KR20130115807A - Seed holding apparatus and apparatus for fabricating ingot comprising the same - Google Patents

Abstract

PURPOSE: A seed holding apparatus and an apparatus for fabricating an ingot comprising the same are provided to stably hold a seed and a seed holder by forming a support unit for holding the seed. CONSTITUTION: A seed support unit (20) passes through a seed holder (10). The seed support unit includes a support part (21) and a protrusion part (22). The seed support unit supports the seed. The seed holder includes tantalum, molybdenum, a mixture thereof or a compound thereof. The thickness of the seed holder is 0.1 to 20 mm.

Description

Seed holding device and ingot manufacturing apparatus including the same {SEED HOLDING APPARATUS AND APPARATUS FOR FABRICATING INGOT COMPRISING THE SAME}

The present disclosure relates to a seed crystal holding device and an ingot manufacturing device including the same.

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.

Silicon carbide (SiC) is characterized by excellent thermal stability and excellent oxidation resistance. In addition, silicon carbide has an excellent thermal conductivity of about 4.6W / Cm ℃, has the advantage that can be produced as a large diameter substrate of more than 2 inches in diameter. In particular, silicon carbide 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 silicon carbide, 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.

In order to proceed with this process, the seed crystals in which the single crystals are grown are attached to a separate member such as a crucible lid, for example, and the seed crystals may have a great influence on the quality of the single crystals grown on the surface. Therefore, the seeding process is very important.

Conventionally, an adhesive was used to attach the seed crystal to the seed crystal holder. However, when using such an adhesive, defects may occur due to the penetration of the material contained in the adhesive during the single crystal growth process.

In addition, due to the difference in thermal expansion coefficient between the seed crystal and the seed crystal holder, a phenomenon in which the seed crystal detaches as the single crystal grows may occur.

Therefore, prior to the single crystal growth process, seed crystals and seed crystal holders to which seed crystals are attached are required to be stably and firmly attached. In addition, it is important to attach to the seed crystal holder so that the seed crystal can grow stably.

Embodiments provide a seed crystal fixing apparatus capable of growing high quality single crystals and an ingot manufacturing apparatus including the same.

Seed crystal fixing device according to the embodiment, a seed crystal holder; A seed crystal support penetrates the seed crystal holder and supports the seed crystal.

Ingot manufacturing apparatus according to the embodiment, the crucible for receiving the raw material; And a seed crystal holder positioned above the crucible, wherein the seed crystal holder comprises: a seed crystal holder; A seed crystal support penetrates the seed crystal holder and supports the seed crystal.

Seed crystal fixing device according to the embodiment is a seed crystal holder; A seed crystal support penetrates the seed crystal holder and supports the seed crystal.

Accordingly, in the embodiment, instead of gluing the seed crystal and the seed crystal holder with an adhesive or sugar, the seed crystal holder is tightly fixed to the seed crystal holder using the seed crystal holder.

Therefore, it is possible to prevent the material contained in the adhesive from penetrating into the single crystal during the single crystal growth process to cause defects.

In addition, since the seed crystal holder includes a material having a high melting point and a small porosity such as tantalum and molybdenum, it is possible to prevent defects of the single crystal due to the pores of the seed crystal holder during the single crystal growth process.

That is, in the case of the graphite seed crystal holder used in the prior art, defects due to the formation of fine pores during growth of the single crystal may occur due to pores included in the graphite, but in the case of the tantalum or molybdenum, there are almost no pores. Porosity and the like can prevent defects that may occur during single crystal growth.

Therefore, in the seed crystal fixing device according to the embodiment, the seed crystal holder and the seed crystal holder to which the seed crystal is attached can be stably firmly fixed and adhered to the seed crystal growth process, and grow high quality single crystal.

1 is a view showing a cross section of the seed crystal fixing device according to the embodiment.
2 is a view illustrating a cross section in which seed crystals are fixed to the seed crystal fixing apparatus according to the embodiment.
3 is a view illustrating an upper surface of the seed crystal fixing device of FIG. 2.
4 is a view illustrating the bottom surface of the seed crystal fixing device of FIG. 2.
5 is a view showing a cross-sectional view of the ingot production device according to the 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. The criteria for top / bottom or bottom / bottom of each layer are 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.

A seed crystal fixing device according to an embodiment will be described in detail with reference to FIGS. 1 to 4.

1 is a view showing a cross-section of the seed crystal fixing device according to the embodiment, Figure 2 is a view showing a cross-section of the seed crystal is fixed to the seed crystal fixing device according to the embodiment, Figure 3 is a seed crystal of FIG. It is a figure which shows the upper surface of the fixing device, and FIG. 4 is a figure which shows the lower surface of the seed crystal fixing device of FIG.

