KR20120140158A - Apparatus for fabricating ingot and method for ingot - Google Patents

Abstract

PURPOSE: An apparatus and method for manufacturing an ingot are provided to grow a single crystal with high quality by uniformly and continuously mixing raw materials. CONSTITUTION: An apparatus for manufacturing an ingot includes a crucible(100) and a stirring unit(180). The crucible receives raw materials(130). The stirring unit is arranged in the raw materials in the crucible. The stirring unit is extended from the lower side of the crucible in a vertical direction of the crucible.

Description

Ingot manufacturing apparatus and ingot manufacturing method {APPARATUS FOR FABRICATING INGOT AND METHOD FOR INGOT}

The present disclosure relates to an ingot production device and an ingot production method.

In general, the importance of the material in the electrical, electronics industry and mechanical parts field is very high, which is an important factor in determining the characteristics and performance index of the actual final component.

SiC has excellent thermal stability and excellent oxidation resistance. In addition, SiC has an excellent thermal conductivity of about 4.6W / Cm ℃, has the advantage that can be produced as a large diameter substrate of 2 inches or more in diameter. In particular, SiC single crystal growth technology is most stably secured in reality, and industrial production technology is at the forefront as a substrate.

In the case of SiC, a method of growing silicon carbide single crystals by sublimation recrystallization using seed crystals has been proposed. The silicon carbide powder used as a raw material is accommodated in a crucible, and the silicon carbide single crystal which becomes a seed crystal is arrange | positioned on the upper part. By forming a temperature gradient between the raw material and the seed crystal, the raw material in the crucible is diffused to the seed crystal side and recrystallized to grow a single crystal.

Embodiments can grow high quality single crystals.

Ingot manufacturing apparatus according to the embodiment, the crucible for receiving the raw material; And a stirring unit disposed in the crucible.

Ingot manufacturing method according to the embodiment, the step of charging the raw material into the crucible; Synthesizing the raw material to produce a synthesized raw material; And growing single crystals from the synthesized raw material, wherein the preparing includes first stirring with a stirrer located in the raw material.

The ingot manufacturing apparatus which concerns on an Example contains a stirring part. The stirring unit can be uniformly mixed with the raw material by rotating in the raw material.

Specifically, the stirring unit may be made to be continuous and uniform mixing in the synthesis of the raw material. Therefore, sintering of the synthesized raw material can be prevented, and a high quality raw material can be manufactured.

In addition, the stirring unit may prevent a phenomenon in which the raw material is locally concentrated during single crystal growth, and may efficiently supply the raw material. This can effectively induce single crystal growth.

In addition, since the stirring part contains graphite, the self-heating can be generated by the heat generating induction part. Therefore, the temperature gradient formed in the horizontal region of the raw material can be uniformly formed. As a result, the single crystal can be prevented from having a convex shape due to the temperature gradient, and the single crystal can grow flat. Therefore, the yield of the wafer etc. which are manufactured from the said single crystal can be improved.

In addition, the smaller the convexity of the single crystal, the lower the probability of defect occurrence of the single crystal. Thereby, high quality single crystal can be grown.

Ingot manufacturing apparatus according to another embodiment, the stirring unit and the filter unit, the upper end of the stirring unit may be fixed to the filter unit.

Ingot manufacturing method according to the embodiment may include a first stirring step and a second stirring step. The first stirring step may be made of a stirrer located in the raw material. In the first stirring step, a mixture of silicon and carbon, which are starting materials for synthesizing SiC powder, may be stirred. Since the first stirring step is performed during synthesis into the SiC powder, continuous and uniform mixing of the raw materials may be achieved. Therefore, sintering of the synthesized SiC powder can be prevented, and high quality SiC powder can be synthesized.

In the second stirring step, a phenomenon in which the synthesized SiC powder is locally concentrated can be prevented, and raw materials can be efficiently supplied. This can effectively induce single crystal growth. In addition, by preventing the non-uniform sublimation of the raw material due to the temperature difference of the crucible wall side and the inside of the crucible, it is possible to achieve a uniform sublimation in the horizontal region of the raw material. Therefore, exhaustion of the raw material can be induced, and high quality single crystal can be obtained.

The first stirring step and the second stirring step may be performed continuously. That is, the manufacturing step and the step of growing a single crystal can be made in a continuous manner, the process can be simplified, and a single continuous process can be realized.

