KR20130035137A - Apparatus for fabricating ingot - Google Patents

Abstract

PURPOSE: An ingot manufacturing device is provided to reduce a defect of a single crystal by uniformly moving a gas to a seed via a first filter part. CONSTITUTION: A crucible(100) receives a second raw material(132). The second raw material is located on a first raw material(130). A first filter part(120) is located between the first raw material and the second raw material. The first filter part selectively passes a specific element. The first raw material is separated from the second raw material.

Description

Ingot manufacturing equipment {APPARATUS FOR FABRICATING INGOT}

The present description relates to an ingot manufacturing apparatus.

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.

In the SiC single crystal growth, carbon impurities and contaminants generated from the raw material for SiC single crystal growth may flow into the single crystal, thereby causing defects in the single crystal. Therefore, there is a problem that the membrane is applied in the crucible, the application of such a membrane, the ingot growth rate can be lowered. In addition, the diameter may decrease due to thermal etching in the edge region of the ingot at the beginning of ingot growth, and the yield of the wafer having the largest diameter is limited due to the heterogeneous growth. In addition, since the temperature gradient of the horizontal portion of the seed crystals is large, the ingot has a convex shape, which may cause a decrease in yield and a decrease in quality of the ingot.

Embodiments can grow high quality single crystals.

Ingot manufacturing apparatus according to an embodiment, the crucible for receiving a first raw material and a second raw material located on the first raw material; And a first filter part positioned between the first raw material and the second raw material and selectively passing a specific component.

Ingot manufacturing apparatus according to an embodiment may include a first filter portion, the first filter portion is spaced apart from the surface of the first raw material, the second raw material may be located on the first filter portion. Therefore, a first gas room may be located between the second raw material and the seed crystal holder, and a second gas room may be located between the second raw material and the first raw material.

First, sublimation of the second raw material may occur in the first gas room. Due to the high temperature gradient between the second raw material and the seed crystal holder, the raw material may be exhausted from the lower part of the second raw material. Specifically, the raw materials move from the lower end of the high temperature to the upper end of the second raw material, and as a result, a dense and dense SiC layer is formed on the surface of the second raw material. Uniform sublimation may occur in the dense SiC layer.

Subsequently, the first raw material located below the second raw material again has a high temperature gradient with the seed crystal holder and continuously supplies the raw material. In the second gas room, the sublimed gas on the surface of the first raw material may be induced to condense broadly and homogeneously at the first filter load end. That is, a polycrystal may be grown on the surface of the first filter part positioned on the first raw material by sublimation of gas on the surface of the first raw material. That is, polycrystals may be grown on the surface of the first filter part facing the surface of the first raw material. The polycrystal may be supplied as a raw material. In addition, the polycrystal is capable of high quality ingot growth by providing a high purity raw material. The first raw material can supply a high purity raw material to the seed crystal holder by passing through the first filter part.

In the first gas room, the gas passing through the first filter part may be uniformly moved to the seed crystal over the entire surface. Therefore, a homogeneous, low defect single crystal can be grown from the seed crystal. In addition, it is possible to prevent the single crystal growing therefrom from having a central convex shape. Thereby, the said single crystal can be utilized more efficiently. That is, the yield of the wafer obtained from the single crystal can be increased.

1 is a cross-sectional view of the ingot production device according to the first embodiment.
FIG. 2 is an enlarged cross-sectional view of part A of FIG. 1.
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. FIG. 2 is an enlarged cross-sectional view of part A of FIG. 1.

Referring to FIG. 1, the ingot manufacturing apparatus 10 according to the first embodiment may include a crucible 100, a first raw material 130, a second raw material 132, a support part 150, and a first filter part 120. ), The top cover 140, the seed crystal holder 160, the heat insulating material 200, the quartz tube 400 and the heat generating induction portion 500.

The crucible 100 may accommodate the first raw material 130 and the second raw material 132.

The crucible 100 may have a cylindrical shape to accommodate the first raw material 130 and the second raw material 132.

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 first raw material 130 and the second raw material 132 may include silicon and carbon. Specifically, the first raw material 130 and the second raw material 132 may be a compound containing silicon, carbon, oxygen and hydrogen. The first raw material 130 and the second raw material 132 may be silicon carbide powder (SiC powder) or polycarbosilane (polycarbosilane).

The first raw material 130 and the second raw material 132 may be spaced apart. That is, the second raw material 132 may be located on the first raw material 130, and may be positioned to be spaced apart from the first raw material 130 by a predetermined distance.

