CN111663178A - Heat shield device for pulling single crystal and single crystal silicon production equipment - Google Patents

Abstract

The invention provides a heat shield device for Czochralski single crystals and monocrystalline silicon production equipment. The heat shield device for Czochralski single crystals comprises: an inner shield, which is arranged around the single crystal; and an outer shield, which is coaxially arranged on the a side of the inner screen away from the single crystal; and a flow guide channel embedded between the inner screen and the outer screen, and the flow guide channel is used for introducing working gas. The embodiments of the present invention can improve the growth rate of single crystal, and improve the yield and production efficiency of single crystal silicon.

Description

Heat shield device for Czochralski monocrystalline and monocrystalline silicon production equipment

technical field

The invention relates to the field of photovoltaic technology, in particular to a heat shield device for Czochralski monocrystalline and monocrystalline silicon production equipment.

Background technique

With the development of photovoltaic technology, the use of monocrystalline silicon is becoming more and more extensive. For example, silicon wafers made of monocrystalline silicon are used as the main constituent structure of cells. With the increase of photovoltaic installed capacity, the use of monocrystalline silicon wafers is also becoming more and more extensive.

In the prior art, single crystal silicon production equipment such as a single crystal furnace is often used to produce single crystal silicon. The specific production method is as follows: inert gas such as argon is introduced from the top of the single crystal furnace, and the silicon raw material in the crucible is heated. A single crystal silicon rod is grown and drawn from the liquid surface of the molten silicon, that is, the crystal growth liquid surface. In the process of pulling single crystal silicon, the working gas is introduced into the molten silicon surface in the quartz crucible from top to bottom.

However, in the process of introducing the working gas into the crucible from top to bottom, the working gas can easily flush the impurities on the inner wall of the single crystal furnace, or the impurities on other thermal field components such as the guide tube in the single crystal furnace into the single crystal furnace. In the crystal growth atmosphere, the lattice growth order of single crystal silicon may be destroyed, which will seriously lead to broken edges of single crystal silicon rods, thereby affecting the yield and production efficiency of single crystal silicon.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention has been proposed to provide a heat shield device for Czochralski single crystals and single crystal silicon production equipment which overcome the above problems or at least partially solve the above problems.

In order to solve the above problems, on the one hand, the present invention discloses a heat shield device for Czochralski single crystal, comprising:

Inner screen, for setting around single crystal;

an outer screen, coaxially disposed on a side of the inner screen away from the single crystal; and

A guide channel is embedded between the inner screen and the outer screen, and the guide channel is used for introducing working gas.

Optionally, the guide channel includes a plurality of air tubes, and the plurality of air tubes are equiangularly distributed around the central axis of the inner screen on the side away from the single crystal.

Optionally, all of the multiple air ducts are in contact with the inner screen.

Optionally, the air guide tube includes: a tube wall and an air guide channel located in the tube wall, and the introduced working gas flows through the air guide channel.

Optionally, the tube wall includes a first sub-tube wall, a second sub-tube wall, and a cooling interlayer disposed between the first sub-tube wall and the second sub-tube wall.

Optionally, the diversion channel further includes a plurality of air outlets communicating with the plurality of air conduits, and the plurality of air outlets are opposite to the single crystal growth liquid surface and surround the central axis of the inner screen. Equiangular distribution.

Optionally, the diversion channel further includes an air outlet pipe connected to the plurality of air conduits, and the plurality of air outlets are all opened in the air outlet pipe.

Optionally, the air outlet pipe is arranged coaxially with the inner screen, and on the central axis of the inner screen, the air outlet pipe is closer to the crystal than the inner screen and/or the outer screen. growth liquid.

On the other hand, the present invention also discloses a single crystal silicon production equipment, comprising:

a crucible for containing the crystal growth melt; and

In the above heat shield device for Czochralski single crystal, the heat shield device for Czochralski single crystal is arranged coaxially with the crucible.

Optionally, the single crystal silicon production equipment further includes a gas supply mechanism, and the gas supply mechanism is connected to the flow guide channel of the heat shield device for Czochralski single crystal.

The present invention includes the following advantages:

In the embodiment of the present invention, since the guide channel is embedded between the inner screen and the outer screen, the guide channel can be used to introduce working gas. In the process of crystalline silicon, the guide channel can guide the working gas into the single crystal growth liquid surface, quickly take away the latent heat of crystallization generated during single crystal crystallization, increase the longitudinal temperature gradient, and improve the growth rate of the single crystal. Moreover, since the guide channel is embedded between the inner screen and the outer screen, it can prevent the working gas from rushing the impurities on the inner screen into the single crystal production atmosphere and affecting the single crystal The lattice growth order, in turn, can further improve the yield and production efficiency of single crystal silicon.