1 is a cross-sectional view of the ingot production device according to the first embodiment.
2 is a perspective view of a stirrer included in the apparatus for producing ingots according to an embodiment.
3 is a cross-sectional view of the ingot production device according to the second embodiment.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all formed directly or through another layer. Criteria for the top / bottom or bottom / bottom of each layer will be described with reference to the drawings.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

With reference to FIG. 1 and FIG. 2, the ingot manufacturing apparatus which concerns on a 1st Example is demonstrated in detail. 1 is a cross-sectional view of the ingot production device according to the first embodiment. 2 is a perspective view of a stirrer included in the apparatus for producing ingots according to an embodiment.

1 and 2, the ingot manufacturing apparatus 10 according to the first embodiment includes a crucible 100, a stirring unit 180, a rotation shaft 190, an upper cover 140, and a seed crystal holder 160. ), The heat insulating material 200, the quartz tube 400 and the heat generating induction part 500.

The crucible 100 may accommodate the raw material 130.

The crucible 100 may have a cylindrical shape to accommodate the raw material 130.

The crucible 100 may include a material having a melting point higher than the sublimation temperature of silicon carbide.

For example, the crucible 100 may be made of graphite.

In addition, the crucible 100 may be coated with a material having a melting point higher than the sublimation temperature of silicon carbide. Here, it is preferable to use a material chemically inert to silicon and hydrogen at the temperature at which the silicon carbide single crystal is grown as the material to be applied on the graphite material. For example, metal carbide or metal nitride may be used. In particular, a mixture comprising at least two or more of Ta, Hf, Nb, Zr, W and V and a carbide comprising carbon may be applied. In addition, a mixture comprising at least two or more of Ta, Hf, Nb, Zr, W and V and a nitride comprising nitrogen may be applied.

The raw material 130 may include silicon and carbon. Specifically, the raw material 130 may be a compound containing silicon, carbon, oxygen and hydrogen. The raw material 130 may be silicon carbide powder (SiC powder).

The stirring unit 180 may be located in the crucible 100. The stirring unit 180 may be disposed in the raw material 130.

The stirring unit 180 may have a shape extending from the lower portion of the crucible 100 in the longitudinal direction of the crucible 100. The stirring unit 180 may have a cylindrical shape. However, the embodiment is not limited thereto, and the stirring unit 180 may have various shapes.

The stirring unit 180 may include a support unit 180a and a transport unit 180b.

The support 180a may rotate.

The transport unit 180b may be located on an outer circumferential surface of the support unit 180a. As shown in FIG. 2, the transport unit 180b may have a wing shape forming a spiral surface. The transport unit 180b may transport materials.

As the support unit 180a rotates, the transport unit 180b disposed on the outer circumferential surface of the support unit 180a may uniformly mix and stir the raw material 130.

However, the embodiment is not limited thereto, and the stirring unit 180 may have various shapes.

The stirring unit 180 may include an impeller. The impeller may comprise a screw shape.

The rotary shaft 190 may be disposed below the crucible 100. The rotating shaft 190 and the stirring unit 180 may be connected. The rotating shaft 190 may rotate the stirring unit 180. Therefore, the stirring unit 180 may be rotatably provided.

The stirring unit 180 may be uniformly mixed with the raw material 130 by rotating in the raw material 130.

In detail, the stirring unit 180 may allow continuous and uniform mixing of the raw material 130. Therefore, sintering of the synthesized raw material 130 can be prevented, and a high quality raw material 130 can be manufactured.

In addition, the stirring unit 180 may prevent a phenomenon in which the raw material 130 is concentrated locally during single crystal growth, and may efficiently supply the raw material. This can effectively induce single crystal growth.

At least one stirring unit 180 may be included in the raw material 130. The plurality of stirring units 180 may be spaced apart from each other. Through this, the raw material 130 may be more uniformly mixed.

The stirring unit 180 may include graphite. However, the embodiment is not limited thereto, and the stirring unit 180 may include the same material as the crucible 100. Therefore, the stirring unit 180 may be prevented from affecting the raw material 130. In addition, the stirring unit 180 may use a material that is chemically inert and thermally stable to silicon and hydrogen at a temperature at which the silicon carbide single crystal is grown.

