KR20200059022A - Manufacturing apparatus for siliconcarbide single crystal and manufacturing method of siliconcarbide single crystal - Google Patents

Abstract

According to an embodiment of the present invention, a manufacturing apparatus of a silicon carbide single crystal comprises: a crucible including an outer circumferential surface; an induction heating type heating member surrounding the crucible; and an SiC seed crystal provided inside the crucible, wherein the crucible includes a protrusion located on the outer peripheral surface.

Description

Manufacturing apparatus and manufacturing method of silicon carbide single crystal {MANUFACTURING APPARATUS FOR SILICONCARBIDE SINGLE CRYSTAL AND MANUFACTURING METHOD OF SILICONCARBIDE SINGLE CRYSTAL}

The present invention relates to an apparatus for manufacturing a silicon carbide single crystal and a method for manufacturing a silicon carbide single crystal.

Silicon carbide (SiC) single crystal is widely used as a component material in the semiconductor, electronic, automotive, and mechanical fields due to its excellent mechanical strength such as wear resistance, heat resistance, and corrosion resistance.

For the growth of silicon carbide single crystals, for example, the Achison method of reacting carbon and silica in a high temperature electric furnace of 2000 degrees (° C) or higher, sublimation to grow single crystals by subliming at high temperature of 2000 degrees (℃) or higher using silicon carbide as a raw material And a solution growth method using a crystal pulling method. In addition, chemical vapor deposition using gas sources has been used.

However, the Achison method is very difficult to obtain a high-purity silicon carbide single crystal, and the chemical vapor deposition method may grow only at a limited level of the thickness of the thin film. Accordingly, research has been focused on a sublimation method of sublimating silicon carbide at high temperature to grow crystals. However, the sublimation method is also generally performed at a high temperature of 2400 ° C or higher, and there is a possibility that various defects such as micro-pipes and lamination defects are likely to occur, thereby limiting production cost.

The present invention is to provide an apparatus for manufacturing a silicon carbide single crystal and a method for manufacturing a silicon carbide single crystal to provide a required temperature distribution by selectively heating a specific region without a separate additional heat source.

In addition, the technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly understood by those skilled in the art from the following description. Will be understandable.

An apparatus for manufacturing a silicon carbide single crystal according to an embodiment of the present invention includes a crucible including an outer circumferential surface, an induction heating type heating member surrounding the crucible, and a SiC seed crystal provided inside the crucible, wherein the crucible is the outer circumferential surface It includes a protrusion located at.

The protrusion may include metal or graphite having electrical conductivity.

The diameter of the protrusion may be 101% to 120% of the diameter of the crucible.

The height of the protrusion may be 5% to 50% of the height of the crucible.

The protrusion may be detachable from the crucible.

The outer peripheral surface of the crucible may include a thread, and the protrusion may include an inner peripheral surface screwed to the thread.

The outer peripheral surface of the crucible may be cylindrical.

The diameter of the outer circumferential surface of the crucible may become smaller toward the bottom.

A method of manufacturing a silicon carbide single crystal according to an embodiment includes the steps of introducing an initial raw material containing silicon and metal into a crucible, heating the crucible using an induction heating heating member, and providing seed crystals in the crucible Including a step, in the step of heating the crucible, an outer circumferential surface of the crucible is heated by an induced current and an area where the protrusion is located is heated.

It may include the step of coupling the protrusion to the outer peripheral surface of the crucible.

The protrusion may move up and down along the outer circumferential surface of the crucible.

The height of the protrusion may be 5% to 50% of the height of the crucible.

According to the present invention, it is possible to provide an apparatus for manufacturing a silicon carbide single crystal and a method for manufacturing a silicon carbide single crystal having a required temperature distribution by selectively heating a specific region without a separate additional heat source.

1 is a schematic cross-sectional view of an apparatus for manufacturing a silicon carbide single crystal according to an embodiment.
2 is a schematic cross-sectional view of an apparatus for manufacturing a silicon carbide single crystal according to an embodiment.
3A is a perspective view of a crucible according to an embodiment, and FIG. 3B is a perspective view of a protrusion according to an embodiment.
4 is a temperature distribution graph and simulation image for Example 1.
5 is a temperature distribution graph and simulation image for Example 2.
6 is a temperature distribution graph and a simulation image for Comparative Example 1.
7 is a temperature distribution graph and a simulation image for Comparative Example 2.
8 is a temperature distribution graph and a simulation image for Comparative Example 3.
9 is a temperature distribution graph and a simulation image for Comparative Example 4.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present description, descriptions of already known functions or configurations will be omitted to clarify the subject matter of the present description.

