KR101818250B1 - Apparatus of ingot growing - Google Patents

Abstract

An ingot growing apparatus according to an embodiment includes: a chamber; A quartz crucible installed in the chamber and containing a silicon melt; A pulling mechanism for pulling up the ingot grown from the silicon melt; And a radiation shield positioned between the quartz crucible and the lifting mechanism; A first space between the radiation shield and the silicon melt; And a second space between the radiation shield and the quartz crucible, wherein there is a flow velocity difference between the first space and the gas flowing in the second space.

Description

[0001] APPARATUS OF INGOT GROWING [0002]

The present invention relates to an ingot growing apparatus.

Generally, a process for producing a wafer for manufacturing a semiconductor device includes a cutting process for slicing the silicon single crystal ingot, an edge grinding process for rounding the edge of the sliced wafer, a process for planarizing the rough surface of the wafer due to the cutting process A cleaning process to remove various contaminants such as particles attached to the wafer surface during the lapping process, the edge grinding or the lapping process, the surface grinding process for ensuring the shape and surface suitable for the post process, and the edge grinding process for the wafer edge can do.

The silicon monocrystalline ingot may grow through a czochralski (CZ) method or a floating zone (FZ) method. Generally, a silicon single crystal ingot with a large diameter can be produced and grown using a Czochralski method with low cost.

This Czochralski method can be achieved by immersing a seed crystal in a silicon melt and raising it at a low speed.

At this time, a radiation shield is used to control the characteristics of crystal defects and maintain a favorable atmosphere for crystal growth.

One of the advantages of using a radiation shield is the formation of a flow path for the argon gas on the surface of the silicon melt so that the flow of argon gas is relaxed and the oxide particles ), Thereby reducing the structural loss due to the introduction of oxide particles into the solid-liquid interface at which the single crystal grows. That is, the improvement of the crystallization yield was possible.

When a radiation shield is used, the flow path of argon gas is secured and the occurrence of the structural loss due to the introduction of oxide particles can be reduced. However, since each process condition is closely related to the quality of the grown crystal, At the same time, it is difficult to set a level at which the occurrence of the structural loss can be suppressed.

The embodiment can grow high-quality silicon ingots.

An ingot growing apparatus according to an embodiment includes: a chamber; A quartz crucible installed in the chamber and containing a silicon melt; A pulling mechanism for pulling up the ingot grown from the silicon melt; And a radiation shield positioned between the quartz crucible and the lifting mechanism; A first space between the radiation shield and the silicon melt; And a second space between the radiation shield and the quartz crucible, wherein there is a flow velocity difference between the first space and the gas flowing in the second space.

The ingot growing apparatus according to the embodiment can control the flow velocity difference of the argon gas flowing in the ingot growing apparatus. Therefore, the argon gas transports the impurities to the outside of the ingot growing apparatus, thereby eliminating the factors that cause the structural loss in the single crystal. As a result, the yield of the single crystal can be improved, and a single crystal of high quality can be produced.

Further, in this embodiment, the quality of the single crystal can be improved more easily by controlling the flow velocity difference.

1 is a cross-sectional view of a silicon single crystal ingot manufacturing apparatus according to an embodiment.
Fig. 2 is a graph of the flow velocity difference between the first and second spaces and the length of the single crystal.
3 is a graph of the structure loss and single crystal length.
FIG. 4 is a graph of the occurrence frequency of the structural loss. FIG.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under / under" Quot; includes all that is formed directly or through another layer. The criteria for top / bottom or bottom / bottom of each layer are 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.

The silicon single crystal ingot manufacturing apparatus according to the embodiment will be described in detail with reference to Fig. 1 is a cross-sectional view of a silicon single crystal ingot manufacturing apparatus according to an embodiment.

Referring to FIG. 1, the silicon single crystal ingot manufacturing apparatus according to the embodiment may be a manufacturing apparatus used in a czochralski (CZ) method among the methods of manufacturing a silicon wafer.

The silicon single crystal ingot manufacturing apparatus according to the embodiment includes a chamber 10, a quartz crucible 20 capable of containing a silicon melt (SM) 62, a crucible support 22, a crucible rotation shaft 24, The pulling mechanism 30, the radiation shield 40, the control unit 50, the resistance heater 70, the heat insulating material 80 and the magnetic field generating device 90 for pulling up the silicon single crystal ingot S, .

This will be described in more detail as follows.

