KR20210075612A - Heat shield for producing silicon single crystal ingot - Google Patents

Abstract

An inner plate of a thermal shield is disclosed. The inner plate of the thermal shield for preventing radiant heat inside a crucible from being transferred to a silicon single crystal ingot to grow the silicon single crystal ingot according to an embodiment can include: a cylindrical central part including a hollow; an upper part detachably connected to the upper end of the central part; and a lower part detachably connected to the lower end of the central part.

Description

Heat shield for silicon single crystal ingot production {HEAT SHIELD FOR PRODUCING SILICON SINGLE CRYSTAL INGOT}

The examples below relate to thermal shields used in silicon single crystal production.

One method for producing silicon single crystal ingots is the Czochralski method. The Czochralski method is a method in which a single crystal raw material to be grown is melted and then a seed single crystal is brought into contact with the melt to solidify the liquid and grow a single crystal.

In order to produce a silicon single crystal ingot, a thermal shield that prevents radiant heat emitted from the silicon melt from being transferred to the silicon single crystal ingot during the growth process is required. The thermal shield is an essential component for improving the productivity and quality of the silicon single crystal ingot, and a bottom plate positioned at the bottom of the crucible, and an inner plate and an outer plate positioned on the side are required.

In particular, since the inner plate blocks heat radiated directly from the crucible, a sufficient heat shielding function is required, so that a coating treatment for blocking heat needs to be performed on the surface. However, since the coating degree required for each part of the inner plate is different, an inner plate for a heat shield capable of more precise coating has been required.

An object according to an embodiment is to provide an inner plate for a heat shield that is easily removable.

An object according to an embodiment is to provide an inner plate for a heat shield that can be replaced by parts according to a design change.

In order to grow a silicon single crystal ingot according to an embodiment, the inner plate of the thermal shield for preventing the radiant heat inside the crucible from being transferred to the silicon single crystal ingot includes a cylindrical central part including a hollow; an upper part detachably connected to an upper end of the central part; and a lower part detachably connected to a lower end of the central part.

In one side, the upper part may include an upper inclined portion extending so as to sequentially increase in diameter from the upper end of the central part toward the upper side.

In one side, the upper part may further include a step portion extending outwardly from the upper end of the upper inclined portion.

In one side, the lower part may include a lower inclined portion extending so as to sequentially decrease in diameter from the lower end of the central part to the lower side.

In one side, the lower part may further include a lower extension extending in a vertical direction from a lower end of the lower inclined portion toward a lower side.

In one side, a first upper fastening member may be formed at an upper end of the central part, and a second upper fastening member capable of being fastened to the first upper fastening member may be formed at a lower end of the upper part.

In one side, a first lower fastening member may be formed at a lower end of the central part, and a second lower fastening member capable of being fastened to the first lower fastening member may be formed at an upper end of the lower part.

The inner plate for a heat shield according to an embodiment can be divided into a plurality of parts and can be separated, thereby reducing maintenance costs.

The inner plate for a heat shield according to an embodiment can be replaced by parts according to a design change.

Effects of the inner plate for thermal shielding according to an embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

The following drawings attached to this specification illustrate a preferred embodiment of the present invention, and serve to further understand the technical spirit of the present invention together with the detailed description of the present invention, so the present invention is limited to the matters described in those drawings It should not be construed as being limited.
1 is a perspective view of a thermal shield for a silicon single crystal ingot according to an embodiment.
2 is an exploded perspective view of a thermal shield for a silicon single crystal ingot according to an embodiment.
3 is a perspective view of an inner plate of a thermal shield according to an embodiment;
4 is a plan view of an inner plate of a thermal shield according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the embodiment, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and the essence, order, or order of the components are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but another component is between each component. It will be understood that may also be "connected", "coupled" or "connected".

Components included in one embodiment and components having a common function will be described using the same names in other embodiments. Unless otherwise stated, a description described in one embodiment may be applied to another embodiment, and a detailed description in the overlapping range will be omitted.