In order to clearly describe the description, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification. In addition, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present description is not necessarily limited to what is illustrated.

In the drawings, the thickness is enlarged to clearly express the various layers and regions. In addition, in the drawings, thicknesses of some layers and regions are exaggerated for convenience of description. When a portion of a layer, film, region, plate, or the like is said to be "above" or "on" another portion, this includes not only the case where the other portion is "directly above" but also another portion in the middle.

An apparatus for manufacturing a silicon carbide single crystal and a method for manufacturing a silicon carbide single crystal according to an embodiment will be described with reference to FIG. 1. 1 is a schematic cross-sectional view of an apparatus for manufacturing a silicon carbide single crystal according to an embodiment.

Referring to FIG. 1, a silicon carbide single crystal manufacturing apparatus according to an embodiment heats a reaction chamber 100, a seed crystal 210 and a crucible 300, and a crucible 300 positioned inside the reaction chamber 100 It includes a heating member 400, a rotating member 500 for rotating the crucible 300.

The reaction chamber 100 is a closed shape including an empty interior space. The interior of the reaction chamber 100 may be maintained in an atmosphere such as constant pressure. Although not shown, a vacuum pump and a gas tank for controlling the atmosphere may be connected to the reaction chamber 100. After the inside of the reaction chamber 100 is vacuumed using a vacuum pump and a gas tank for controlling the atmosphere, an inert gas such as argon gas may be filled.

The silicon carbide seed crystal 210 is a portion where a silicon carbide single crystal is grown, and is located in an upper region inside the crucible 300. Depending on the manufacturing process, the bottom surface of the silicon carbide seed crystal 210 may be positioned to contact the surface of the melt located in the crucible 300.

The silicon carbide seed crystal 210 is made of a silicon carbide single crystal. The crystal structure of the silicon carbide seed crystal 210 is the same as that of the silicon carbide single crystal to be manufactured. For example, when manufacturing a 4H polycrystalline silicon carbide single crystal, the 4H polycrystalline silicon carbide seed crystal 210 may be used. When using the 4H polycrystalline silicon carbide seed crystal 210, the crystal growth plane is a (0001) plane or a (000-1) plane, or an angle of 8 degrees or less from the (0001) plane or (000-1) plane. It can be a photo side.

The seed crystal shaft 230 is formed to extend to be connected to the upper surface of the silicon carbide seed crystal 210 to support the silicon carbide seed crystal 210 and to allow the silicon carbide seed crystal 210 to be positioned inside the crucible 300. do.

The seed crystal shaft 230 may be connected to the seed crystal rotating rod 250 and rotated together, and the seed crystal shaft 230 may move up or down by the seed crystal rotating rod 250.

The crucible 300 is provided inside the reaction chamber 100 and may be in the form of an open container on the upper side, and may include an outer circumferential surface 310 and a lower surface 320 excluding the upper surface. However, any form for forming a silicon carbide single crystal is possible without limitation to the above-described form, and may include a cover covering the upper surface according to the manufacturing process. The crucible 300 may be accommodated by charging a molten raw material such as silicon or silicon carbide powder.

The outer peripheral surface 310 and the lower surface 320 of the crucible 300 may be made of a material containing carbon, such as graphite, graphite, and SiC. The outer circumferential surface 310 and the lower surface 320 of the crucible 300 including such a material may be utilized as a source of carbon raw materials. Alternatively, a crucible made of a ceramic material may be used without being limited thereto, and a material or a source for providing carbon may be separately provided.

The crucible 300 according to an embodiment may include a protrusion 330 positioned on the outer circumferential surface 310.

The protrusion 330 may include the same material as the outer circumferential surface 310 and the lower surface 320, and may include, for example, graphite material. Or, without being limited thereto, the protrusion 330 may include a material different from the outer circumferential surface 310 and the lower surface 320, and may include a conductive metal material.

