KR20210020539A - Apparatus for removing suspended solids to grow single crystal ingots, single crystal ingot grower applying the apparatus and method thereof - Google Patents

Abstract

According to one embodiment of the present invention, provided is a device for removing a floating material for the single crystal ingot growth, which comprises: a mesh plate provided with a plurality of meshes which can filter the floating material of the silicon melt contained in the crucible; and a mesh plate driving unit provided on the upper side of the crucible and configured to elevate or rotate the mesh plate.

Description

TECHNICAL FIELD [Apparatus for removing suspended solids to grow single crystal ingots, single crystal ingot grower applying the apparatus and method thereof]

The present invention relates to an apparatus for removing suspended solids for growing a single crystal ingot, an apparatus for growing a single crystal ingot using the same, and a method thereof.

As silicon wafers for semiconductor device manufacturing have progressed, most of silicon wafers are manufactured from silicon single crystal ingots grown by the Czochralski (CZ) method.

In the CZ method, polysilicon is added to a crucible, the crucible is heated by a heater that is a graphite heating element, and then the seed crystal is brought into contact with the silicon melt formed as a result of melting, crystallization occurs at the interface, and the seed crystal is slowly pulled up while rotating By doing so, a silicon single crystal ingot having a desired diameter is grown.

Japanese Patent Application No. 2005-279979 (filed on September 27, 2009) discloses a single crystal silicon pulling device that prevents contamination of the silicon melt by falling particles from a heat shielding agent, and a method and device for preventing contamination of the silicon melt. .

According to the prior art, the generation of particles is minimized by controlling the amount of change in the flow rate of Ar gas, but it is not possible to remove particles that have already fallen into the silicon melt by some of the structures inside the chamber. Therefore, since particles such as carbon and metal may contaminate the silicon melt, there is a problem of deteriorating the quality of the single crystal ingot.

The present invention has been conceived to solve the problems of the prior art described above, and provides a single crystal ingot growth apparatus for growing a single crystal ingot capable of removing a floating substance in the form of particles dropped on a silicon melt, a single crystal ingot growth apparatus using the same, and a method thereof. There is a purpose.

A device for controlling a floating material for growing a single crystal ingot according to an embodiment of the present invention includes a mesh plate having a plurality of meshes capable of filtering the floating material of a silicon melt contained in a crucible; And a mesh plate driving unit provided on the upper side of the crucible and lifting or rotating the mesh plate.

The mesh plate has a disk shape smaller than the diameter of the crucible, and meshes of 3 mm or less may be uniformly provided, and may be made of a quartz material.

The mesh plate driving unit includes a lower seed chuck connected to the center of the mesh plate, an upper seed chuck to which an upper part of the lower seed chuck is detached, a cable on which an upper part of the upper seed chuck is suspended, and a drive motor for rotating or elevating the cable It may include.

The mesh plate may be provided with a hole having a size larger than that of the mesh, and at least two of the holes may be provided at a predetermined interval in the radial direction between the center and the outer circumference of the mesh plate, and the holes, It may be formed in a size of 6 cm or less.

The apparatus for growing a single crystal ingot according to an embodiment of the present invention may include the apparatus for removing suspended solids as described above.

A method of growing a single crystal ingot according to an embodiment of the present invention includes: a first step of confirming a position of a floating material in a silicon melt contained in a crucible; A second step of removing the floating material identified in the first step with a mesh plate having a plurality of meshes and at least one hole; And a third step of immersing the seed crystals in the silicon melt from which the suspended matter has been removed in the second step.

The second step includes a first process of positioning the hole of the mesh plate above the floating object, a second process of lowering the mesh plate when the hole of the mesh plate is located above the floating object, and the floating object When passing through the hole of the mesh plate, a third process of rotating the mesh plate by a set angle, and a fourth process of raising the mesh plate and filtering the floating material on the meshes of the mesh plate may be included.

In the first process, if the floating material is in a circumferential region in which the hole of the mesh plate is located, the mesh plate may be rotated until the hole of the mesh plate is located above the floating material.

In the first process, if the floating material is inside/outside the circumferential area in which the hole of the mesh plate is located, the crucible may be rotated until the hole of the mesh plate is located above the floating material.

