KR20120135743A - Apparatus for fabricating ingot and method for providing material - Google Patents

Abstract

PURPOSE: An ingot manufacturing device and a method for providing raw materials are provided to increase consumption efficiency of raw materials by smoothly forming the sublimation of the raw materials by including a recess part. CONSTITUTION: A crucible(100) accepts raw materials(130). The raw materials comprise a recess part(132). The recess part has a depressed structure. The recess part is placed on the upper side of the raw materials. The inner side of the recess part slops.

Description

Ingot manufacturing apparatus and raw material supply method {APPARATUS FOR FABRICATING INGOT AND METHOD FOR PROVIDING MATERIAL}

The present disclosure relates to an ingot production device and a raw material providing method.

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.

In this single crystal growth, a temperature gradient is formed in the horizontal region of the raw material. The temperature gradient is formed according to the distance to the crucible. Therefore, the sublimation amount of the raw material is different. By the temperature gradient, the single crystal has a convex shape, and defects may occur in the single crystal.

Embodiments can grow high quality single crystals.

An ingot manufacturing apparatus according to an embodiment includes a crucible for accommodating a raw material, and the raw material includes a recess portion.

Raw material providing method according to the embodiment, the step of processing the raw material; And charging the raw material into the crucible.

The raw material included in the ingot manufacturing apparatus according to the embodiment may include a recess. Thereby, sublimation of the raw material located in the crucible center can occur smoothly. That is, sublimation of the raw material may occur evenly in the horizontal region. Specifically, by uniformizing the temperature gradient formed in the horizontal region of the raw material, it is possible to make the sublimation of the raw material located in the center and the outer portion uniform. Thereby, the single crystal manufactured from this can prevent that central part has convex shape. Therefore, a high quality single crystal can be obtained, and the yield of the wafer manufactured from the single crystal can also be improved.

In addition, the carbonization distribution according to the sublimation of the raw material, it is possible to increase the consumption efficiency of the raw material. Therefore, manufacturing cost can be reduced.

Raw material providing method according to the embodiment may include the step of pressing the raw material. By press-molding the raw material, the raw material can be processed without adding impurities to the raw material.

1 is a cross-sectional view of an ingot manufacturing apparatus according to an embodiment.
2 is a perspective view of a raw material included in an ingot manufacturing apparatus according to an embodiment.
3 is a process flowchart of a raw material providing method according to an embodiment.
4 is a perspective view illustrating a raw material providing method according to an 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 an Example is demonstrated in detail. 1 is a cross-sectional view of an ingot manufacturing apparatus according to an embodiment. 2 is a perspective view of a raw material included in an ingot manufacturing apparatus according to an embodiment.

1 and 2, the ingot manufacturing apparatus 10 according to the embodiment includes a crucible 100, a raw material 130, an upper cover 140, a seed crystal holder 170, a focusing tube 180, Insulation material 200, quartz tube 400 and the heat generating induction portion 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, the material to be applied on the graphite material, it is preferable to use a material that is chemically inert to silicon and hydrogen at the temperature at which the silicon carbide single crystal 190 is grown. 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).

Subsequently, the raw material 130 may include a recess 132.

The recess 132 may have a recessed structure. In FIGS. 1 and 2, the recess 132 is shown as having a recessed conical structure inverted, but the embodiment is not limited thereto. Accordingly, the recess 132 may have various recessed structures, such as a stepped shape and an inverted arch shape.

The recess 132 may have an inverted horn shape. In FIGS. 1 and 2, the recess 132 is inverted cone shape, but the embodiment is not limited thereto. Thus, it can be of various inverted horn shapes.

The inner side surface 131 of the recess 132 may be inclined. Specifically, the raw material 130 includes a central portion CA and an outer portion EA surrounding the central portion CA, and the inner side surface 131 of the recess 132 is the outer portion EA. ) May be inclined toward the central portion CA.

In addition, the volume of the recess 132 may be greater in the central portion CA than the outer portion EA. That is, the central portion CA may be recessed deeper than the outer portion EA.

The recess 132 may be located on an upper surface of the raw material 130.

As a result, the raw material 130 may be mainly located at the outer portion EA having a high temperature region close to the crucible 100 and a lower portion of the crucible 100. That is, the raw material 130 may be located at a portion where the sublimation of the raw material 130 occurs mainly by forming a high temperature region.

Conventionally, a temperature gradient is formed in the horizontal region of the raw material. The temperature gradient is formed according to the distance to the crucible 100. That is, the crucible 100 is self-heated by the heat generating induction part 500, and the raw material 130 positioned near the crucible 100, that is, the outer portion EA has a high temperature. However, the raw material 130 located relatively far from the crucible 100, that is, the central portion CA has a low temperature.