The diameter of the protrusion 330 may be about 101% to about 120% of the diameter of the outer circumferential surface 310. In order for the protrusion 330 to be coupled to the outer circumferential surface 310 of the crucible 300, the diameter of the protrusion 330 may be larger than the diameter of the outer circumferential surface 310. In addition, when the diameter of the protrusion 330 is excessively large, effective heat transfer may be difficult, so the diameter of the protrusion 330 may be about 120% or less of the diameter of the outer circumferential surface 310.

The protrusion 330 is coupled on the outer circumferential surface 310 and may be located at any height. According to an embodiment, the protrusion 330 may be positioned at a height substantially equal to a surface of the melt M located inside the crucible 300 or at a lower height than the surface of the melt M. That is, the protrusion 330 may be disposed at any height overlapping the melt (M). This is to change the temperature distribution of the melt.

Although the present specification shows an embodiment in which the crucible 300 includes a single protrusion 330, the present invention is not limited thereto, and the crucible 300 may include a plurality of protrusions 330.

In addition, although the present specification has described a shape in which the protrusion 300 surrounds the outer circumferential surface 310 of the crucible 300, the present invention is not limited thereto and may have any shape such as being located only on a part of the outer circumferential surface 310.

The heating member 400 may heat the crucible 300 to melt or heat the material accommodated in the crucible 300. The heating member 400 may be located on the outer circumferential surface of the crucible 300, for example, may have a shape surrounding the outer circumferential surface of the crucible 300.

Although the present specification shows an embodiment in which the heating member 400 is located in the chamber 100, the present invention is not limited thereto, and the heating member 400 is located outside the chamber 100 while the outer circumferential surface 310 and protrusion of the crucible 300 It can surround 330.

The heating member 400 may be an induction heating type heating member. Specifically, the heating member 400 may include an induction coil and heat the crucible 300 by an induction heating method of heating the crucible 300 by flowing a high-frequency current through the induction coil. Since the resistance heating method is a method of heating the entire atmosphere in the chamber by a separate heating element, it may be difficult for the protrusion to change the temperature distribution inside the crucible outer circumferential surface or the melt.

The apparatus for manufacturing a silicon carbide single crystal according to an embodiment may further include a rotating member 500. The rotating member 500 is coupled to the lower surface of the crucible 300 to rotate the crucible 300. High-quality silicon carbide single crystal can be grown on the silicon carbide seed crystal 210 as it is possible to provide a melt having a uniform composition through rotation of the crucible 300.

Hereinafter, a production method for obtaining a silicon carbide single crystal using the above-described manufacturing apparatus for a silicon carbide single crystal will be described.

First, an initial molten raw material containing silicon and metal is introduced into the crucible 300. The initial molten raw material may be in the form of a powder or a chunk, but is not limited thereto.

The crucible 300 on which the initial molten raw material is mounted is heated using an induction heating type heating member 400 in an inert atmosphere such as argon gas. Upon heating, the initial molten raw material in the crucible 300 changes to a melt containing silicon and metal. As time progresses, the melt contains carbon introduced from the crucible 300. Depending on the embodiment, the initial molten raw material may include carbon.

After the next crucible 300 reaches a predetermined temperature, the temperature of the crucible 300 is maintained and silicon carbide single crystals may be deposited on the seed crystal 210 surface. This uses that the temperature of the seed crystal 210 is lower than the temperature of the melt in the crucible 300. When the silicon carbide becomes supersaturated near the seed crystal 210, a silicon carbide single crystal is grown on the seed crystal 210 using the supersaturation degree as a driving force. Without being limited thereto, crystal growth may be performed while gradually lowering the temperature of the crucible 300.

Meanwhile, according to an embodiment, the process of heating the crucible 300 includes heating the area where the protrusion 330 is located. Since the heating member 400 according to an embodiment is an induction heating type heating member, the region where the protrusion 330 is located receives more induction current than other outer circumferential surfaces 310, and the protrusion 330 is located without additional heating means. The temperature of the zone can be increased.

For example, when the protrusion 330 is positioned at the position as illustrated in FIG. 1, the temperature of the outer circumferential surface 310 may be lowered as it goes along the height direction relative to the outer circumferential surface 310. However, according to an exemplary embodiment, when the protrusion 330 located in the middle of the height direction is included, the temperature of the region where the protrusion 330 is disposed may be increased while reducing the phenomenon that the temperature decreases.