1 is a perspective view of a thermal shield for a silicon single crystal ingot according to an embodiment, and FIG. 2 is an exploded perspective view of the thermal shield for a silicon single crystal ingot according to an embodiment.

1 and 2 , a thermal shield according to an embodiment may be used in an apparatus for producing a silicon single crystal ingot. The silicon single crystal ingot production apparatus may include a chamber (not shown), a quartz crucible (not shown), a pedestal (not shown), a heater (not shown), and a heat shield.

The chamber may include an accommodation space therein. A passage through which the silicon single crystal ingot is moved may be formed above the chamber. The quartz crucible is disposed in an accommodating space inside the chamber, and polycrystalline silicon may be accommodated therein.

The pedestal supports the quartz crucible and can elevate or rotate the quartz crucible.

The heater is installed inside the chamber to surround the quartz crucible, and when power is applied, it can heat and melt polycrystalline silicon accommodated in the quartz crucible.

The thermal shield may be disposed on the upper side of the quartz crucible, and may prevent radiant heat of the silicon solution stored inside the quartz crucible from being transmitted to the silicon single crystal ingot.

When polycrystalline silicon is melted through a heater, a silicon solution is formed inside the quartz crucible. After immersing the seed crystals in the silicon solution, the silicon single crystal ingot grows through a predetermined process.

The thermal shield blocks the radiant heat emitted from the silicon solution from being transmitted to the growing silicon single crystal ingot during the silicon single crystal ingot growth process, thereby improving the quality of the silicon single crystal ingot. In other words, the thermal shield can directly affect the quality improvement and productivity increase of the silicon single crystal ingot.

The thermal shield may be installed to surround the silicon single crystal ingot. The heat shield may include a graphite material, and may include a bottom and a side surface. The thermal shield may include a bottom plate 30 constituting the bottom, an outer plate 20 constituting the outside of the side surface, and an inner plate 10 constituting the inside of the side surface.

The bottom plate 30 prevents radiant heat emitted from the silicon solution from being transferred to the silicon single crystal ingot, and a moving hole through which the silicon single crystal ingot passes may be formed in the center. The bottom plate 30 may be formed in an annular plate shape.

The outer peripheral surface of the bottom plate 30 is formed to be stepped, and the stepped outer peripheral surface may be engaged with the stepped surface at the lower end of the outer plate 20 to be described later. In addition, the moving port of the bottom plate 30 is formed to be stepped, and the inner circumferential surface of the moving port may be engaged with the stepped surface at the lower end of the inner plate 10 to be described later.

The outer plate 20 may include an outer body formed in a hollow cylindrical shape, and an extension portion extending upwardly from the upper end of the outer body and gradually expanding in diameter. A lower end of the outer body may extend toward the center of the outer body.

3 is a perspective view of the inner plate 10 of the thermal shield according to an embodiment, and FIG. 4 is a plan view of the inner plate 10 of the thermal shield according to an embodiment.

3 and 4 , the inner plate 10 may be disposed inside the outer plate 20 . The inner plate 10 may be divided into three parts separable from each other. The inner plate 10 includes a central part 100 , an upper part 110 detachably connected to an upper end of the central part 100 , and a lower part 120 detachably connected to a lower end of the central part 100 . ) may be included.

The central part 100 may be formed in a cylindrical shape including a hollow penetrating the inside in the vertical direction. The central part may have a circular cross-section having a constant diameter based on a cross-section parallel to the ground.

The upper part 110 may be connected to an upper end of the center part 100 . The upper part 110 may include an upper inclined portion 111 and a stepped portion 112 .

The upper inclined portion 111 may have a circular cross-sectional shape in which a diameter sequentially increases from the upper end of the central part 100 toward the upper side.

The step portion 112 may extend outward from the upper end of the upper inclined portion 111 in a horizontal direction. The outer edge of the step portion 112 may be in contact with the inner surface of the extension of the outer plate 20 . According to this structure, the relative position of the inner plate with respect to the outer plate can be aligned in a state where the inner plate is located inside the outer plate.