Subsequently, the support part 150 may be located in the crucible 100. The support part 150 may be located along the inner surface of the crucible 100. The support part 150 may extend from the bottom surface of the crucible 100 to the position of the first filter part 120.

The support part 150 may support the first filter part 120. That is, the first filter part 120 may be located on the support part 150.

The support part 150 may have a ring shape having an inner diameter and an outer diameter. The support 150 may include graphite. The density of the support part 150 may correspond to the density of the crucible.

The thickness of the support part 150 may be 2 mm to 5 mm. When the thickness of the support part 150 is less than 2 mm, it may be difficult to stably position the first filter part 120 on the support part 150. In addition, when the thickness of the support part 150 exceeds 5 mm, the powder filling amount of the first raw material 130 located in the support part 150 may be reduced.

The length of the support part 150 may correspond to the sum of the thickness of the first raw material 130 and the thickness of the second gas room 112.

The support 150 may be configured to have a system having a plurality of raw materials, and the support 150 may be reused to reduce manufacturing costs.

Subsequently, the first filter part 120 may be located in the crucible 100. The first filter unit 120 may be located between the first raw material 130 and the second raw material 132. In detail, the first filter part 120 may be located on the support part 150, and may be located at a lower end of the second raw material 132. Therefore, the first filter unit 120 may be spaced apart from the surface of the first raw material 130. That is, since the first filter part 120 is positioned to span the support part 150, the first filter part 120 may have a predetermined distance from the surface of the first raw material 130.

The second raw material 132 may be located from an upper surface of the first filter part 120. Therefore, the second raw material 132 may be spaced apart from the first raw material 130 positioned from the bottom surface of the crucible 100.

The first gas room 111 may be located between the second raw material 132 and the seed crystal holder 160. The sublimed gas from the first raw material 130 or the second raw material 132 may move to the seed crystal holder 160 through the first gas room 111.

Subsequently, a second gas room 112 may be located between the first raw material 130 and the second raw material 132. Specifically, a second gas room 112 may be located between the first filter unit 120 and the first raw material 130. Sublimation of the first raw material 130 may occur in the second gas room 112.

The height of the second gas room 112 may be related to the amount of charge of the first raw material 130. That is, the height of the second gas room 112 may vary according to the charging height of the first raw material 130. When the first raw material 130 is fine powder, even if the first raw material 130 and the second raw material 132 is charged to the lower portion of the first filter unit 120, the volume of the raw material is reduced due to the single crystal growth. While the second gas room 112 may be generated.

Since the height of the second gas room 112 is related to the diffusion of the sublimation gas, it can be adjusted according to the process conditions. In this case, when the second gas room 112 is too low, the surface of the first raw material 130 and the lower portion of the first filter unit 120 may be attached during the process. However, as described above, when the first raw material 130 is fine powder, the surface of the first raw material 130 and the first filter part 120 may not be adhered to each other. When the second gas room 112 is too high, the amount of charge of the first raw material 130 and the second raw material 132 may be greatly increased, and growth behavior may be difficult to control. The height of the second gas room 112 may be determined in consideration of the size, structure and heating effect of the crucible 100.

Sublimation of the raw materials present in each gas room may occur through the first gas room 111 and the second gas room 112.

This will be described in detail as follows.

First, sublimation of the second raw material 132 may occur in the first gas room 111. The raw material may be exhausted from the lower portion of the second raw material 132 due to the high temperature gradient between the second raw material 132 and the seed crystal holder 160. In detail, in the second raw material 132, raw materials move from the lower end of the high temperature to the upper end, and as a result, a dense SiC layer having a high density is formed on the surface of the second raw material 132. Uniform sublimation may occur in the dense SiC layer.

Thereafter, the first raw material 130 positioned below the second raw material 132 again has a high temperature gradient with the seed crystal holder 160 and continuously supplies the raw material. In the second gas room 112, the gas sublimed on the surface of the first raw material 130 may be induced to condense broadly and homogeneously under the first filter part 120. That is, a polycrystal may be grown on the surface of the first filter unit 120 positioned on the first raw material 130 by sublimation of gas on the surface of the first raw material 130. That is, polycrystals may be grown on the surface of the first filter unit 120 facing the surface of the first raw material 130. The polycrystal may be supplied as a raw material. In addition, the polycrystal is capable of high quality ingot growth by providing a high purity raw material. In addition, the first raw material 130 may supply the high purity raw material to the seed crystal holder 160 by passing through the first filter part 120.