In addition, since the stirring unit 180 includes graphite, the stirring unit 180 may generate heat by the heating induction unit 500. Therefore, the temperature gradient formed in the horizontal region of the raw material 130 can be uniformly formed. As a result, the single crystal can be prevented from having a convex shape due to the temperature gradient, and the single crystal can grow flat. Therefore, the yield of the wafer etc. which are manufactured from the said single crystal can be improved.

In addition, the smaller the convexity of the single crystal, the lower the probability of defect occurrence of the single crystal. Thereby, high quality single crystal can be grown.

Subsequently, an upper cover 140 may be positioned on an upper portion of the crucible 100. The upper cover 140 may seal the crucible 100. The upper cover 140 may include graphite.

The seed crystal holder 160 is positioned at the lower end of the upper cover 140. The seed crystal holder 160 may fix the seed crystal 170. The seed crystal holder 160 may include high density graphite.

The seed crystal 170 is attached to the seed crystal holder 160. The seed crystal 170 may be attached to the seed crystal holder 160, thereby preventing the grown single crystal from growing to the upper cover 140. However, the embodiment is not limited thereto, and the seed crystal 170 may be directly attached to the upper cover 140.

Subsequently, the heat insulator 200 surrounds the crucible 100. The insulation 200 maintains the temperature of the crucible 100 at a crystal growth temperature. Since the heat insulating material 200 has a very high crystal growth temperature of silicon carbide, graphite felt may be used. Specifically, the heat insulator 200 may be a graphite felt made of a cylindrical shape of a predetermined thickness by compressing the graphite fiber. In addition, the heat insulating material 200 may be formed of a plurality of layers to surround the crucible 100.

Subsequently, the quartz tube 400 is located on the outer circumferential surface of the crucible 100. The quartz tube 400 is fitted to the outer circumferential surface of the crucible 100. The quartz tube 400 may block heat transferred from the heat generating induction part 500 to the inside of the single crystal growth apparatus. The quartz tube 400 may be a hollow tube. Cooling water may be circulated in the internal space of the quartz tube 400.

The heat generation induction part 500 is located outside the crucible 100. The heat generating induction part 500 may be, for example, a high frequency induction coil. The crucible 100 can be heated by flowing a high frequency current through a high frequency induction coil. That is, the raw material accommodated in the crucible 100 may be heated to a desired temperature.

A central region that is induction heated in the exothermic induction part 500 is formed at a position lower than a central portion of the crucible 100. Therefore, a temperature gradient having different heating temperature regions is formed on the top and bottom of the crucible 100. That is, a hot zone HZ, which is the center of the heat generating induction part 500, is formed at a relatively low position from the center of the crucible 100, and thus the temperature of the lower portion of the crucible 100 is bounded by the hot zone HZ. Is formed higher than the temperature of the top of the crucible (100). In addition, a temperature is formed high along the outer direction at the inner center of the crucible 100. Due to such a temperature gradient, the sublimation of the silicon carbide raw material 130 occurs, and the sublimed silicon carbide gas moves to the surface of the seed crystal 170 having a relatively low temperature. As a result, the silicon carbide gas is recrystallized to grow into a single crystal.

Hereinafter, an ingot manufacturing apparatus according to a second embodiment will be described with reference to FIG. 3. Detailed descriptions of parts identical or similar to those of the first embodiment will be omitted for clarity and simplicity.

3 is a cross-sectional view of the ingot production device according to the second embodiment.

Referring to FIG. 3, the ingot manufacturing apparatus 20 according to the second embodiment further includes a filter unit 120. The filter unit 120 may be located on the raw material 130. In addition, the filter unit 120 may be formed along the inner wall of the crucible 100.

The filter unit 120 may include a membrane. Specifically, the filter unit 120 may be a fibrous membrane.

The filter unit 120 may be porous. That is, the filter unit 120 may include a plurality of pores 120a.

Since the filter unit 120 is positioned above the raw material 130, the surface of the raw material 130 may be kept flat, and foreign materials that may flow into the raw material 130 may be blocked. In addition, the filter unit 120 may control high-quality single crystal growth by controlling the sublimation rate of the initial growth material 130.

In addition, the filter unit 120 may selectively pass a specific component. Specifically, the filter unit 120 may adsorb carbon impurities and contaminants. That is, carbon impurities generated from the raw material 130 may be prevented from participating in the single crystal growth process. When the carbon impurity moves to the single crystal, defects may occur in the single crystal.

