KR20210089395A - Apparatus and method for growing silicon single crystal ingot - Google Patents

Abstract

An embodiment provides an apparatus for growing silicon single crystal ingot which comprises: a chamber; a crucible provided in the chamber and receiving a silicon molten liquid; a heating part provided in the chamber and arranged around the crucible; a first water cooling pipe provided to be fixed at an upper part of the inside of the chamber and arranged around the ingot grown to be raised from the crucible; a heat shielding body provided at an upper part of the crucible; and a mobile second water cooling pipe provided at an outer region of the first water cooling pipe. According to the present invention, productivity can be improved.

Description

Apparatus and method for growing a silicon single crystal ingot {APPARATUS AND METHOD FOR GROWING SILICON SINGLE CRYSTAL INGOT}

The embodiment relates to an apparatus for growing a silicon single crystal ingot, and more particularly, to an improvement of a water cooling tube of an apparatus for growing a silicon single crystal ingot.

A typical silicon wafer includes a single crystal growth process for making a single crystal (ingot), a cutting process for cutting a single crystal to obtain a thin disk-shaped wafer, and damage due to mechanical processing remaining on the wafer due to the cutting ( Damage), a polishing process for mirror-finishing the wafer, and a cleaning process for mirror-finishing the polished wafer and removing abrasives or foreign substances adhering to the wafer.

In the process of growing a silicon single crystal among the above-mentioned processes, the raw material is melted by heating a growth furnace charged with a high-purity silicon melt at a high temperature, and then grown by the Czochralski method (hereinafter referred to as the 'CZ' method). The method to be dealt with in this patent can be applied to the CZ method in which the seed crystal is positioned on top of the silicon melt to grow a single crystal.

In order to improve the productivity of the silicon single crystal ingot, the length of the basic section is increased. As the length of the silicon single crystal ingot increases, the initial charge is increased. However, since the existing water cooling tube is fixed to the chamber, the space of the upper hot zone, especially the heat shield, is limited, so that only a certain amount of polycrystalline silicon can be filled when filling the polycrystalline silicon lump in the crucible. Since the initial filling amount is limited, it is difficult to improve productivity.

In addition, in order to control the quality of crystal defects, it is necessary to change the cooling conditions of the silicon single crystal ingot. The cooling rate of the silicon single crystal ingot can be controlled by adjusting the relative position of the water cooling tube from the solid-liquid interface. As a method for adjusting the position of the water cooling tube, the position of the water cooling tube may be arbitrarily adjusted by using a shorter or longer length of the water cooling tube.

However, the method of adjusting the length of the water cooling tube has a disadvantage in that a plurality of water cooling tubes must be provided according to the length adjustment of the water cooling tube. In addition, when water cooling tubes having different lengths are used, it is inconvenient to replace the water cooling tubes whenever process conditions are changed. In the case of replacing such a water cooling tube or installing auxiliary equipment, the down time of the equipment is generated as much as the time, and productivity is reduced.

The embodiment is intended to solve the above-described problems, and to provide an apparatus and method for growing a silicon single crystal ingot with improved productivity during growth of the silicon single crystal ingot.

An embodiment is a chamber; a crucible provided in the chamber and accommodating a silicon melt; a heating unit provided in the chamber and disposed around the crucible; a first water cooling tube fixed to the upper portion of the chamber and disposed around the ingot grown and pulled up from the crucible; a heat shield provided on an upper portion of the crucible; and a movable second water cooling tube provided in an area outside the first water cooling tube.

The second water cooling tube and the heat shield may be raised and lowered in a direction parallel to the pulling direction of the ingot.

The silicon single crystal ingot growth apparatus may further include a driving unit provided at an upper portion of the chamber to elevate the second water cooling tube.

The driving unit may elevate the heat shield.

The driving unit may raise and lower the second water cooling tube and the heat shield in the same direction and at the same speed.

The lower end of the second water cooling tube may be elevated in the silicon melt direction from the lower end of the first water cooling tube.

The silicon single crystal ingot growth apparatus may further include a lifting shaft connecting the driving unit and the upper end of the heat shield.

The silicon single crystal ingot growth apparatus may further include a connection member connecting the upper end of the second water cooling tube and the lifting shaft.

A pair of driving units may be provided with an area in which the ingot is pulled therebetween.

Another embodiment includes the steps of (a) maximally increasing the distance between the silicon melt accommodated in the crucible and the heat shield; (b) supplying and melting polycrystalline silicon to the crucible; (c) reducing the distance between the silicon melt accommodated in the crucible and the heat shield to a minimum; and (d) dipping a seed into the silicon melt accommodated in the crucible, growing a silicon single crystal ingot, and pulling up the silicon single crystal ingot.

In step (a), the heat shield may be moved upward.

