KR20120138111A - Apparatus for fabricating ingot and method for fabricating ingot - Google Patents

Abstract

PURPOSE: An ingot manufacturing apparatus and method are provided to grow a high quality single crystal by controlling the sublimation speed of a growth initial raw material through a temperature difference compensation unit. CONSTITUTION: A crucible(100) receives a raw material(130). A temperature difference compensation unit(120) is formed on the raw material. The temperature difference compensation unit comprises silicon carbide. The temperature difference compensation unit is pellet including the silicon carbide and silicon. The silicon comprises 5 weight% to 30 weight%.

Description

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

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

Ingot manufacturing apparatus according to the embodiment, the crucible for receiving the raw material; And a temperature difference compensative part positioned on the raw material, wherein the temperature difference compensative part includes silicon carbide.

Ingot manufacturing method according to the embodiment comprises the steps of manufacturing a temperature difference compensation unit; Charging the temperature difference compensative part and the raw material into a crucible; Forming pores in the temperature difference compensation unit; And growing the single crystal by sublimation of the raw material.

Ingot manufacturing apparatus according to the embodiment includes a temperature difference compensation unit. The temperature difference compensative part may be located on an entire surface of the raw material surface. As a result, the surface of the raw material can be kept flat, and foreign substances that can flow into the raw material can be blocked. In addition, the temperature difference compensative part is capable of high quality single crystal growth by controlling the sublimation rate of the initial growth material.

The temperature gradient formed in the horizontal region of the raw material can be formed uniformly. 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.

In addition, due to the temperature difference compensative part, since the raw material maintains a high temperature, the amount of sublimation increases, and the growth rate of the single crystal can be increased. This increase in growth rate can shorten the single crystal growth process time and reduce power consumption. In addition, the efficiency of using raw materials is increased.

In addition, the temperature difference compensation part may maintain or widen the distance between the raw material and the seed crystal due to the weight of the temperature difference compensation part. As a result, a temperature gradient formed on the upper and lower portions of the crucible can be made constant. Through this, the growth rate of the single crystal can be made constant, and high quality single crystal can be grown. In addition, the powder sintered body generated in the central region of the crucible may gradually descend to the lower portion of the crucible having a higher temperature due to the weight of the temperature difference compensative part. Through this, it is possible to induce more sublimation of the raw material to improve the consumption efficiency of the raw material.

1 is a cross-sectional view of an ingot manufacturing apparatus according to an embodiment.
2 is a process flowchart of an ingot manufacturing method according to an embodiment.
3 to 11 are cross-sectional views and perspective views for explaining the ingot manufacturing method 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. 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, 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.

Referring to FIG. 1, the ingot manufacturing apparatus 10 according to the embodiment may include a crucible 100, a temperature difference compensative part 120, an upper cover 142, a lower cover 144, a seed crystal holder 160, and a heat insulating material. 200, a quartz tube 400, and a 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 crucible 100 may include a locking portion (reference numeral 102 of FIG. 5, hereinafter the same). The locking portion 102 may protrude from the crucible 100. The catching part 102 may facilitate charging of the temperature difference compensative part 120 and the raw material 130. The locking part 102 may fix the temperature difference compensation part 120 when the temperature difference compensation part 120 is charged into the crucible 100. After fixing the temperature difference compensative part 120 and charging the raw material 130, the crucible 100 may be provided upside down. Therefore, when the single crystal is grown, the temperature difference compensative part 120 may be located below the locking part 102.

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) or polycarbosilane (polycarbosilane).

Subsequently, the temperature difference compensative part 120 may be located in the crucible 100. In detail, the temperature difference compensative part 120 may be located on the raw material 130. In addition, the temperature difference compensative part 120 may be located on the entire surface of the surface of the raw material 130. As a result, the surface of the raw material 130 may be kept flat, and foreign materials that may flow into the raw material may be blocked. In addition, the temperature difference compensation unit 120 controls the sublimation rate of the growth initial raw material 130, thereby enabling high quality single crystal growth.

The temperature difference compensative part 120 may include silicon carbide and silicon. The materials are materials that generate heat by themselves or transfer heat by the heat generating induction part 500. Therefore, the exemplary embodiment is not limited thereto, and the temperature difference compensative part 120 may include various materials capable of self-heating or heat transfer without deformation even at 2000 ° C. or higher.

