to provide radiant heat to the quartz crucible 10, and a crystal ingot 1 between the grown crystal ingot 1 and the quartz crucible 10. It is installed so as to surround the heat shield 13 to block the heat flow radiated upward from the silicon melt (SM), and a supporter (Supporter) (14) for supporting the lower portion of the crucible support (11).

In the ingot growth apparatus, the heat shield 13 prevents high-temperature radiant heat emitted from the silicon melt SM from being transferred toward the upper portion of the main body chamber (not shown) and the crystal ingot 1, thereby increasing the growth rate of the ingot. Will be In order to effectively block radiant heat, the bottom width of the heat shield 13 is required to be as large as possible. Accordingly, a very narrow gap is maintained between the inner diameter of the quartz crucible 10 and the outer diameter of the heat shield 13. As the interval between the inner diameter of the quartz crucible 10 and the outer diameter of the heat shield 13 is narrower, the growth rate of the crystal can be increased to improve productivity.

Before the melting process, the quartz crucible 10 is supplied into the ingot growth apparatus with polycrystalline silicon contained therein. At this time, in order to facilitate handling such as movement of the quartz crucible 10, it is preferable that a crucible cover (not shown) is mounted on the top of the quartz crucible 10. To this end, the upper end of the quartz crucible 10 is generally provided in a relatively high structure compared to the upper end of the crucible support 11.

As shown in (b) of FIG. 1, during the pulling process, the supporter 14 is driven to rotate the crucible support 11 in a predetermined direction while the position of the solid-liquid interface is independent of the remaining amount of the silicon melt SM. The crucible support 11 is gradually raised to maintain a constant level. At this time, since the quartz crucible 10 and the heat shield 13 cross each other up and down at a fine interval, it is very important to maintain the shape of the quartz crucible 10 to avoid mutual friction.

On the other hand, recently, in order to improve productivity in the Czochralski (Cz) process for growing silicon single crystals, the silicon melt is increased to 400 kg or more when the 300 mm diameter ingot is taken out, or multiple ingots are drawn out with one quartz crucible. A method of performing a multi-pulling or the like is used. In this case, a quartz crucible is etched or deteriorated by a prolonged process, thereby lowering a single crystal yield.

During the growth of silicon single crystals, single crystals may be changed to polycrystals due to particles, temperature deviations, etc. In this case, a melt back process is performed in which the grown single crystals are melted again in a melt form. As the number of melt back processes increases in the single pulling process, the high temperature processing time increases, which increases the damage of the quartz crucible containing the melt. In addition, in the multi-pulling process, a high temperature process may be performed for an average of 160 hours or more, and the quartz crucible may be deformed by drawing out several ingots.

In particular, in the melting process (see (a) of FIG. 2) or the melt back process (see (b) of FIG. 2) for melting the polycrystalline silicon at a high temperature, the quartz crucible 10 may be formed by high temperature radiant heat emitted from the heater 12. As a result of direct heating, the phenomenon in which the upper portion of the quartz crucible 10 is deformed as shown in FIG. 3 (see dotted line) often occurs. In this regard, FIG. 4 shows the actual shape of the quartz crucible 10 deformed after the melt back process (see dotted line).

When the quartz crucible 10 is deformed, such as bending, the quartz crucible 10 and the heat shield 13 are not only rubbed with each other but also the process conditions are changed so that the quartz crucible 10 cannot be processed. Discard all silicon melt (SM) in At this time, it is impossible to solidify the entire silicon melt (SM) to lift out of the growth apparatus because parts surrounding the quartz crucible 10 are damaged due to the volume expansion of the silicon solid. Therefore, a method of growing an ingot of very small length several times to reduce the amount of silicon melt little by little, and then solidifying the remaining melt remaining in the quartz crucible 10 to be taken out of the growth apparatus. These operations are not only time-consuming and economically costly, but also dangerous and may cause safety accidents.

As a technique related to the process of growing a silicon single crystal ingot in consideration of the physical deformation of the quartz crucible, for example, a method of manufacturing a silicon single crystal disclosed in Korean Patent Publication No. 2007-46741 may be mentioned. The above patent discloses a technique for controlling the pulling speed in consideration of the deformation of the crucible.