According to the present invention, particles such as carbon and metal that have fallen into the silicon melt can be removed before proceeding with the single crystal ingot growth process using a mesh plate that is suspended upwardly or downwardly or rotatably.

Therefore, contamination of the silicon melt during the single crystal ingot growth process can be prevented, and the quality of the single crystal ingot can be improved.

1 is a side cross-sectional view showing an ingot growing apparatus according to an embodiment of the present invention.
2 is a view showing an apparatus for removing suspended solids according to an embodiment of the present invention.
3 is a flow chart showing an ingot growing method according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings with respect to the present embodiment will be described in detail.

1 is a side cross-sectional view showing an ingot growing apparatus according to an embodiment of the present invention, and FIG. 2 is a view showing a floating matter removing apparatus according to an embodiment of the present invention.

The single crystal ingot growing apparatus of the present invention rotates or lifts the chamber 110, which is a closed space, and the crucible 120 provided inside the chamber 110 as shown in FIGS. 1 to 2, and the crucible 120 A crucible driving unit 130 for driving, a heater 140 for heating the crucible 120, an insulating material 150 for preventing heat from the heater 140 from escaping to the outside, and a single crystal pulled from the crucible 120 It may include a heat shield member 160 for cooling the ingot, a seed chuck driving unit 170 for raising seed crystals, and a mesh plate 180 that can be lifted or rotated by the seed chuck driving unit 170. have.

The chamber 110 provides a predetermined closed space in which a single crystal ingot is grown, and various components may be mounted inside/outside.

The chamber 110 may be composed of a cylindrical body 111 in which various components are embedded, and a dome-shaped cover 112 coupled to the upper side of the body 111. The cover 112 performs an ingot growth process. An observable view port may be provided.

A pulling path 113 having a long cylindrical shape through which a single crystal ingot can be pulled may be provided on the upper side of the chamber 110.

The crucible 120 is provided inside the body 111, as a container containing the high-temperature silicon melt (M), and may be composed of a quartz crucible 121 and a graphite crucible 122 surrounding the quartz crucible 121. have.

The crucible driving unit 130 is provided under the crucible 120, and may rotate or lift the crucible 120 during the ingot growth process, and may include a driving shaft and a driving motor.

When the seed crystal is immersed in the silicon melt (M) and the crucible driving unit 130 slowly rotates the crucible 120, a single crystal grows around the seed crystal, and when the seed crystal is gradually pulled up, the diameter of the single crystal gradually increases and the single crystal ingot Can be grown. As the silicon melt M contained in the crucible 120 decreases as the ingot growth process proceeds, the crucible driving unit 130 gradually raises the crucible 120, and the height of the interface of the silicon melt M can be kept constant. .

That is, by controlling the operation of the crucible driving unit 130 as the ingot growth process proceeds, the rotational speed and the lifting speed of the crucible 120 may be controlled.

The heater 140 is a graphite heating element, is provided to be spaced around the crucible 120, and may heat the crucible 120. When the heater 140 is operated, the polysilicon contained in the crucible 120 may be liquefied into a silicon melt, and the temperature of the silicon melt may be controlled by controlling the operation of the heater 140.

The heat insulator 150 is provided on the inner circumferential surface of the main body 111 and is disposed so as to be spaced apart around the heater 140, thereby preventing heat from the heater 140 from escaping to the outside through the main body 111.

The heat shield member 160 is installed so as to be suspended above the crucible 120, and can directly cool the ingot grown from the high temperature silicon melt (M). The heat shield member 160 is made of a graphite material that can withstand high temperatures, and a cooling channel (not shown) may be provided therein.

The lower portion of the heat shield member 160 is disposed to wrap around the single crystal ingot grown from the silicon melt (M) contained in the crucible 120 at a predetermined interval, and to be installed to maintain a predetermined distance from the silicon melt (M) interface. I can.

The seed chuck driving unit 170 may be configured to suspend the seed crystal and immerse it in the silicon melt M contained in the crucible 120.

According to an embodiment, the seed chuck driving unit 170 includes a lower seed chuck 171 to which seed crystals are mounted, an upper seed chuck 172 to which the lower seed chuck 171 is attached, and an upper seed chuck 172 A hanging cable 173, a drum 174 around which the cable 173 is wound, and a drive motor 175 for rotating the drum 174 may be included, but are not limited thereto.