The lower part 120 may be connected to the lower end of the center part 100 . The lower part 120 may include a lower inclined portion 121 and a lower extension portion 122 .

The lower inclined portion 121 may have a circular cross-sectional shape extending so as to sequentially decrease in diameter from the lower end of the central part 100 to the lower side.

The lower extension part 122 may extend downwardly from the lower end of the lower inclined part 121 in a vertical direction. The lower end of the lower extension part 122 may be in contact with the bottom plate 30 . According to such a structure, the lower end of the inner plate may be supported by the bottom plate 30 .

The upper part 110 , the center part 100 , and the lower part 120 may be detachably fastened to each other. For example, a first upper fastening member 132 is formed at an upper end of the central part 100 , and a second upper fastening member 131 capable of being fastened to the first upper fastening member 132 at a lower end of the upper part 110 . ) can be formed. In addition, a first lower fastening member may be formed at a lower end of the central part 100 , and a second lower fastening member capable of being fastened to the first lower fastening member may be formed at an upper end of the lower part 120 .

Since the upper part 110 , the center part 100 , and the lower part 120 are connected to each other in a vertical direction, each of the fastening members fastened to each other may be formed in a shape to engage with each other. For example, the upper end of the first upper fastening member 132 includes a shape in which a part protrudes upward, and the lower end of the second upper fastening member 131 is the protruding upper end of the first upper fastening member 132 . It may be formed to be stepped in a shape to accommodate it. However, this shape is an example, and various types of fastening shapes that can be easily separated from each other may be applied.

Since the inner plate 10 is divided into three parts that are separable from each other, it is possible to replace each part as needed in the process of growing the silicon ingot. For example, when the inner plate is integrally configured, the entire inner plate has to be replaced when a partial design change is required depending on the ingot growth conditions, but in the case of the inner plate 10 according to an embodiment, only the parts requiring deformation are replaced. By doing so, it is possible to secure the effect of reducing the cost and time of replacing the inner plate 10 .

In particular, since the inner plate 10 is divided into three parts that are separated from each other, it is possible to treat the thermal insulation coating only on the central part 100 and the lower part 120, where heat is concentrated in the ingot growth, It can greatly reduce the time and cost required.

As described above, although the embodiments have been described with reference to the limited drawings, various modifications and variations are possible from the above description by those of ordinary skill in the art. For example, the described techniques are performed in an order different from the described method, and/or the described components of structures, devices, etc. are combined or combined in a different form than the described method, or other components or equivalents are used. Appropriate results can be achieved even if substituted or substituted by

10: inner plate
100: center part
110: upper part
120: lower part
20: outer plate
30: bottom plate

Claims (7)

In the inner plate of the thermal shield to prevent the radiant heat inside the crucible from being transferred to the silicon single crystal ingot to grow the silicon single crystal ingot,
a cylindrical central part including a hollow;
an upper part detachably connected to an upper end of the central part; and
and a lower part detachably connected to a lower end of the central part.
According to claim 1,
The upper part is
and an upper inclined portion extending from the upper end of the central part toward the upper side to sequentially increase in diameter.
3. The method of claim 2,
The upper part is
The inner plate of the thermal shield further comprising a step portion extending outwardly from the upper end of the upper inclined portion.
According to claim 1,
The lower part is
and a lower inclined portion extending downwardly in diameter from a lower end of the central part to sequentially decrease.
5. The method of claim 4,
The lower part is
The inner plate of the thermal shield further comprising a lower extension extending in a vertical direction downward from the lower end of the lower inclined portion.
According to claim 1,
A first upper fastening member is formed at an upper end of the central part, and a second upper fastening member capable of being fastened to the first upper fastening member is formed at a lower end of the upper part.
According to claim 1,
A first lower fastening member is formed at a lower end of the central part, and a second lower fastening member capable of being fastened to the first lower fastening member is formed at an upper end of the lower part.

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