In the first gas room 111, the gas that has passed through the first filter part 120 may be uniformly moved to the seed crystal 170 entirely. Therefore, a homogeneous, low defect single crystal can be grown from the seed crystal 170. In addition, it is possible to prevent the single crystal growing therefrom from having a central convex shape. Thereby, the said single crystal can be utilized more efficiently. That is, the yield of the wafer obtained from the single crystal can be increased.

In FIG. 1, although the first gas room 111 and the second gas room 112 are formed with the first filter unit 120 interposed therebetween, the embodiment is not limited thereto. Therefore, the first filter unit 120 may be charged in plural and include a plurality of gas rooms.

Subsequently, the first filter part 120 may be porous. That is, the first filter unit 120 may include a plurality of pores 120a. Specifically, the first filter unit 120 may include inter-fiber pores, and the pore size may vary from 0.1 um to 300 um. In addition, the first filter unit 120 may include a fiber surface pore formed on the fiber surface.

Referring to FIG. 2, the pores 120a may filter carbon impurities and contaminants of a very small size. In addition, the first filter unit 120 may pass through SiC ₂ , Si ₂ C, and Si to move to the seed crystal 170.

The first filter part 120 may have a thickness T of 1 mm to 10 cm. The thickness T of the first filter unit 120 may be selected according to the size, scale and process conditions of the crucible 100. When the first filter part 120 has a thickness T of less than 1 mm, the thickness T may be too thin, so that durability may be greatly reduced and breakage may occur during the process. In addition, it may be difficult to serve to adsorb or trap the carbon impurities. When the first filter part 120 has a thickness T of more than 10 cm, the thickness T may be too thick to slow down the rate at which materials other than carbon impurities are transmitted. That is, the rate of permeation of silicon carbide gas for growing the single crystal may be slowed down. For this reason, the growth rate of a single crystal can be slowed down.

The first filter unit 120 may be fibrous.

Since the first filter part 120 is a fibrous continuous structure, necking (chemical bonding) between the fibers is made. Therefore, durability of the first filter unit 120 may be improved, and damage to the first filter unit 120 may be prevented during the single crystal growth process. In addition, the first filter unit 120 may be easily manipulated to improve process efficiency. In addition, the silicon carbide gas required for single crystal growth may be uniformly supplied to the seed crystal 170, and the supply amount per hour may be increased. Thereby, single crystal growth rate can be improved.

In detail, the first filter part 120 may be a fibrous membrane.

Since the first filter part 120 is fibrous, it may be manufactured by any one of a melt spinning method, a meltblown method, and an electrospinning method. That is, the first filter unit 120 may be implemented through fiber spinning, heat treatment of the loaded and stacked fibers. However, the embodiment is not limited thereto, and the fibrous first filter part 120 may be manufactured by various methods.

In addition, the first filter unit 120 may selectively pass a specific component. Specifically, the first filter unit 120 may adsorb carbon impurities and contaminants or trap impurities. That is, the pores 120a included in the first filter unit 120 may adsorb fine impurities and trap large particles of impurities between the pores 120a and the pores 120a. Therefore, carbon impurities generated from the first 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 first filter unit 120 may be a carbon-based membrane.

The carbon-based membrane may be prepared by compression molding and calcining graphite powder. The carbon-based membrane is excellent in durability, permeability and impurity filtration characteristics. Therefore, when the carbon-based membrane is used as the first filter unit 120, a high quality single crystal may be manufactured.

However, the embodiment is not limited thereto, and the first filter unit 120 may include various materials having excellent durability, permeability, and impurity filtration characteristics.

Although not shown in the drawing, the first filter unit 120 may include a first layer and a second layer positioned on the first layer. That is, the first filter unit 120 may be formed of a plurality of layers.

The pores included in the first layer and the second layer may have different sizes.

Specifically, the pores included in the first layer may be larger than the pores included in the second layer.

The first layer may filter large carbon particles and impurities present in the first raw material 130 at the initial stage of single crystal growth. The second layer may filter fine carbon impurities and various contaminants that have passed through the first layer.

The first filter unit 120 is composed of two layers, thereby minimizing the intrusion of impurities into the single crystal. In addition, it is possible to ensure the maximum gas permeability (gas permeability).