1 to 4, the seed crystal fixing device according to the embodiment includes a seed crystal holder 10; A seed crystal support 20 penetrates the seed crystal holder 10 and supports the seed crystal.

The seed crystal holder 10 is a device for fixing seed crystals for single crystal growth. The seed crystal holder 10 may be accommodated in the single crystal growth apparatus while the seed crystal is fixed.

The seed crystal holder 10 may include a material having a melting point of 2200 ° C. or more and a small porosity. For example, the seed crystal holder 10 may include tantalum (Ta), molybdenum (Mo), a mixture thereof, or a compound thereof. The mixture or compound may include tantalum carbide (TaC), tantalum nitride (TaN), molybdenum oxide, molybdenum nitride, and the like containing tantalum or molybdenum. However, the embodiment is not limited thereto, and the seed crystal holder 10 may include various metal materials having a melting point of 2200 ° C. or more and a small porosity.

Conventionally, high density graphite was used as said seed crystal holder. However, since graphite has fine pores, the pores may sublimate and escape the silicon carbide atoms on the back side of the seed crystal, and the bonds of the fine pores (micropipes) and voids are formed by the escaped portions. Cause could be caused.

However, the seed crystal holder 10 according to the embodiment has almost no pores, and includes tantalum, molybdenum, a mixture thereof, or a compound thereof having a melting point of 2200 ° C. or higher, thereby preventing defects from being generated in the single crystal due to the pores. can do.

In addition, the seed crystal holder 10 may have a thickness of 0.1mm to 20mm. When the thickness of the seed crystal holder 10 is less than 0.1 mm, the seed crystal holder may be bent, which may affect the seed crystal fixed to the seed crystal holder, and the thickness of the seed crystal holder 10 may be 20 mm. If it exceeds, it is difficult to accurately measure the temperature of the crystal part during single crystal growth, so it may be difficult to control the polytype change of the single crystal.

The seed crystal support 20 passes through the seed crystal holder 10 and supports the seed crystal.

The seed crystal fixing device according to the embodiment may include a plurality of seed crystal supports 20. Preferably, at least three seed crystal supports may be included. That is, three or more seed crystal supports may pass through the seed crystal holder to support the seed crystal.

The seed crystal support 20 may include the same material as the seed crystal holder 10. For example, the seed crystal support 20 may include tantalum, molybdenum, a mixture thereof, or a compound thereof. The mixture or compound may include tantalum carbide (TaC), tantalum nitride (TaN), molybdenum oxide, molybdenum nitride, and the like containing tantalum or molybdenum. However, the embodiment is not limited thereto, and the seed crystal support 20 may include various metal materials. In addition, the seed crystal support 20 may include a high density graphite, unlike the seed crystal holder 10.

 The seed crystal support may include a support part 21 penetrating the seed crystal holder and a locking part 22 fixing the seed crystal. The support part 21 and the locking part 22 are integrally formed.

The seed crystal support penetrates the seed crystal holder 10. That is, the support part 21 of the seed crystal holder 10 penetrates the seed crystal holder 10. Preferably, the support 21 may penetrate the edge of the seed crystal holder 10. In addition, the support part 21 may move upward and downward through the seed crystal holder 10. That is, the seed crystal holder 10 may be moved up and down in accordance with the thickness of the seed crystal to fix the seed crystal to the seed crystal holder 10 and to be in close contact.

The locking portion 22 may extend in a direction perpendicular to the direction in which the support portion 21 extends. Preferably, the locking portion 22 may extend inward from the edge of the seed crystal holder 10. The locking portion may fix the seed crystal. That is, the seed crystals are supported by the locking portion, and the seed crystals may be brought into close contact with the seed crystal holder 10 by adjusting the support portion in the vertical direction.

The seed crystal support 20 may have a thickness enough to support and fix the seed crystal. That is, the seed crystal support 20 may have a very thin thickness. When the thickness of the seed crystal support is thick, since the loss of the single crystal may occur and the yield may be reduced, the thickness of the seed crystal support 20, that is, the support 21 and the catching part 22 may be reduced. Can be very thin. In addition, the length of the locking portion 22 may also be very short within the range in which the seed crystals are supported.

Conventionally, adhesive or sugar was used when the seed crystal was attached to the seed crystal holder. However, when using such an adhesive or sugar, a material contained in the adhesive may penetrate into the single crystal during single crystal growth, and defects may occur. In addition, due to the difference in thermal expansion coefficient between the seed crystal and the seed crystal holder, the seed crystal may be detached and broken while the single crystal grows.

Accordingly, in the embodiment, instead of adhering the seed crystals and the seed crystal holders with the adhesive or the sugar, the seed crystals are adhered to and fixed to the seed crystal holders using the seed crystal supports. Therefore, it is possible to prevent the material contained in the adhesive from penetrating into the single crystal during the single crystal growth process to cause defects.