However, the above-mentioned patent also discloses a fundamental solution to problems such as physical deformation caused by high temperature heater heat, that is, thickness change due to bending or sagging near glass transition temperature, surface peeling, and the like. Is still not present. Physical deformation of the quartz crucible makes it difficult to produce high quality single crystals by engaging the heat and material transfer mechanisms in the Cz method and disturbing the axial symmetry of the single crystal ingots.

The present invention has been made to solve the above problems, an ingot growth apparatus having a protective structure to prevent the upper portion of the quartz crucible from being deformed by the heat of the heater (heater) applied during the high temperature process for crystal growth. The purpose is to provide.

In order to achieve the above object, the present invention is a quartz crucible having an inner space capable of accommodating silicon melt, a crucible support for enclosing and supporting the quartz crucible, and disposed outside the crucible support. An ingot growth apparatus for performing a Czochralski (Cz) method comprising a heater for heating a quartz crucible, and a chamber for accommodating the quartz crucible, the crucible support and the heater, wherein the quartz crucible is formed from the heater. And an insulating cover coupled to the upper portion of the quartz crucible so as to block radiant heat applied directly to the quartz crucible.

The top of the crucible crucible has a relatively high structure compared to the top of the crucible support, the insulating cover may be coupled to surround the outer peripheral surface adjacent to the top of the quartz crucible.

Alternatively, the insulation cover may be coupled to surround the top circumference of the quartz crucible.

The heat insulation cover is preferably made of graphite (Craphite) or CCM (Cabon Composite Material).

According to the present invention, by preventing the radiant heat of the heater from being directly applied to the upper part of the quartz crucible during the high temperature process for crystal growth, physical deformation (bending, flowing down, surface peeling, etc.) of the upper part of the quartz crucible by the high temperature heat is prevented. Can be.

Therefore, when the present invention is applied to the ingot growth process according to the Czochralski (Cz) method, it is possible to improve the yield of single crystals or polycrystals, and there is an advantage of preventing safety accidents by preventing friction between the quartz crucible and the heat shield. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

5 is a cross-sectional view showing the main configuration of the ingot growth apparatus according to an embodiment of the present invention.

Referring to FIG. 5, an ingot growth apparatus according to an exemplary embodiment of the present invention may include a quartz crucible 100, a crucible support 101 surrounding and supporting a quartz crucible 100, and a quartz crucible 100. Between the heat insulating cover 102 coupled to the top, the heater 103 disposed outside the crucible support 101 to heat the quartz crucible 100, and between the growing crystal ingot 1 and the quartz crucible 100. The heat shield 104 is disposed, and the supporter 105 supports the lower portion of the crucible support 101. Although not shown in the figures, the components are housed in a dome chamber of the ingot growth apparatus.

Polycrystalline silicon is loaded in the internal space of the quartz crucible 100 as an ingot raw material, and the polycrystalline silicon is melted by the radiant heat of the heater 103 and converted to the silicon melt SM.

The crucible support 101 is closely coupled to surround the outer circumferential surface of the quartz crucible 100 to support the quartz crucible 100. The crucible support 101 is preferably made of graphite (Graphite) having both heat resistance and conductivity, or CCM (Cabon Composite Material) material having heat resistance and insulation.

The heater 103 is installed to surround the cylindrical crucible at a predetermined distance from the side wall of the crucible support 101 to provide radiant heat inside the crucible by heating the quartz crucible 100.

The upper end of the quartz crucible 100 has a structure that protrudes relatively higher than the upper end of the crucible support 101.

Insulating cover 102 is coupled to the protruding portion of the quartz crucible 100 for the progress of the high temperature process for crystal growth to prevent physical deformation of the upper part of the quartz crucible 100 by the heat of the heater 103. The insulation cover 102 is closely coupled to surround the outer circumferential surface adjacent to the top of the quartz crucible 100 in the form of a ring so that the upper portion of the quartz crucible 100 is directly exposed to the radiant heat applied from the heater 103. prevent.

In order to more effectively prevent direct heating to the quartz crucible 100, the heat insulation cover 102 is preferably tightly coupled to the upper end of the crucible support 101. As the material of the heat insulating cover 102, in consideration of the bonding with the crucible support 101, thermal expansion coefficient, thermal conductivity, and the like, it is preferable that graphite or CCM (Cabon Composite Material) is adopted.