Description of drawings

Fig. 1 is the structural representation of a kind of heat shield device for Czochralski single crystal of the present invention;

Fig. 2 is the structural representation of a kind of airway of the present invention;

Fig. 3 is the structural representation of a kind of air outlet pipe of the present invention;

Fig. 4 is the structural representation of a kind of single crystal production equipment of the present invention;

10-inner screen, 11-outer screen, 12-guide channel, 121-airway, 122-tube wall, 1221-first sub-tube wall, 1222-second sub-tube wall, 1223-cooling interlayer, 123-conducting Gas channel, 124 - gas outlet pipe, 1241 - gas outlet hole, 40 - crucible, 401 - crystal growth solution, 402 - single crystal, 41 - heat shield device for Czochralski single crystal.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1

Referring to FIG. 1 , there is shown a schematic structural diagram of a heat shield device for Czochralski single crystals of the present invention, which may specifically include:

The inner screen 10 is used for setting around the single crystal;

The outer screen 11 is coaxially arranged on the side of the inner screen 10 away from the single crystal; and

The guide channel 12 is embedded between the inner screen 10 and the outer screen 11, and the guide channel 12 can be used to introduce working gas.

In practical applications, the working gas may be an inert gas such as argon, and the single crystal may be a single crystal silicon product such as a single crystal silicon rod pulled by a Czochralski single crystal method.

In the embodiment of the present invention, since the guide channel 12 is embedded between the inner screen 10 and the outer screen 11, the guide channel 12 can be used to introduce the working gas. In this way, in the process of pulling single crystal silicon by the Czochralski method Among them, the diversion channel 12 can introduce the working gas into the single crystal growth liquid surface, quickly take away the latent heat of crystallization generated during single crystal crystallization, increase the longitudinal temperature gradient, and improve the growth rate of the single crystal. Moreover, since the guide channel 12 is embedded between the inner screen 10 and the outer screen 11, it can prevent the working gas from rushing the impurities on the inner screen 11 into the single crystal production atmosphere and affecting the lattice growth of the single crystal The order, in turn, can further improve the yield and production efficiency of monocrystalline silicon.

In an optional embodiment of the present invention, the diversion channel 12 may include a plurality of air tubes 121 , and the plurality of air tubes 121 are equiangularly distributed around the central axis of the inner screen 10 on the side away from the single crystal. In practical applications, under the condition that the plurality of gas ducts 121 are equiangularly distributed around the central axis of the inner screen 10 on the side away from the single crystal, the working gas can be uniformly introduced into the single crystal production equipment, improving the The distribution uniformity of the working gas in the single crystal silicon production equipment improves the heating uniformity of the single crystal.

It can be understood that, FIG. 1 only shows the case where the diversion channel 12 includes two air tubes 121 , and in practical applications, the number of air tubes 121 in the diversion channel 12 can also be other values, such as : 3, 5, or 6, etc. The number of the air guide tubes 121 may not be specifically limited in the embodiment of the present invention.

Preferably, the air duct 121 can be disposed close to the inner screen 10, so that the air duct 121 can guide the working gas into a position closer to the single crystal, thereby improving the heat dissipation effect of the working gas on the single crystal. Specifically, the plurality of air tubes 121 may all be in contact with the inner screen 10 to fix the air tubes 121 on the inner screen 10 .

In practical applications, since the air duct 121 is in contact with the inner screen 10 and the temperature of the inner screen 10 is relatively high, in order to improve the heat resistance of the air duct 121 and improve the service life of the air duct 121, the air duct 121 The material can be stainless steel. Specifically, since stainless steel has good heat resistance, corrosion resistance, and good processing performance, in the case where the material of the air duct 121 is stainless steel, the air duct 121 has relatively good heat resistance, Corrosion resistance, and good processability.

It can be understood that, in practical applications, the air guide tube 121 may also be made of other materials such as high temperature resistant engineering plastics, high temperature resistant inorganic materials, etc. The specific material of the air guide tube 121 may not be limited in the embodiment of the present invention.

Referring to FIG. 2 , a schematic structural diagram of an air guide tube of the present invention is shown. As shown in FIG. 2 , the air guide tube may include: a tube wall 122 and an air guide channel 123 located in the tube wall 122 . The working gas flows through the gas guide passage 123 .

In this embodiment of the present invention, the tube wall 122 may include a first sub-tube wall 1221, a second sub-tube wall 1222, and a cooling interlayer 1223 disposed between the first sub-tube wall 1221 and the second sub-tube wall 1222. In practice, In application, the cooling interlayer 1223 can be used for circulating cooling water to reduce the temperature of the air duct 121 and improve the service life of the air duct 121 .