Therefore, the sublimation amount of the raw material 130 on the surface of the raw material 130 is different. Sublimation amount is large on the surface of the raw material 130 located in the outer portion EA, and sublimation is not efficiently performed on the surface of the raw material 130 located in the central portion CA. This temperature gradient becomes larger with time. This is due to the large amount of sublimation of the raw material 130 positioned in the outer portion EA, and thus the temperature of the outer portion EA due to graphitization of the raw material 130 positioned in the outer portion EA. Is higher. In addition, sintering of the raw material may proceed in the center CA and the center of the upper portion of the crucible having a small amount of sublimation. As a result, the consumption of raw materials may not be efficient.

In addition, due to the temperature gradient and the sublimation amount difference, the single crystal grows into a convex shape, and the yield of the wafer manufactured from the single crystal may be lowered.

However, in the present embodiment, since the raw material 130 includes the recess 132, sublimation of the raw material 130 positioned in the central portion CA may occur smoothly. That is, the sublimation of the raw material 130 may occur evenly in the horizontal region. Specifically, by uniformizing the temperature gradient formed in the horizontal region of the raw material 130, it is possible to equalize the sublimation of the raw material 130 located in the central portion CA and the outer portion (EA). Thereby, the single crystal 190 manufactured therefrom can be prevented from having a convex shape of the central portion. Therefore, a high quality single crystal 190 can be obtained, and the yield of the wafer manufactured from the single crystal 190 can be improved.

In addition, the carbonization distribution according to the even sublimation of the raw material 130, it is possible to increase the consumption efficiency of the raw material 130. Therefore, manufacturing cost can be reduced.

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 be sealed to allow a reaction to occur in the crucible 100.

The upper cover 140 may include graphite. However, the embodiment is not limited thereto, and the upper cover 140 may include a material having a melting point higher than the sublimation temperature of silicon carbide.

The seed crystal holder 170 is positioned at the lower end of the upper cover 140. That is, the seed crystal holder 170 is disposed on the raw material 130.

The seed crystal holder 170 may fix the seed crystal 190. The seed crystal holder 170 may include high density graphite.

Subsequently, 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 190. 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.

The center portion induction heated by the heat generation induction part 500 is formed at a position lower than the center 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. This temperature gradient causes sublimation of the silicon carbide raw material, and the sublimed silicon carbide gas moves to the surface of the seed crystal 190 having a relatively low temperature. As a result, the silicon carbide gas is recrystallized to grow into a single crystal.

3 and 4, the raw material providing method according to the embodiment will be described in detail. For the sake of clarity and simplicity, the same or very similar parts to those described above will be omitted, and the different parts will be described in detail.

3 is a process flowchart of a raw material providing method according to an embodiment. 4 is a perspective view illustrating a raw material providing method according to an embodiment.

Referring to FIG. 3, the raw material providing method according to the embodiment may include processing the raw material (ST100) and charging (ST200).

The processing step ST100 may include pressing the raw material 130. Referring to FIG. 4, the raw material 130 may be charged into a cavity 10, and a pressure may be applied to the raw material 130 with a plunger 20. In this case, the plunger 20 may have the same shape as the recess portion described above.

By pressing the raw material 130, the raw material 130 can be processed without adding impurities to the raw material 130.

The raw material 130 processed through the processing step ST100 may include a recess having a recessed structure.

The processed raw material 130 may be charged to the crucible constituting the ingot manufacturing apparatus. The ingot can then be produced.

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 (11)

Including a crucible to accommodate the raw material,
The raw material is an ingot manufacturing apparatus comprising a recess. The method of claim 1,
The recess part has an recessed structure. The method of claim 1,
The recess portion is an ingot manufacturing apparatus located on the upper surface of the raw material. The method of claim 1,
Ingot manufacturing apparatus in which the inner surface of the recess is inclined. The method of claim 1,
The recess is an ingot manufacturing apparatus having an inverted horn shape. The method of claim 1,
The interior of the crucible includes a central portion and an outer portion surrounding the central portion,
An ingot manufacturing apparatus, wherein a volume of the recess is greater than that of the outer portion. Processing the raw material; And
Raw material providing method comprising the step of charging the raw material into the crucible. The method of claim 7, wherein
The processing step of raw material providing method comprising the step of pressing the raw material. The method of claim 7, wherein
After the processing step, the raw material is a raw material providing method comprising a recess. 10. The method of claim 9,
The recess provides a raw material having a recessed structure. 10. The method of claim 9,
A raw material providing method in which the inner surface of the recess is inclined.

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