Due to the temperature difference compensative part 120, since the raw material 130 maintains a high temperature, the amount of sublimation increases, thereby increasing the growth rate of the single crystal. This increase in growth rate can shorten the single crystal growth process time and reduce power consumption. In addition, the efficiency of using raw materials is increased.

The silicon may be included 5 wt% to 30 wt%. The silicon may sublime during ingot growth. Therefore, pores may be formed at the place where the silicon is located. Through the pores, the raw material 130 may be sublimed to grow single crystals.

When the silicon is included in more than 5% by weight, the pores formed by sublimation of the silicon is increased, the sublimation of the raw material 130 may occur smoothly. In addition, when the silicon is included in less than 30% by weight, through the pores, it is possible to prevent the phenomenon that the raw material 130 is rapidly evaporated at the beginning of ingot growth. Thereby, high quality single crystal can be grown.

The temperature difference compensative part 120 may have a density of 2.8 g / cm ² to 3.2 g / cm ² . When the density of the temperature difference compensative part 120 is less than 2.8 g / cm ² , pores may increase, which may make it difficult to control the sublimation behavior of the raw material 130. The temperature difference compensation unit 120 has a density of 3.2 g / cm ² If exceeded, theoretically impossible, so description is omitted.

The temperature difference compensative part 120 may have a thickness t of 1 mm to 30 mm. When the temperature difference compensative part 120 has a thickness t of less than 1 mm, it may be difficult to play a role of making the temperature gradient uniform. In addition, when the temperature difference compensative part 120 has a thickness t exceeding 30 mm, the sublimation rate of the raw material 130 may drop. However, the embodiment is not limited thereto, and the thickness of the temperature difference compensative part 120 may vary according to the size, structure, and process conditions of the crucible 100.

The temperature difference compensative part 120 may form a uniform temperature gradient in the horizontal region of the raw material 130. In detail, the crucible 100 may include a central area CA and an outer area EA surrounding the central area CA. The temperature difference compensative part 120 may maintain a uniform temperature by compensating for a temperature difference between the central area CA and the outer area EA. Therefore, the sublimation of the raw material 130 positioned in the central area CA may be smoother, and the sublimation of the raw material 130 located in the outer area EA may be limited. As a result, high-quality single crystals may be grown by minimizing growth of polycrystals formed at the outer portion of the seed crystal 170. In addition, the consumption efficiency of the raw material 130 may be increased, and the occurrence of defects in the single crystal may be minimized. In addition, the phenomenon that the sublimed silicon carbide gas is condensed again may be prevented, thereby increasing the supply speed of the silicon carbide gas.

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 generates heat by the heat generating induction part 500, and the raw material 130 located near the crucible 100, that is, the outer region EA has a high temperature. However, the raw material 130 positioned relatively far from the crucible 100, that is, located in the central area CA has a low temperature.

Therefore, the sublimation amount of the raw material 130 on the surface of the raw material 130 is different. The sublimation amount on the surface of the raw material 130 located in the outer area EA is large, and the sublimation amount on the surface of the raw material 130 located in the central area CA is relatively small. This temperature gradient becomes larger with time. Since the sublimation amount of the raw material 130 located in the outer area EA increases, the temperature of the outer area EA is caused by the graphitization of the raw material 130 located in the outer area EA. Is higher.

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

Subsequently, the temperature difference compensative part 120 may maintain or widen a constant distance between the raw material 130 and the seed crystal 170 due to the weight of the temperature difference compensative part 120. As a result, a temperature gradient formed on the upper and lower portions of the crucible 100 can be made constant. Conventionally, as a single crystal grows, the single crystal gradually approaches a gap with the raw material 130 having a high temperature region. Such temperature influence may affect the quality of the single crystal.

In the present embodiment, the temperature difference compensative part 120 may make the growth rate of the single crystal constant and grow a high quality single crystal. In addition, the powder sintered body generated in the central area CA of the crucible 100 may gradually descend to the lower portion of the crucible 100 having a higher temperature due to the weight of the temperature difference compensative part 120. Through this, it is possible to induce more sublimation of the raw material to improve the consumption efficiency of the raw material.

Subsequently, an upper cover 142 may be positioned on an upper portion of the crucible 100. The upper cover 142 may seal the crucible 100. The upper cover 142 may include graphite.

The lower cover 144 may be located below the crucible 100. The lower cover 144 may seal the crucible 100. The lower cover 144 may include graphite.