The seed crystal may be fastened to the lower part 171b of the lower seed chuck, or the mesh plate 180 to be described below may be fastened to the lower part 171b of the lower seed chuck, and may be mounted in various forms.

The lower seed chuck 171 may be interchangeably mounted on the upper seed chuck 172, and the upper part 171a of the lower seed chuck may be bolted to the lower part 172a of the upper seed chuck. Of course, the upper/lower seed chuck 171 and 172 may be integrally configured or may be configured to be fastened in other forms, but is not limited thereto.

As a form in which the upper end of the upper seed chuck 172 is suspended from the cable 173, the cable 173 extends to the outside through the impression furnace 113, and is wound around the drum 174 located outside the impression furnace 113. It can be provided in a form.

The drum 174 may be rotated by the drive motor 175, and as the cable 173 is wound around the drum 174, the upper and lower seed chucks 171 and 172 suspended from the cable 173 rise, and the cable 173 ) Is released from the drum 174, the upper/lower seed chuck 171 and 172 suspended from the cable 173 may descend.

The seed chuck may be rotated by using the drum 174 and the drive motor 175 or by adding other components, and a configuration for rotating the seed chuck is a known technique, and thus a detailed description thereof will be omitted.

The seed chuck driving unit 170 configured as described above may be viewed as a mesh plate driving unit capable of lifting or rotating by hanging the mesh plate 180 to be described below.

The mesh plate 180 is a tool for removing floating matter, which is a kind of foreign matter, such as a structure that has fallen on the silicon melt (M), and is composed of a disk shape in which a plurality of meshes 181 are arranged in a uniform shape. The size may be 3 mm or less smaller than the size of the particle.

Since the mesh plate 180 must be immersed in the silicon melt (M) contained in the crucible 120, the diameter of the mesh plate 180 must be configured to be smaller than the diameter of the crucible 120.

Even if the mesh plate 180 is immersed in the silicon melt (M), it does not contaminate the silicon melt and must be able to withstand high temperatures, so that the mesh plate 180 is preferably made of a quartz material.

As a use for moving the floating material of the silicon melt (M) from the lower side to the upper side of the mesh plate 180, the mesh plate 180 may be provided with holes (182a, 182b) having a size larger than that of the mesh 181

The inner hole 182a may be provided in the center of the mesh plate 180, the outer hole 182b may be provided on the outer periphery of the mesh plate 180, and the inner hole 182a and the outer hole 182b It may be provided to maintain a predetermined interval in the radial direction.

Even if some of the structures inside the chamber 110 fall off and float in the silicon melt (M), if the float is 6 cm or more, the quality of the ingot growth process may be greatly affected, and thus the ingot growth process cannot be performed.

That is, since the ingot growth process can be performed only when the floating material dropped into the silicon melt M is at least 6 cm or less, the size of the holes 182a and 182b is at least 6 cm in consideration of the size of the floating material in which the ingot growth process can proceed. It may be provided in the following sizes.

The mesh plate 180 configured as described above may be lifted or rotated while being mounted on the seed chuck driving unit 170 described above.

The center portion of the mesh plate 180 may be detachably mounted on the lower portion 171b of the lower seed chuck, or may be integrally configured. In addition, the lower seed chuck 171 on which the mesh plate 180 is mounted may be bolted (B) to the upper seed chuck 172.

Therefore, when the drive motor 175 is operated, the cable 173 is wound or unwound on the drum 174, and the upper/lower seed chuck 171 and 172 and the mesh plate 180 suspended from the cable 173 are raised or You can descend.

3 is a flowchart illustrating an ingot growing method according to an embodiment of the present invention.

According to the method for growing a single crystal ingot according to an embodiment of the present invention, the position of the floating material in the silicon melt can be checked and the relative position of the floating material and the hole in the mesh plate can be determined (see S1 and S2).

The camera photographs the silicon melt contained in the crucible through the viewporter of the chamber, and the position of the floating material of the silicon melt and the relative position of the hole of the mesh plate can be obtained from the image captured by the camera.

Of course, the mesh plate is suspended above the silicon melt contained in the crucible, before being dipped in the silicon melt, and the hole of the mesh plate may be either an inner hole or an outer hole.

If the float is located in the circumferential region where the hole of the mesh plate is located, the mesh plate can be rotated until the hole of the mesh plate is positioned above the float (see S3).