The driving force for growing a single crystal in a solution growth method for obtaining a silicon carbide single crystal is the formation of supersaturation in the melt by a temperature gradient. That is, not only the temperature gradient, but also where the hot and cold regions are located in the melt is important for stable growth. In particular, when a hot spot or a cold spot is formed at a specific location, it is possible to accelerate polycrystalline precipitation of silicon carbide or corrosion of the crucible, and it is difficult to obtain a single crystal of a desired shape. In addition, for precipitation of single crystals from seed crystals located on the surface of the melt, the lower part of the melt is maintained at a higher temperature than the upper part. However, the crucible 300 according to an embodiment may be easy to provide a required temperature distribution by including a protrusion 330 that can be disposed at a specific location.

According to an embodiment, since the inside of the crucible 300 can be additionally heated in a specific region without a separate additional heat source, it may be easy to satisfy a required temperature distribution.

Hereinafter, an apparatus for manufacturing a silicon carbide single crystal according to an embodiment will be described with reference to FIGS. 2 to 3B. 2 is a schematic cross-sectional view of an apparatus for manufacturing a silicon carbide single crystal according to an embodiment. 3A is a perspective view of a part of a crucible according to an embodiment, and FIG. 3B is a perspective view of a protrusion according to an embodiment. Descriptions of the same components as those described in the above-described embodiment may be omitted.

First, referring to FIG. 2, the crucible 300 according to an embodiment may include an outer circumferential surface 310, a lower surface 320 and a protrusion 330. At this time, the diameter of the outer circumferential surface 310 according to an embodiment may be smaller as it goes down to the bottom. The outer circumferential surface 310 may have a cup shape.

Although this specification has shown and described an embodiment in which the outer circumferential surface 310 of the crucible 300 is in the form of a cylinder or the bottom is an open cup, it is of course not limited thereto and can have various forms.

Referring to FIG. 3A, the outer circumferential surface 310 of the crucible 300 according to an embodiment may include a thread 310a. Also, as illustrated in FIG. 3B, the protrusion 330 according to an embodiment may include an inner circumferential surface for screwing to the thread 310a of the outer circumferential surface 310.

The protrusion 330 may be coupled to or separated from the outer circumferential surface 310 of the crucible 300. In addition, the protrusion 330 may move up and down along the thread 310a of the outer circumferential surface 310 of the crucible 300 and may be disposed at a position where additional temperature heating is required.

The apparatus for manufacturing a silicon carbide single crystal including the crucible 300 according to an embodiment may easily achieve a required temperature distribution by arranging protrusions at a position where additional heating is required even without adding a separate heat source.

Hereinafter, a temperature distribution in a crucible according to Examples and Comparative Examples will be described with reference to FIGS. 4 to 9. FIG. 4 is a temperature distribution graph and simulation image for Example 1, FIG. 5 is a temperature distribution graph and simulation image for Example 2, and FIG. 6 is a temperature distribution graph and simulation image for Comparative Example 1, and FIG. 7 Is a temperature distribution graph and simulation image for Comparative Example 2, FIG. 8 is a temperature distribution graph and simulation image for Comparative Example 3, and FIG. 9 is a temperature distribution graph and simulation image for Comparative Example 4.

First, referring to FIG. 4, when the protrusion 330 coupled to the outer circumferential surface 310 is included according to the first embodiment, it can be seen that there is some temperature rise near the region where the protrusion 330 is located. When heating using the induction heating type heating member 400 as shown in Figure 4, it was confirmed that the temperature change caused by the protrusion 330 occurs in the region where the protrusion 330 is located.

Referring to FIG. 5, in the case of including the protrusion 330 coupled on the outer circumferential surface 310 according to the second embodiment, even when the protrusion 330 is relatively positioned above the outer circumferential surface 310, the protrusion 330 It was confirmed that a temperature rise occurred in the region located. The second embodiment is also a case where the crucible is heated using the induction heating type heating member 400. According to this, it was confirmed that the temperature distribution of the melt can be controlled by arranging the protrusion 330 at a specific position and heating it using the induction heating type heating member 400.