The seed crystal holder 160 is positioned at the lower end of the upper cover 142. 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 142. However, the embodiment is not limited thereto, and the seed crystal 170 may be directly attached to the upper cover 142.

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 and the crucible 100 may be heated by flowing a high frequency current through the high frequency induction coil. That is, the raw material 130 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, a method of manufacturing an ingot according to an embodiment will be described with reference to FIGS. 2 to 11. 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.

2 is a process flowchart of an ingot manufacturing method according to an embodiment. 3 to 11 are cross-sectional views and perspective views for explaining the ingot manufacturing method according to the embodiment.

Referring to FIG. 2, the ingot manufacturing method according to the embodiment includes a manufacturing step (ST100), a charging step (ST200), a forming step (ST300), and a growing step (ST400).

In the manufacturing step ST100, a temperature difference compensative part may be manufactured. The temperature difference compensative part may include silicon carbide and silicon.

Referring to FIG. 3, the manufacturing step ST100 may include sintering a raw material 122 including silicon carbide and silicon. In the sintering step, the raw material 122 may be sintered by applying temperature and pressure.

Subsequently, referring to FIG. 4, the temperature difference compensative part 120 may be completed after sintering.

Subsequently, in the charging step ST200, the temperature difference compensative part 120 may be charged into the crucible 100. Referring to FIG. 5, the inverted crucible 100 is prepared, and the temperature difference compensative part 120 is positioned in the inverted crucible 100. The crucible 100 may include a locking portion 102, such that the temperature difference compensative portion 120 may span the locking portion 102.

Subsequently, referring to FIG. 6, the raw material 130 may be charged onto the temperature difference compensative part 120.

Subsequently, referring to FIG. 7, the crucible 100 may be covered with a lower cover 144 to cover the crucible 100.

Subsequently, referring to FIG. 8, the upper cover 142 including the seed crystal holder 160 to which the seed crystal 170 is attached may be positioned on the top of the crucible 100. As a result, the crucible 100 may be completely sealed.

9 and 10, pores may be formed in the temperature difference compensative part 120 in the forming step ST300. When the crucible 100 is heated, the silicon included in the temperature difference compensative part 120 sublimes. Silicon included in the temperature difference compensative part 120 is sublimed to form pores in the temperature difference compensative part 120a as shown in FIG. 10.

Subsequently, referring to FIG. 11, in the growing step ST400, the raw material 130 may be sublimated through the temperature difference compensative part 120a including the pores. As a result, the single crystal 190 may be grown.

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 (14)

A crucible for accommodating raw materials; And
It includes a temperature difference compensation unit located on the raw material,
The temperature difference compensative part ingot manufacturing apparatus comprising silicon carbide. The method of claim 1,
The temperature difference compensative part is an ingot manufacturing apparatus which is a sintered body containing silicon carbide and silicon. The method of claim 2,
The silicon is ingot manufacturing apparatus containing 5% to 30% by weight. The method of claim 1,
The temperature difference compensation unit has an ingot manufacturing apparatus having a thickness of 1 mm to 30 mm. The method of claim 1,
The temperature difference compensative part ingot manufacturing apparatus having a density of 2.8 g / cm ² to 3.2 g / cm ² . The method of claim 1,
The temperature difference compensative part is an ingot manufacturing apparatus that is a heating element. The method of claim 1,
The temperature difference compensative part is an ingot manufacturing apparatus that is a heat transfer body. The method of claim 1,
The temperature difference compensating portion is an ingot manufacturing apparatus located on the entire surface of the raw material surface. The method of claim 1,
It includes a locking portion protruding in the crucible,
The locking portion is ingot manufacturing apparatus that can secure the temperature difference compensation portion when the temperature difference compensation portion is charged in the crucible. Manufacturing a temperature difference compensation unit;
Charging the temperature difference compensative part and the raw material into a crucible;
Forming pores in the temperature difference compensation unit; And
Ingot manufacturing method comprising the step of subliming the raw material to grow a single crystal. The method of claim 10,
The temperature difference compensative part ingot manufacturing method comprising silicon carbide and silicon. The method of claim 10,
The manufacturing step comprises the step of sintering silicon carbide and silicon. The method according to any one of claims 11 and 12,
The silicon is ingot manufacturing method comprising 5% to 30% by weight. The method of claim 10,
In the forming of the pores, ingot manufacturing method comprising the step of subliming the silicon included in the temperature difference compensation.

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