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 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 first raw material 130 and the second raw material 132, 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 includes a first raw material 130, a second raw material 132, and a third raw material 134 which are spaced apart from each other. And a third gas room 113, a fourth gas room 114, and a fifth gas room 115 positioned between them, and include a first filter part 120 and a second filter part 122. .

The first raw material 130 is located from the bottom surface of the crucible 100.

The second raw material 132 is located on the first raw material 130. The second raw material 132 is spaced apart from the first raw material 130.

The third raw material 134 is located on the second raw material 132. The third raw material 134 is spaced apart from the second raw material 132.

The third gas room 113 is positioned between the third raw material 134 and the seed crystal holder 160. In the third gas room 113, the sublimed gas may move to the seed crystal holder 160.

The fourth gas room 114 is positioned between the second raw material 132 and the third raw material 134. The fourth gas room 114 may be spaced apart by the second filter part 122 positioned between the second raw material 132 and the third raw material 134. The second filter part 122 is positioned on the support part 150.

The fifth gas room 115 is positioned between the first raw material 130 and the second raw material 132. The fifth gas room 115 may be spaced apart from the first filter part 120 positioned between the first raw material 130 and the second raw material 132. The first filter part 120 may be caught by a locking part of the support part 150.

Subsequently, the length of the support part 150 is the thickness of the first raw material 130, the thickness of the fifth gas room 115, the thickness of the first filter part 120, and the thickness of the second raw material 132. It may correspond to the sum of the thickness and the thickness of the fourth gas room 114.

In the ingot manufacturing apparatus 20 according to the second embodiment includes three gas rooms, it is possible to supply a high purity raw material. That is, a dense SiC layer is formed on each of the first raw material 130, the second raw material 132, and the third raw material 134, and the raw materials are filtered in the dense SiC layer to obtain a high purity raw material. Can be provided. Through this, the yield of the ingot can be improved, and high-quality single crystals can 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 (18)

A crucible containing a first raw material and a second raw material located on the first raw material; And
An ingot manufacturing apparatus, comprising a first filter unit positioned between the first raw material and the second raw material and selectively passing a specific component. The method of claim 1,
The first raw material and the second raw material is ingot manufacturing apparatus spaced apart. The method of claim 1,
Ingot manufacturing apparatus is located along the inner surface of the crucible, and including a support for supporting the first filter portion. The method of claim 3,
The support portion is an ingot manufacturing apparatus having a ring shape having an inner diameter and an outer diameter. The method of claim 3,
The support unit ingot manufacturing apparatus comprising graphite. The method of claim 3,
Ingot manufacturing apparatus of the support portion has a thickness of 2 mm to 5 mm. The method of claim 3,
Located on the top of the crucible, further comprising a holder for fixing the seed crystals,
A first gas room is located between the second raw material and the holder,
An ingot manufacturing apparatus, wherein a second gas room is positioned between the first raw material and the second raw material. The method of claim 7, wherein
The length of the support portion ingot manufacturing apparatus corresponding to the sum of the thickness of the first raw material and the thickness of the second gas room. The method of claim 1,
The ingot manufacturing apparatus of the first filter unit is located at the lower end of the second raw material. The method of claim 3,
Ingot manufacturing apparatus further comprising a third raw material located on the second raw material. The method of claim 10,
The second raw material and the third raw material ingot manufacturing apparatus spaced apart. The method of claim 10,
Located on the top of the crucible, further comprising a holder for fixing the seed crystals,
A third gas room is located between the third raw material and the holder,
A fourth gas room is located between the second raw material and the third raw material,
An ingot manufacturing apparatus, wherein a fifth gas room is positioned between the first raw material and the second raw material. The method of claim 10,
Ingot manufacturing apparatus further comprising a second filter portion located between the second raw material and the third raw material. The method of claim 13,
Ingot manufacturing apparatus, wherein the second filter portion is located on the support. The method of claim 13,
Ingot manufacturing apparatus of the first filter portion or the second filter portion comprises graphite. The method of claim 13,
The ingot manufacturing apparatus of the said 1st filter part or the said 2nd filter part is porous. The method of claim 13,
The apparatus for producing an ingot, wherein the first filter part or the second filter part comprises a membrane. The method of claim 13,
And a length of the support part corresponds to a sum of a thickness of the first raw material, a thickness of the fourth gas room, a thickness of the first filter part, a thickness of the second raw material, and a thickness of the fifth gas room.

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