Referring to FIG. 6, in Comparative Example 1, which does not include a separate protrusion, even when heating the outer circumferential surface 310 of the crucible using the induction heating type heating member 400, the temperature decreases toward the top from the bottom of the crucible. Confirmed. In particular, when comparing Comparative Example 1 of FIG. 6 with Example 1 of FIG. 4, it can be seen that the temperature of the outer circumferential surface 310 is significantly reduced compared to the region in which the protrusion 330 is located in FIG. 4.

Next, FIG. 7 is a simulation image of Comparative Example 2 using a resistance-heating heating member without including a separate protrusion. Similar to Comparative Example 1, it was confirmed that the temperature of the outer circumferential surface decreases from the bottom of the crucible toward the top.

8 is a simulation image and a temperature distribution graph when the protrusion 330 coupled to the outer circumferential surface 310 is heated using a resistance heating type heating member. As shown in FIG. 8, even when the crucible includes the protruding portion 330, when heating the crucible using the resistance heating type heating member, it was confirmed that the temperature rise did not occur in the region where the protruding portion 330 is located.

FIG. 9 is a simulation image when a protrusion 330 coupled to an upper side of the crucible is circumferentially coupled and heated using a resistance-heating heating member. As shown in FIG. 9, it was confirmed that even if the crucible includes the protrusion 330, there is no noticeable temperature change for Comparative Example 1 without the protrusion. That is, it was confirmed that, when a resistance heating type heating member was used, it exhibited the same temperature change pattern as a cylindrical crucible regardless of whether a protrusion was included.

The apparatus for manufacturing a silicon carbide single crystal according to an embodiment includes an induction heating type heating member, and includes a protrusion located on an outer circumferential surface of the crucible, so that temperature control can be performed without a separate additional heat source.

In the foregoing, although specific embodiments of the present invention have been described and illustrated, the present invention is not limited to the described embodiments, and it is common knowledge in the field of this technology that various modifications and modifications can be made without departing from the spirit and scope of the present invention. It is obvious to those who have it. Therefore, such modifications or variations should not be individually understood from the technical spirit or viewpoint of the present invention, and the modified embodiments should belong to the claims of the present invention.

300: crucible
310: outer peripheral surface
330: protrusion
400: heating member

Claims (14)

Crucible including the outer peripheral surface,
An induction heating heating element surrounding the crucible, and
SiC seed crystal provided inside the crucible,
The crucible is a silicon carbide single crystal manufacturing apparatus including a protrusion located on the outer peripheral surface. In claim 1,
The protrusion is an apparatus for producing a silicon carbide single crystal containing metal or graphite. In claim 1,
The diameter of the protrusion is 101% to 120% of the diameter of the outer circumferential surface of the crucible. In claim 1,
The height of the protrusion is 5% to 50% of the height of the crucible silicon carbide single crystal manufacturing apparatus. In claim 1,
The protrusion is a device for manufacturing a silicon carbide single crystal detachable from the crucible. In claim 5,
The outer peripheral surface of the crucible includes a thread,
The protrusion is a silicon carbide single crystal manufacturing apparatus including an inner circumferential surface that is screwed to the thread. In claim 1,
The outer peripheral surface of the crucible is a silicon carbide single crystal manufacturing apparatus. In claim 1,
The apparatus for manufacturing a silicon carbide single crystal whose diameter of the outer circumferential surface of the crucible becomes smaller toward the bottom. Injecting the initial raw material containing silicon and metal in the crucible,
Heating the crucible using an induction heating type heating member, and
Providing a seed crystal in the crucible,
In the step of heating the crucible, a method for producing a silicon carbide single crystal in which a region where a protrusion is located is heated. In claim 9,
A method for producing a single crystal of silicon carbide, comprising the step of coupling the protrusion to the outer circumferential surface of the crucible. In claim 10,
The protrusion is a method of manufacturing a silicon carbide single crystal that moves up and down along the outer circumferential surface of the crucible. In claim 9,
The protrusion is a method of manufacturing a silicon carbide single crystal containing a metal or graphite. In claim 9,
The diameter of the protrusion is 101% to 120% of the diameter of the outer circumferential surface of the crucible. In claim 9,
The height of the protrusion is 5% to 50% of the height of the crucible, a method for producing a silicon carbide single crystal.

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