1, a quartz crucible 20 is installed in the chamber 10, and a crucible support 22 supporting the quartz crucible 20 may be installed. A silicon melt (SM) is contained in the quartz crucible (20). The quartz crucible 20 may include quartz, and the crucible support 22 may include graphite.

The quartz crucible 20 can be rotated clockwise or counterclockwise by the crucible rotating shaft 24. A pulling mechanism 30 is attached to the upper portion of the quartz crucible 20 to attract and attract a seed crystal. The pulling mechanism 30 rotates in a direction opposite to the rotation direction of the crucible rotation shaft 24, can do.

The seed crystal attached to the lifting mechanism 30 is immersed in the silicon melt SM and then pulled up while rotating the pulling mechanism 30 to grow the silicon single crystal to produce the ingot S. Specifically, the process of growing the ingot S includes a necking step of growing an elongated single crystal, that is, a neck, from a seed crystal, a shouldering step of expanding the diameter from the neck to the target diameter, A body growth step of growing the silicon single crystal ingot in the axial direction while maintaining the target diameter, and a tailing step of separating the silicon single crystal ingot from the silicon melt (SM). The silicon single crystal ingot S having undergone such a growth process can be sliced into a wafer.

Next, a resistance heater 70 for heating the quartz crucible 20 adjacent to the crucible supporter 22 may be positioned. The heat insulating material 80 may be located outside the resistance heater 70. The resistance heater 30 melts polysilicon to supply the heat required to make the silicon melt SM, and continuously supplies the silicon melt SM in the manufacturing process.

Meanwhile, the silicon melt (SM) contained in the quartz crucible (20) emits heat at a high temperature and at the interface of the silicon melt (SM). At this time, when a large amount of heat is released, it is difficult to maintain the proper temperature of the silicon melt (SM) necessary for growing the silicon single crystal ingot (S). Therefore, it is necessary to minimize the heat emitted from the interface and prevent the released heat from being transmitted to the upper portion of the silicon single crystal ingot (S). For this purpose, a heat shield (not shown, hereinafter the same) may be provided so that the interface between the silicon melt (SM) and the silicon melt (SM) can maintain a high temperature environment.

The heat shield may have various shapes to maintain stable thermal growth by maintaining a desired thermal environment. For example, the heat shield may have a hollow cylindrical shape to surround the periphery of the silicon single crystal ingot S. The heat shield may include, for example, graphite, graphite felt, or molybdenum.

The radiating shield 40 may then be positioned between the quartz crucible 20 and the lifting mechanism 30. The radiation shield 40 may be a passage for gas flowing in the chamber 10. Further, the radiation shield 40 can control the temperature gradient of the ingot S to be grown.

A first space 52 may be located between the radiation shield 40 and the silicon melt SM. Also, a second space 54 may be located between the radiation shield 40 and the quartz crucible 20. The first space 52 and the second space 54 may be continuous.

Gas may flow through the first space 52 and the second space 54. The gas flows between the ingot S and the radiation shield 40 and flows through the first space 52 and the second space 54 into the quartz crucible 20 and the chamber 10 ). ≪ / RTI >

Specifically, the gas may be an inert gas. More specifically, the gas may include argon (Ar) gas.

Through the flow of the argon gas, silicon monoxide gas generated in the silicon melt (SM) and impurities existing in the ingot growing apparatus can be smoothly discharged to the outside of the ingot growing apparatus. If the impurities can not be discharged to the outside of the ingot growing apparatus, the impurities may flow into the silicon melt to cause a structure loss in the growing ingot, which may adversely affect the yield.

Therefore, it is important to control the gas flow. In particular, it is important to control the flow rate difference because the flow rate difference between the first space 52 and the second space 54 greatly affects the yield.

There may be a flow velocity difference between the gas flowing in the first space 52 and the gas in the second space 54. Specifically, the flow velocity difference may be 15 m / s or less. Preferably, the flow velocity difference may be less than or equal to 7 m / s.

If the flow velocity difference exceeds 15 m / s, the argon gas can not perform the role of transporting the impurities, which may increase the possibility of causing structural loss in the single crystal. When the flow velocity difference is 7 m / s or less, the argon gas carries impurities well, the possibility of occurrence of structural loss in the single crystal is reduced, and the yield of the single crystal can be improved. In addition, a single crystal of high quality can be produced.

In this embodiment, the quality of the single crystal can be improved more easily by controlling the flow velocity difference.