In step (c), the heat shield may be moved downward.

A first water cooling tube and a second water cooling tube are provided above the crucible and the heat shield, the first water cooling tube is fixed at the same position, and the second water cooling tube can move at the same speed and in the same direction as the heat shield .

In the apparatus and method for growing a silicon single crystal ingot, the water cooling tube is composed of a first water cooling tube and a second water cooling tube so that the length of the water cooling tube in the vertical direction is relatively short, thus, the conventional silicon single crystal ingot growth apparatus Even if a larger amount of polycrystalline silicon is supplied to the crucible than in the prior art using a larger tube and the amount or height of splashing of the silicon melt accommodated in the crucible increases, contamination of the heat shield due to splashing of the silicon melt does not occur, resulting in productivity This can be improved.

1 is a view showing an apparatus for growing a silicon single crystal ingot according to an embodiment;
2 is a view showing in detail the first and second water cooling tubes, the heat shield and the driving unit of FIG. 1;
3 is a view showing the movement of the second water cooling tube and the heat shield of FIG. 1;
Figure 4 is a view showing the effect of the silicon single crystal ingot growth apparatus according to the embodiment,
5 is a view showing an embodiment of a method for growing a silicon single crystal ingot according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings to help the understanding of the present invention by giving examples, and to explain the present invention in detail.

However, embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

Also, as used hereinafter, relational terms such as "first" and "second," "upper" and "lower", etc., shall not necessarily require or imply any physical or logical relationship or order between such entities or elements. In other words, it may be used only to distinguish one entity or element from another entity or element.

1 is a view showing an apparatus for growing a silicon single crystal ingot according to an embodiment. Hereinafter, an apparatus for growing a silicon single crystal ingot according to an embodiment will be described with reference to FIG. 1 .

As shown, the silicon single crystal ingot growth apparatus 1000 according to the embodiment is a chamber 100 in which a space for growing a silicon single crystal ingot from a silicon melt (Si melt) is formed therein, and the silicon Crucibles 200 and 250 for accommodating the Si melt, the heating unit 400 for heating the crucibles 200 and 250, and the heating unit 400 toward the silicon single crystal ingot Heat of A heat shield 500 positioned above the crucible 200 to block the seed chuck 10 for fixing a seed (not shown) for growth of a silicon single crystal ingot, and a crucible 250 . It is made to include a rotating shaft 330 for raising by rotating.

The grown silicon single crystal ingot may be lifted by the lifting unit 800 by the seed chuck 10. In order to cool the rising high temperature silicon single crystal ingot, the first water cooling tube 600 and the first water cooling tube Two water cooling tubes 650 may be disposed. The first water cooling pipe 600 is fixed to an upper region inside the chamber 100 , and the second water cooling pipe 650 is disposed outside the first water cooling pipe 600 . The second water cooling tube 650 and the heat shield 500 may be lifted at the same speed and in the same direction by the driving unit 700, that is, in the vertical direction in FIG. 2 , for example, in a direction parallel to the pulling direction of the silicon single crystal ingot. can be elevated to

The chamber 100 provides a space in which predetermined processes for forming a silicon single crystal ingot from a silicon melt (Si melt) are performed.

The crucibles 200 and 250 are provided inside the chamber 100 to contain a silicon melt, and may be made of a material such as quartz or graphite, but is not limited thereto.

The crucibles 200 and 250 may include a first crucible 200 that is in direct contact with the silicon melt, and a second crucible 250 that surrounds and supports the outer surface of the first crucible 200 . The first crucible 250 may be made of quartz, and the second crucible 250 may be made of graphite.

A heat insulating material may be provided in the chamber 100 to prevent the heat of the heating unit 400 from being emitted. In the present embodiment, only the heat shield 500 above the crucibles 200 and 250 is illustrated, but insulating materials may be disposed on the side and lower portions of the crucibles 200 and 250, respectively.

The heating unit 400 may melt polycrystalline silicon supplied in the crucibles 200 and 250 to make a silicon melt (Si melt), and the heating unit 400 receives a current from a current supply rod (not shown) disposed on the upper portion of the heating unit 400 . can be supplied.

A support 300 is disposed at the center of the bottom surface of the crucibles 200 and 250 to support the crucibles 200 and 250 . A silicon melt is partially solidified from the seed (not shown) on the crucibles 200 and 250 to grow a silicon single crystal ingot.

FIG. 2 is a view showing in detail the first and second water cooling tubes, the heat shield, and the driving unit of FIG. 1 .

The driving unit 700 may be provided above the chamber 100 , and may be, for example, a motor. A lifting shaft 750 may be vertically connected to the driving unit 700 , and the lifting shaft 750 may extend into the chamber 100 . The lifting shaft 750 may be connected to the upper end portion 500a of the heat shield 500 to move the heat shield 500 up and down.