According to another preferred embodiment of the present invention, there is provided an ingot growth apparatus having an insulating cover 102 having a structure that is coupled to surround the top of the quartz crucible 100 as shown in FIG.

The insulation cover 102 is provided in a form surrounding the outer circumferential surface of the quartz crucible 100 in a ring shape and at the same time surrounding the upper circumference of the quartz crucible 100. In this embodiment, the heat insulation cover 102 extends to the inner circumferential surface adjacent to the top of the quartz crucible 100 while surrounding the top of the quartz crucible 100. According to such a structure, the upper end of the quartz crucible 100 may be more effectively prevented from being directly exposed to the radiant heat of the heater 103, and may physically support the upper end of the quartz crucible 100 more physically.

The heat insulation cover 102 is used in a high temperature process for crystal growth according to the Czochralski (Cz) method, and may be removed as necessary before and after the high temperature process. When the insulation cover 102 is removed, a predetermined crucible cover for closing the opening of the quartz crucible 100 in order to provide convenience of handling such as movement of the quartz crucible 100 in the portion where the insulation cover 102 is located. May be combined.

The ingot growth apparatus having the above configuration is applied to the crystal growth process of Czochralski (Cz) method that performs the melting process or the melt back process.

In the crystal growth process, the quartz crucible 100 is heated by radiant heat provided from the heater 103. At this time, since the insulating cover 102 is provided on the upper portion of the quartz crucible 100, the upper end or the adjacent portion of the quartz crucible 100 is not directly exposed to radiant heat. Therefore, physical deformation in which the quartz crucible 100 is bent or flowed down by high temperature heat can be prevented.

When radiant heat is applied to the quartz crucible 100, the polycrystalline silicon raw material loaded on the quartz crucible 100 is melted in the form of a silicon melt SM. After the crystal seed is immersed in the silicon melt (SM), the seed is slowly pulled upward while rotating the seed to grow a crystal through a solid-liquid interface to produce a single crystal or a polycrystalline ingot.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention serve to further understand the technical spirit of the present invention, the present invention includes matters described in such drawings. It should not be construed as limited to.

1 is a cross-sectional view showing the configuration and operation of the ingot growth apparatus according to the prior art.

2 is a cross-sectional view schematically showing the heat distribution of the ingot growth apparatus during the melting process and the melt back process according to the prior art.

FIG. 3 is a cross-sectional view illustrating a deformation occurring in an upper portion of a quartz crucible by the heat distribution of FIG. 2.

Figure 4 is a photograph showing the actual deformation of the top of the quartz crucible generated by the melt back process according to the prior art.

5 is a cross-sectional view showing the main configuration of the ingot growth apparatus according to an embodiment of the present invention.

6 is a cross-sectional view showing the main configuration of the ingot growth apparatus according to another preferred embodiment of the present invention.

<Description of Major Reference Marks in Drawings>

100: quartz crucible 101: crucible support

102: heat insulation cover 103: heater

104: heat shield 105: supporter

Claims (4)

A quartz crucible having an internal space for accommodating a silicon melt, a crucible support for surrounding and supporting the quartz crucible, a heater disposed outside the crucible support to heat the quartz crucible, In the ingot growth apparatus for performing the Czochralski (Cz) method, comprising a chamber for receiving the quartz crucible, the crucible support and the heater, And an insulating cover coupled to an upper portion of the quartz crucible so as to block radiant heat directly applied to the quartz crucible from the heater. The method of claim 1, Compared to the top of the crucible support, the top of the quartz crucible has a relatively high structure, Insulation cover is characterized in that the ingot growth apparatus surrounding the outer peripheral surface adjacent to the top of the quartz crucible. The method of claim 1, Compared to the top of the crucible support, the top of the quartz crucible has a relatively high structure, The insulator cover is characterized in that the ingot growth apparatus surrounding the top of the quartz crucible. The method according to any one of claims 1 to 3, The insulation cover is ingot growth apparatus, characterized in that made of graphite (Craphite) or CCM (Cabon Composite Material).

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