The filter unit 120 may fix the stirring unit 180. That is, an upper end of the stirring unit 180 may be fixed to the filter unit 120. Through this, the stirring unit 180 can be prevented from being moved or damaged by the rotating centrifugal force.

Hereinafter, the ingot manufacturing method according to the embodiment will be described.

An ingot manufacturing method according to an embodiment includes charging, manufacturing and growing a single crystal.

First, the charging step may be charged to the raw material in the crucible. In one example, the raw material may be Si metal granules and graphite powder for synthesizing SiC powder.

In the preparing step, the synthesized raw material may be manufactured by synthesizing the raw material. That is, the raw material can be synthesized into SiC powder by applying temperature and pressure.

The preparing step may include a first stirring step. The first stirring step may be made of a stirrer located in the raw material. In the first stirring step, a mixture of silicon and carbon, which are starting materials for synthesizing SiC powder, may be stirred. Since the first stirring step is performed during synthesis into the SiC powder, continuous and uniform mixing of the raw materials may be achieved. Therefore, sintering of the synthesized SiC powder can be prevented, and high quality SiC powder can be produced.

Conventionally, since the particle size difference of the raw material Si metal granules and graphite powder is large, it is difficult to perform uniform mixing and homogeneous reaction. In addition, the reaction temperature was also uneven due to the temperature difference between the temperature of the crucible wall and the temperature inside the crucible into which the raw material is charged. As a result, the SiC powder synthesized from the raw material was formed in a semi-sintered form at the center of the crucible, and residual Si was also present. In addition, unreacted carbon existed around.

In the growing of the single crystal, it is possible to grow a single crystal from the synthesized raw material. The growing of the single crystal may include a second stirring of the synthesized raw material. Since the second stirring step is performed in the step of growing the single crystal, the phenomenon in which the raw material is locally concentrated can be prevented, and the raw material can be efficiently supplied. This can effectively induce single crystal growth. In addition, by preventing the non-uniform sublimation of the raw material due to the temperature difference of the crucible wall side and the inside of the crucible, it is possible to achieve a uniform sublimation in the horizontal region of the raw material. Therefore, exhaustion of the raw material can be induced, and high quality single crystal can be obtained.

The first stirring step and the second stirring step may be performed continuously. That is, the manufacturing step and the step of growing a single crystal can be made in a continuous manner, the process can be simplified, and a single continuous process can be realized.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. In addition, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (16)

A crucible for accommodating raw materials; And
Ingot manufacturing apparatus comprising a stirring portion disposed in the crucible. The method of claim 1,
The stirring part is disposed in the raw material ingot manufacturing apparatus. The method of claim 1,
The stirring unit ingot manufacturing apparatus extending in the crucible longitudinal direction from the bottom of the crucible. The method of claim 1,
Ingot manufacturing apparatus comprising at least one stirring portion. The method of claim 1,
The stirring part ingot manufacturing apparatus comprising graphite. The method of claim 1,
The stirring unit is provided with a rotatable rotatable apparatus. The method of claim 1,
The stirring portion support; And
Ingot manufacturing apparatus located on the outer circumferential surface of the support portion, comprising a transport unit for transporting material. The method of claim 1,
The stirring unit ingot manufacturing apparatus comprising an impeller (impeller). The method of claim 1,
The impeller is ingot manufacturing apparatus comprising a screw shape. The method of claim 1,
Ingot manufacturing apparatus that the rotation axis is disposed below the crucible. The method of claim 10,
The stirring unit is ingot manufacturing apparatus connected to the rotating shaft. The method of claim 1,
Further comprising a filter on the raw material,
Ingot manufacturing apparatus that the upper end of the stirring unit is fixed to the filter unit. The method of claim 12,
The filter unit ingot manufacturing apparatus comprising a membrane. Charging the raw material into the crucible;
Synthesizing the raw material to produce a synthesized raw material; And
Growing single crystals from the synthesized raw material,
The manufacturing step ingot manufacturing method comprising the first step of stirring with a stirrer located in the raw material. 15. The method of claim 14,
The step of growing the single crystal, ingot manufacturing method comprising the step of stirring the synthesized raw material. 16. The method of claim 15,
The first stirring step and the second stirring step is a continuous ingot production method.

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