A connecting member 680 is connected to a side surface of the upper end of the second water cooling tube 650 in a horizontal direction, and the connecting member 680 may be connected to the lifting shaft 750 .

In FIG. 2 , the lower end of the lifting shaft 750 is connected in contact with the upper end 500a of the heat shield 500 in the vertical direction, and the lower region of the lifting shaft 750 is the right end 680a of the connecting member 680 ). and can be connected by contacting in the horizontal direction.

The heat shield 500 , the first water cooling tube 600 , and the second water cooling tube 650 are respectively disposed to surround a region in which a silicon single crystal ingot is raised, and the driving unit 700 and the elevating shaft 750 are the chambers. (100) A pair is shown on the left and right of the upper part, and only one of each may be provided.

In FIG. 2 , a state in which the second water cooling tube 650 has moved the highest is shown, and the lower end 600a of the first water cooling tube 600 and the lower end 650a of the second water cooling tube 650 are located at the same height. can do. In a process to be described later, the lower end 650a of the second water cooling tube 650 may descend in the direction of the silicon melt at the same height as the lower end 600a of the first water cooling tube 600 .

The separation distance d1 between the outer surface of the first water cooling tube 600 and the inner surface of the second water cooling tube 650 may be 1 to 30 millimeters. If the separation distance d1 is less than 1 millimeter, it may interfere with the first water cooling tube 600 during the movement of the second water cooling tube 650, and if it is greater than 30 millimeters, the cooling effect of the silicon single crystal ingot decreases or Space utilization of the chamber 100 may be reduced.

The separation distance d2 in the vertical direction between the lower end 650a of the second water cooling tube 650 and the heat shield 500 may be 10 to 20 centimeters. If the separation distance d2 is less than 10 centimeters, there is a possibility that the second water cooling tube 650 and the heat shield 500 collide, and if it is greater than 20 centimeters, the cooling effect of the silicon single crystal ingot decreases or the chamber 100 space utilization may be reduced.

The length l1 in the vertical direction of the lifting shaft 750 may be variable, that is, when the length l1 of the lifting shaft 750 increases in the lower direction, the second water cooling tube 650 and the heat shield 500 . may move downward, and when it decreases upward, the second water cooling tube 650 and the heat shield 500 may move upward.

FIG. 3 is a view showing the movement of the second water cooling tube and the heat shield of FIG. 1 .

FIG. 3 shows a state in which the second water cooling tube 650 and the heat shield 500 have moved downward compared to FIGS. 1 and 2, for example, at the beginning of growth and pulling up of the silicon single crystal ingot. 650 and the first water cooling tube 600 form a long water cooling tube vertically. Accordingly, it is possible to efficiently cool the silicon single crystal ingot pulled into the first water cooling tube 600 and the second water cooling tube 650 .

In order to move the second water cooling tube 650 and the heat shield 500 , the length l2 of the elevating shaft 750 is increased than the length l1 of the elevating shaft 750 in FIG. 2 . Further, the lower end 650a of the second water cooling tube 650 is provided at a lower position than the lower end 600a of the first water cooling tube 600 , and the lower end 650a of the second water cooling tube 650 and the heat shield The separation distance d2 in the vertical direction from 500 may be the same as in FIG. 2 .

3 illustrates a state in which the second water cooling tube 650 and the heat shield 500 are moved to the lowest height. At this time, the height of the upper end 650b of the second water cooling tube 650 is the same as or higher than the height of the lower end 600a of the first water cooling tube 600 , and the first water cooling tube 600 and the second It allows the water cooling tube 650 to wrap around the entire height of the silicon single crystal ingot being pulled up.

4 is a view showing the effect of the silicon single crystal ingot growth apparatus according to the embodiment.

The left side shows the state in which polysilicon (Poly Si) is supplied to the crucible 200 to the conventional silicon single crystal ingot growth apparatus, and the right side shows the state of supplying polysilicon (Poly Si) to the silicon single crystal ingot growth apparatus according to an embodiment of the present invention. It shows a state in which Si) is supplied to the crucible 200 . A water cooling tube is shown by combining the first water cooling tube and the second water cooling tube on the right side.

In the conventional silicon single crystal ingot growth apparatus, when the tube is lowered and the valve is opened, polycrystalline silicon in the tube may be supplied into the crucible 200 . At this time, in order to prevent contamination of the heat shield 500 by splashing of the silicon melt accommodated in the crucible 200, the silicon melt and the heat shield 500 are spaced apart by a first distance D1. need to be

In the device for growing a silicon single crystal ingot according to the present invention on the right, the water cooling tube consists of the first water cooling tube and the second water cooling tube as described above, and the vertical length of the water cooling tube is relatively short. The silicon melt and the heat shield 500 are spaced apart by a second distance D2, and the second distance D2 is relatively larger than the first distance D1. Therefore, by using a tube larger than the conventional silicon single crystal ingot growth apparatus, a larger amount of polycrystalline silicon than before is supplied to the crucible 200 and the amount of splashing of the silicon melt accommodated in the crucible 200 to Even if the height is increased, contamination of the heat shield 500 by splashing of a silicon melt may not occur.