In another optional embodiment of the present invention, the diversion channel 12 may further include a plurality of air outlets communicating with the plurality of air conduits 121 , and the plurality of air outlets are all opposite to the single crystal growth liquid surface, and It is equiangularly distributed around the central axis of the inner screen. In practical applications, since the multiple gas outlets are opposite to the single crystal growth liquid surface and are distributed equiangularly around the central axis of the inner screen, the working gas in the guide channel 12 can be uniformly introduced into the single crystal growth The liquid level is improved, the distribution uniformity of the working gas in the single crystal growth liquid level is improved, and the heating uniformity of the single crystal growth liquid level is improved.

In practical applications, one of the gas outlet holes may be provided in each of the plurality of air pipes 121 , and each of the gas outlet holes is opposite to the single crystal growth liquid level.

In yet another optional embodiment of the present invention, the diversion channel 12 may further include an air outlet pipe 124 connected to a plurality of air conduits 121 , and the plurality of air outlets are all opened in the air outlet pipe 124 .

Referring to FIG. 3 , a schematic structural diagram of an air outlet pipe of the present invention is shown. As shown in FIG. 3 , the air outlet pipe 124 is provided with a plurality of air outlet holes 1241 .

As shown in FIG. 3 , a plurality of gas outlet holes 1241 can be evenly distributed on the gas outlet pipe 124, so that the working gas in the gas outlet pipe 124 can be uniformly introduced into the single crystal growth liquid level, so as to improve the working gas in the single crystal growth liquid. The distribution uniformity in the growth liquid surface is improved, and the heating uniformity of the single crystal growth liquid surface is improved.

It can be understood that, FIG. 3 only shows the case where the air outlet pipe 124 is provided with 8 air outlet holes 1241 , and in practical applications, the number of the air outlet holes 1241 on the air outlet pipe 124 can also be other values. For example, the number of air outlet holes 1241 may also be 6, 10, or 12. The specific number of the air outlet holes 1241 on the air outlet pipe 124 may not be limited in the embodiment of the present invention.

In the embodiment of the present invention, the gas outlet pipe 124 and the inner screen 10 may be coaxially disposed, and the gas outlet pipe 124 is closer to the crystal growth than the inner screen 10 and/or the outer screen 11 on the central axis of the inner screen 10 . liquid level. In practical applications, since the gas outlet pipe 124 is closer to the crystal growth liquid surface than the inner screen 10 and/or the outer screen 11 , the gas outlet pipe 124 can directly guide the gas to the direction of the work in the guide channel 124 . In this way, on the one hand, the latent heat of crystallization generated during crystallization of the single crystal can be quickly taken away, the longitudinal temperature gradient can be increased, and the growth rate of the single crystal can be improved. Moreover, it can further prevent the impurity on the inner screen 11 from being flushed into the single crystal production atmosphere by the working gas to affect the lattice growth order of the single crystal, and further, the yield and production efficiency of the single crystal silicon can be further improved.

To sum up, the heat shield device for Czochralski monocrystalline according to the embodiment of the present invention at least includes the following advantages:

In the embodiment of the present invention, since the guide channel is embedded between the inner screen and the outer screen, the guide channel can be used to introduce working gas. In the process of crystalline silicon, the guide channel can guide the working gas into the single crystal growth liquid surface, quickly take away the latent heat of crystallization generated during single crystal crystallization, increase the longitudinal temperature gradient, and improve the growth rate of the single crystal. Moreover, since the guide channel is embedded between the inner screen and the outer screen, it can prevent the working gas from rushing the impurities on the inner screen into the single crystal production atmosphere and affecting the single crystal The lattice growth order, in turn, can further improve the yield and production efficiency of single crystal silicon.

Embodiment 2

Referring to FIG. 4 , a schematic structural diagram of a single crystal production equipment of the present invention is shown. As shown in FIG. 4 , the single crystal production equipment may specifically include: a crucible 40 , which can be used to accommodate a crystal growth melt 401 ; and the above-mentioned heat shield device 41 for Czochralski single crystals, the heat shield device 41 for Czochralski single crystals is arranged coaxially with the crucible 40 .