If the float is not located in the circumferential region where the hole of the mesh plate is located, the crucible can be rotated until the hole of the mesh plate is positioned above the float (see S4).

For example, if the floating material is located outside the inner hole of the mesh plate, as the crucible is rotated, the floating material is moved in the radial direction by centrifugal force, and the floating material may be located below the outer hole of the mesh plate.

Of course, in order to accurately position the floating material below the outer hole of the mesh plate, a process of rotating the mesh plate may be additionally performed until the outer hole of the mesh plate is positioned above the floating material, but is not limited thereto.

If the hole of the mesh plate is located above the floating object as described above, the mesh plate can be lowered to be immersed in the silicon melt (see S5).

When the float is moved to the upper side of the mesh plate through the hole of the mesh plate, the mesh plate can be rotated by a set angle, and then the mesh plate can be raised from the silicon melt (see S6, S7).

When the floating material is filtered on the meshes of the mesh plate, the seed crystal is immersed in a clean silicon melt from which the floating material has been removed, and a single crystal ingot growth process can be performed (see S8 and S9).

Even if some of the structures inside the chamber fall into the silicon melt, a mesh plate can be used to remove particles such as carbon and metal that have fallen into the silicon melt before proceeding with the single crystal ingot growth process, thus preventing contamination of the silicon melt. , It can improve the quality of single crystal ingot.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

110: chamber 120: crucible
130: crucible driving unit 140: heater
150: insulation 160: heat shield member
170: seed chuck driving unit 180: mesh plate
181: mesh 181a, 182b: hole

Claims (13)

A mesh plate provided with a plurality of meshes capable of filtering the suspension of the silicon melt contained in the crucible; And
A single crystal ingot growth floating material removal device comprising a; a mesh plate driving unit provided on the upper side of the crucible and lifting or rotating the mesh plate. The method of claim 1,
The mesh plate,
A device for removing suspended solids for growing a single crystal ingot having a disk shape smaller than the diameter of the crucible. The method of claim 1,
The mesh plate,
A device for removing suspended solids for growing single crystal ingots with uniform meshes of 3 mm or less. The method of claim 1,
The mesh plate,
A device for removing suspended solids for growing single crystal ingots made of quartz. The method of claim 1,
The mesh plate driving unit,
A lower seed chuck connected to the center of the mesh plate,
An upper seed chuck to which an upper part of the lower seed chuck is detached,
A cable on which the upper part of the upper seed chuck is suspended,
Single crystal ingot growth floating material removal device comprising a drive motor for rotating or elevating the cable. The method of claim 1,
The mesh plate,
Single crystal ingot growth floating material removal device provided with a hole having a size larger than that of the mesh. The method of claim 6,
The hole is,
A floating material removing device for growing a single crystal ingot, wherein at least two are provided at a predetermined interval in a radial direction between the center and the outer circumference of the mesh plate. The method of claim 7,
The hole is,
A device for removing suspended solids for growing single crystal ingots formed in a size of 6 cm or less. A single crystal ingot growing apparatus comprising the apparatus for removing suspended solids according to any one of claims 1 to 8. A first step of checking the position of the floating material in the silicon melt contained in the crucible;
A second step of removing the floating material identified in the first step with a mesh plate having a plurality of meshes and at least one hole; And
A method of growing a single crystal ingot comprising a third step of immersing the seed crystals in the silicon melt from which the suspended matter has been removed in the second step. The method of claim 10,
The second step,
A first process of positioning the hole of the mesh plate above the floating object,
A second process of lowering the mesh plate when the hole of the mesh plate is located above the floating object,
A third process of rotating the mesh plate by a set angle when the floating material passes through the hole of the mesh plate,
A method of growing a single crystal ingot comprising a fourth step of raising the mesh plate and filtering the floating matter on the meshes of the mesh plate. The method of claim 11,
The first process,
When the floating material is in a circumferential region in which the hole of the mesh plate is located, the single crystal ingot growing method is rotated until the hole of the mesh plate is located above the floating material. The method of claim 11,
The first process,
When the floating material is located inside/outside the circumferential region in which the hole of the mesh plate is located, the single crystal ingot growing method of rotating the crucible until the hole of the mesh plate is located above the floating material.

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