The control unit 50 may control the flow rate difference. Specifically, the controller 50 may include a first controller, a second controller, and a third controller.

The first control unit can control the flow rate difference by controlling the areas of the first space 52 and the second space 54. [ That is, the first control unit may control the area of the first space 52 and the second space 54 by adjusting the position of the radiation shield 40.

For example, in order to increase the flow rate in the first space 52, the area of the first space 52 can be narrowed. That is, it is possible to adjust the position of the radiation shield 40 so that the distance between the radiation shield 40 and the silicon melt SM becomes close to increase the flow rate in the first space 52. In contrast, the area of the first space 52 can be increased to slow the flow rate in the first space 52, that is, the distance between the radiation shield 40 and the silicon melt SM It is possible to adjust the position of the radiation shield 40 so that the flow rate in the first space 52 can be reduced. Thereby, the flow velocity difference can be controlled.

In order to increase the flow rate in the second space 54, the area of the second space 54 can be narrowed. That is, it is possible to adjust the position of the radiation shield 40 so that the distance between the radiation shield 40 and the quartz crucible 20 becomes close to increase the flow rate in the second space 54. The distance between the radiation shield 40 and the quartz crucible 20 can be increased in order to slow down the flow rate in the second space 54. On the contrary, It is possible to adjust the position of the radiation shield 40 so that the flow rate in the second space 54 can be reduced. Thereby, the flow velocity difference can be controlled.

The second control unit may control the flow rate difference by adjusting the amount of gas flowing in the first space 52 and the second space 54. That is, the second control unit can control the flow rate difference by further injecting or removing gas flowing in the first space 52 and the second space 54.

The third control unit may control the pressure in the chamber 10 to control the flow rate difference. That is, the third control unit can control the flow velocity difference by making the pressure in the chamber 10 higher or lower.

A magnetic field generating device 90 capable of controlling the convection of the silicon melt SM by applying a magnetic field to the silicon melt SM may be located outside the chamber 10. The magnetic field generating device 90 may be a device for generating a magnet field (MF) in a direction perpendicular to the crystal growth axis of the silicon single crystal ingot S.

2 to 4, the flow velocity difference between the first space 52 and the second space 54 and the number of times of occurrence of the structural loss are compared. Fig. 2 is a graph of the flow velocity difference between the first and second spaces and the length of the single crystal. 3 is a graph of the structure loss and single crystal length. FIG. 4 is a graph of the occurrence frequency of the structural loss. FIG.

Referring to FIG. 2, in case 1, the flow velocity difference between the first space 52 and the second space 54 does not exceed 7 m / s as the single crystal length becomes longer. Accordingly, referring to FIG. 3, it is determined that the number of occurrence of the structural loss in case 1 is almost zero.

On the other hand, referring to FIG. 2, in case 2, the single crystal length exceeds 1000 mm, the flow velocity difference exceeds 6 m / s, and referring to FIG. 3, Able to know.

That is, referring to FIG. 4, it can be seen that the frequency of occurrence of the structural loss increases as the flow velocity difference increases. Further, by maintaining the flow velocity difference at 7 m / s or less, the crystallization yield can be improved regardless of crystal growth conditions.

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. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in 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 and implemented. 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 (9)

chamber;
A quartz crucible installed in the chamber and containing a silicon melt;
A pulling mechanism for pulling up the ingot grown from the silicon melt; And
A radiation shield spaced apart from a sidewall of the quartz crucible in a sidewall of the quartz crucible and spaced apart from a surface of the silicon melt, the first space being defined by a distance between the radiation shield and the silicon melt, And a second space formed by the spacing between the side wall and the radiation shield,
Wherein a flow velocity of the gas flowing in the first space and a flow velocity difference of the gas flowing in the second space are 15 m / s or less. The method according to claim 1,
Wherein the flow velocity difference is not more than 7 m / s. The method according to claim 1,
And a control unit for controlling the flow rate difference. The method according to claim 1,
Wherein the gas comprises an inert gas. The method according to claim 1,
Wherein the gas comprises argon (Ar) gas. The method according to claim 1,
Wherein the first space and the second space are continuous. The method of claim 3,
Wherein the control unit includes a first control unit for controlling an area of the first space and the second space. The method of claim 3,
And the controller controls the amount of gas flowing in the first space and the second space. The method of claim 3,
Wherein the control unit includes a third control unit for controlling the pressure in the chamber.

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