In addition, since the seed crystal holder includes a material having a high melting point and a small porosity such as tantalum and molybdenum, it is possible to prevent defects of the single crystal due to the pores of the seed crystal holder during the single crystal growth process. That is, in the case of the graphite seed crystal holder used in the prior art, defects due to the formation of fine pores during growth of the single crystal may occur due to pores included in the graphite, but in the case of the tantalum or molybdenum, there are almost no pores. Porosity and the like can prevent defects that may occur during single crystal growth.

Therefore, in the seed crystal fixing device according to the embodiment, the seed crystal holder and the seed crystal holder to which the seed crystal is attached can be stably firmly fixed and adhered to the seed crystal growth process, and grow high quality single crystal.

Hereinafter, an ingot manufacturing apparatus according to an embodiment will be described in detail with reference to FIG. 5. For the purpose of clarity and simplicity, detailed description of parts identical or similar to those of the seed crystal fixing device will be omitted.

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

Referring to Figure 5 ingot manufacturing apparatus according to an embodiment of the crucible 100, the top cover 140, seed crystal holder 10, seed crystal support 20, focusing tube 180, heat insulating material 200, quartz The pipe 400 and the heat generating induction part 500 is included.

The crucible 100 may accommodate the raw material 130. The raw material 130 may include silicon and carbon. More specifically, the raw material 130 may include a silicon carbide compound. The inner crucible 100 may contain silicon carbide powder (SiC powder) or polycarbosilane (polycarbosilane).

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 upper cover 140 may be located on the top of the crucible 100. The upper cover 140 may seal the crucible 100. The upper cover 140 may include porous graphite. Alternatively, the upper cover 140 may be formed by drilling a plurality of holes in the thin graphite plate. This is for discharging the unreacted impurity gas and the carrier gas to the outside, and may serve to adjust the pressure inside the crucible 100.

The seed crystal fixing device is located at the lower end of the upper cover 140.

The seed crystal fixing device includes a seed crystal holder 10 and a seed crystal holder 20.

The seed crystal 170 is fixed to the seed crystal holding device.

The seed crystal fixing device according to the embodiment fixes and closes the seed crystal to the seed crystal holder by using the seed crystal support instead of bonding the seed crystal and the seed crystal holder with the adhesive or sugar. In addition, the seed crystal holder includes a material having a high melting point and low porosity such as tantalum and molybdenum. Therefore, it is possible to prevent the material contained in the adhesive from penetrating into the single crystal during the single crystal growth process and to prevent defects from occurring, and to prevent the defect of the single crystal due to the pores of the seed crystal holder during the single crystal growth process. That is, in the case of the graphite seed crystal holder used in the prior art, defects due to the formation of fine pores during growth of the single crystal may occur due to pores included in the graphite, but in the case of the tantalum or molybdenum, there are almost no pores. Porosity and the like can prevent defects that may occur during single crystal growth.

The focusing tube 180 is located inside the crucible 100. The focusing tube 180 may be located at a portion where the single crystal grows. The focusing tube 180 may narrow the movement path of the sublimated silicon carbide gas to focus diffusion of the sublimed silicon carbide into the seed crystal 170. This can increase the growth rate of single crystals.

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. Therefore, the quartz tube 400 can more accurately control the growth rate, growth size, and the like of the single crystal.

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 and the crucible 100 may be heated by flowing a high frequency current through the 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. The temperature gradient causes sublimation of the silicon carbide raw material, 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.

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. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in 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 (10)

Seed crystal holder;
A seed crystal holding device penetrating the seed crystal holder, and comprising a seed crystal support for supporting the seed crystal. The method of claim 1,
And the seed crystal holder comprises tantalum (Ta), molybdenum (Mo), mixtures thereof or compounds thereof. The method of claim 1,
And a seed crystal holder having a thickness of 0.1 mm to 20 mm. The method of claim 1,
The seed crystal support is a plurality of seed crystal fixing device. The method of claim 1,
And said seed crystal support comprises graphite, tantalum, molybdenum, mixtures thereof or compounds thereof. The method of claim 1,
And the seed crystal holder penetrates the edge of the seed crystal holder. The method of claim 1,
The seed crystal holder is a seed crystal fixing device including a support for penetrating the seed crystal holder and the locking portion for fixing the seed crystal. 8. The method of claim 7,
And the locking portion extends in a direction perpendicular to a direction in which the support extends. The method of claim 1,
The seed crystal support is a seed crystal fixing device movable in the vertical direction. A crucible for accommodating raw materials; And
An ingot manufacturing apparatus, which is located above the crucible and comprises a seed crystal fixing device according to any one of claims 1 to 9.

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