In practical applications, since the heat shield device 41 for Czochralski single crystals is coaxially arranged with the crucible 40 , the flow guiding channel on the heat shield device 41 for single crystals can work well when the single crystal silicon production equipment is pulling single crystals. The gas is introduced into the single crystal growth liquid level in the crucible 40 to quickly take away the latent heat of crystallization generated during the crystallization of the single crystal 402 , increase the longitudinal temperature gradient, and increase the growth rate of the single crystal 402 . Moreover, since the guide channel is embedded between the inner screen and the outer screen, it can prevent the working gas from rushing impurities on the inner screen into the single crystal production atmosphere and affecting the single crystal production atmosphere. The lattice growth order of the crystal 41, and thus, the yield and production efficiency of single crystal silicon can be further improved.

In practical applications, the single crystal silicon production equipment may further include a gas supply mechanism (not shown in the figure), and the gas supply mechanism is connected to the flow guide channel of the heat shield device 41 for Czochralski single crystals. In practical applications, the air supply mechanism can be used to provide working gas to the guide channel, and the air supply structure is connected to the guide channel of the Czochralski single crystal heat shield device 41, which can facilitate the guide channel to connect the The working gas in the gas supply mechanism is introduced into the single crystal production equipment.

In the single crystal silicon production equipment provided by the embodiment of the present invention, since the heat shield device 40 for Czochralski single crystal and the crucible 40 are coaxially arranged, the single crystal silicon production equipment uses the single crystal heat shield device 41 when pulling a single crystal. The guide channel on the top can guide the working gas into the single crystal growth liquid level in the crucible 40 , quickly take away the latent heat of crystallization generated when the single crystal 402 is crystallized, increase the longitudinal temperature gradient, and improve the growth rate of the single crystal 402 . Moreover, since the guide channel is embedded between the inner screen and the outer screen, it can prevent the working gas from rushing impurities on the inner screen into the single crystal production atmosphere and affecting the single crystal production atmosphere. The lattice growth order of the crystal 41, and thus, the yield and production efficiency of single crystal silicon can be further improved.

Finally, it should also be noted that in this document, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply these entities or that there is any such actual relationship or sequence between operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion such that a process, method, article or terminal device that includes a list of elements includes not only those elements, but also a non-exclusive list of elements. other elements, or also include elements inherent to such a process, method, article or terminal equipment. Without further limitation, an element defined by the phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

A heat shield device for Czochralski monocrystalline and monocrystalline silicon production equipment provided by the present invention have been introduced in detail above. Specific examples are used in this paper to illustrate the principles and implementations of the present invention. The description is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. , the contents of this specification should not be construed as limiting the invention.

Claims (10)

1. Heat shield device for pulling single crystal is characterized by comprising:

an inner screen for being disposed around the single crystal;

the outer screen is coaxially arranged on one side of the inner screen, which is far away from the single crystal; and

and the flow guide channel is embedded between the inner screen and the outer screen and is used for introducing working gas.

2. The heat shield apparatus for pulling a single crystal according to claim 1, wherein the flow guide channel comprises a plurality of gas-guiding tubes which are equiangularly distributed around a central axis of the inner shield on a side remote from the single crystal.

3. The heat shield apparatus for pulling a single crystal according to claim 2, wherein the plurality of gas-guiding tubes are in close contact with the inner shield.

4. The heat shield apparatus for pulling a single crystal according to claim 2, wherein the gas guide tube comprises: the gas guide device comprises a pipe wall and a gas guide channel positioned in the pipe wall, wherein the introduced working gas flows through the gas guide channel.

5. The heat shield apparatus for pulling a single crystal according to claim 4, wherein the tube wall comprises a first sub-tube wall, a second sub-tube wall, and a cooling jacket disposed between the first sub-tube wall and the second sub-tube wall.

6. The heat shield apparatus for pulling a single crystal according to any one of claims 2 to 5, wherein the flow guide passage further comprises a plurality of gas outlets communicating with the plurality of gas guide tubes, the plurality of gas outlets being opposed to the liquid surface of the single crystal growth and being equiangularly distributed around the central axis of the inner shield.

7. The heat shield apparatus for pulling a single crystal according to claim 6, wherein the guide passage further comprises an outlet tube connected to the plurality of gas guide tubes, and the plurality of gas outlets are provided in the outlet tube.

8. The heat shield apparatus for pulling a single crystal according to claim 7, wherein the gas outlet pipe is provided coaxially with the inner shield, and the gas outlet pipe is closer to the crystal growth liquid surface than the inner shield and/or the outer shield in the central axial direction of the inner shield.

9. Monocrystalline silicon production equipment, its characterized in that includes:

the crucible is used for accommodating crystal growth melt; and

the heat shield apparatus for Czochralski single crystal as set forth in any one of claims 1 to 8, which is disposed coaxially with the crucible.

10. The single-crystal silicon production apparatus according to claim 9, further comprising a gas supply mechanism connected to a flow guide passage of the heat shield device for pulling single crystal.

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