5 is a view showing an embodiment of a method for growing a silicon single crystal ingot according to the present invention, and shows a method for growing a silicon single crystal ingot using the above-described silicon single crystal ingot growth apparatus.

First, by raising the second water cooling tube and the heat shield, the distance between the silicon melt accommodated in the crucible and the heat shield is increased to the maximum (S110). The distance between the heat shield and the silicon aqueous solution may be the second distance D2 of FIG. 3 .

Then, after lowering the tube into which the polycrystalline silicon is injected into the upper part of the crucible (S120), the valve at the lower part of the tube is opened to inject the polycrystalline silicon into the crucible (S130).

Then, all of the polycrystalline silicon is melted by supplying heat to the crucible, and the tube is raised and taken out of the chamber (S140).

Then, after immersing a seed with the silicon melt of the crucible from the upper part of the chamber, a silicon single crystal ingot is grown (S150). At this time, by moving the second water cooling tube and the heat shield to the lower part, the first water cooling tube and the second water cooling tube are disposed in the entire area around the silicon single crystal ingot that is grown and pulled upward to cool the silicon single crystal ingot, and heat The distance between the shield and the silicon melt is smaller than in S110 above, so that the hot zone can be well maintained.

As described above, although the embodiment has been described with reference to the limited embodiment and the drawings, the present invention is not limited to the above embodiment, and those skilled in the art to which the present invention pertains various modifications and variations from these descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims as well as the claims and equivalents.

10: seed chuck 100: chamber
200, 250: crucible 300: support
400: heating unit 500: heat shield
600: first water cooling tube 650: second water cooling tube
680: connecting member 700: drive shaft
750: lifting shaft 800: lifting unit
1000: growth device for silicon single crystal ingot

Claims (13)

chamber;
a crucible provided in the chamber and accommodating a silicon melt;
a heating unit provided in the chamber and disposed around the crucible;
a first water cooling tube fixed to the upper portion of the chamber and disposed around the ingot grown and pulled up from the crucible;
a heat shield provided on an upper portion of the crucible; and
An apparatus for growing a silicon single crystal ingot including a movable second water cooling tube provided in an outer region of the first water cooling tube. According to claim 1,
The second water cooling tube and the heat shield are raised and lowered in a direction parallel to a pulling direction of the ingot. 3. The method of claim 2,
A silicon single crystal ingot growing apparatus provided at the upper portion of the chamber and further comprising a driving unit for elevating the second water cooling tube. 4. The method of claim 3,
The driving unit is an apparatus for growing a silicon single crystal ingot for raising and lowering the heat shield. 5. The method of claim 3 or 4,
The driving unit is an apparatus for growing a silicon single crystal ingot for raising and lowering the second water cooling tube and the heat shield in the same direction and at the same speed. According to claim 1,
A lower end portion of the second water cooling tube is raised and lowered in a direction of the silicon melt from a lower end portion of the first water cooling tube. 5. The method of claim 4,
The apparatus for growing a silicon single crystal ingot further comprising an elevating shaft connecting the driving unit and the upper end of the heat shield. 8. The method of claim 7,
The apparatus for growing a silicon single crystal ingot further comprising a connection member connecting the upper end of the second water cooling tube and the elevating shaft. 4. The method of claim 3,
The driving unit is an apparatus for growing a silicon single crystal ingot provided with a pair with a region in which the ingot is pulled therebetween. (a) maximally increasing the distance between the silicon melt accommodated in the crucible and the heat shield;
(b) supplying and melting polycrystalline silicon to the crucible;
(c) reducing the distance between the silicon melt accommodated in the crucible and the heat shield to a minimum; and
A method of manufacturing a silicon single crystal ingot comprising (d) dipping a seed into the silicon melt accommodated in the crucible, and growing and pulling the silicon single crystal ingot. 11. The method of claim 10,
In the step (a), a method of manufacturing a silicon single crystal ingot by moving the heat shield upward. 11. The method of claim 10,
In the step (c), a method of manufacturing a silicon single crystal ingot by moving the heat shield downward. 13. The method according to any one of claims 10 to 12,
A first water cooling tube and a second water cooling tube are provided above the crucible and the heat shield, the first water cooling tube being fixed at the same position, and the second water cooling tube moving at the same speed and in the same direction as the heat shield A method for manufacturing a silicon single crystal ingot.

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