Single crystal furnace

Abstract

The utility model is suitable for the technical field of single crystal furnaces, and provides a single crystal furnace. The single crystal furnace comprises a main chamber, an auxiliary chamber and a first flange, the main chamber and the auxiliary chamber are communicated together, the auxiliary chamber is arranged above the main chamber, a first air inlet is formed in the auxiliary chamber, the first flange is arranged on the auxiliary chamber, the first flange comprises a first air inlet hole and an inclined hole which are sequentially formed in the air inlet direction, and the first air inlet hole is communicated with the inclined hole; the inclined hole is connected with the first gas inlet, and the inclined hole is upwards inclined in the gas inlet direction. Thus, the first flange can be reused, inert gas can enter the auxiliary chamber through the first gas inlet hole and the inclined hole of the first flange, the inclined hole can effectively reduce vortex of the auxiliary chamber, impurities entering the area of the main chamber are reduced, and the production efficiency of monocrystalline silicon is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of single crystal furnaces, and in particular relates to a single crystal furnace. Background Art

[0002] The Czochralski single crystal furnace is a device that uses a graphite resistance heater to melt polysilicon raw materials in an inert gas environment and grows single crystals through the Czochralski method. In the existing Czochralski single crystal furnace gas path design, the upper protective gas flow is more likely to generate backflow in the auxiliary chamber furnace cavity, bringing impurities in the auxiliary chamber and valve chamber of the single crystal furnace into the silicon melt. The introduced impurities will directly lead to a significant increase in the shoulder breakage rate and equal diameter breakage rate during the single crystal silicon round rod pulling process, reducing the output and increasing the production cost of single crystal silicon. Utility Model Content

[0003] The embodiment of the utility model provides a single crystal furnace, which aims to solve the problem that the protective gas in the gas path of the single crystal furnace generates backflow in the auxiliary chamber furnace cavity, which directly leads to a significant increase in the shoulder breakage rate and the equal diameter breakage rate during the single crystal silicon round rod drawing process.

[0004] The embodiment of the utility model is implemented as follows: the utility model provides a single crystal furnace comprising: a main chamber and a sub-chamber connected together, the sub-chamber is arranged above the main chamber, and the sub-chamber is provided with a first air inlet; and

[0005] A first flange is arranged on the sub-chamber, and the first flange includes a first air inlet hole and an inclined hole arranged in sequence along the air inlet direction, the first air inlet hole and the inclined hole are communicated, and the inclined hole is connected to the first air inlet port, wherein the inclined hole is arranged to be inclined upward along the gas inlet direction.

[0006] Furthermore, the inclination angle of the inclined hole is 1° to 89°.

[0007] Furthermore, the first flange further includes a first annular space, and the first annular space is connected to the first air inlet hole and the inclined hole respectively.

[0008] Furthermore, the first annular space includes a first top surface, a first bottom surface, and a first inner side surface and a first outer side surface respectively connecting the first top surface and the first bottom surface, the inclined hole is connected to an end of the first inner side surface close to the first bottom surface, and the first air inlet hole is connected to the first outer side surface.

[0009] Furthermore, the first air inlet hole is arranged along the horizontal direction.

[0010] Furthermore, the single crystal furnace also includes a second flange, which is arranged on the main chamber, and the main chamber is also provided with a second air inlet. The second flange includes a second air inlet hole and a third air inlet hole, the second air inlet hole and the third air inlet hole are coaxially arranged, the second air inlet hole and the third air inlet hole are connected, and the third air inlet hole is connected to the second air inlet hole.

[0011] Furthermore, a third air inlet is provided on the main chamber, and the second flange also includes a fourth air inlet hole, the axis of the fourth air inlet hole intersects with the axis of the second air inlet hole, the second air inlet hole and the fourth air inlet hole are connected, and the fourth air inlet hole is connected to the third air inlet.

[0012] Furthermore, the second flange also includes a second annular space, and the second annular space is respectively connected to the second air inlet hole, the third air inlet hole and the fourth air inlet hole.

[0013] Furthermore, the second annular space includes a second top surface, a second bottom surface, and a second inner side surface and a second outer side surface respectively connecting the second top surface and the second bottom surface, the second air inlet hole is connected to the second outer side surface, the third air inlet hole is connected to the second inner side surface, and the fourth air inlet hole is connected to the second bottom surface.

[0014] Furthermore, the third air inlet is arranged along the vertical direction.

[0015] In the single crystal furnace of the embodiment of the present application, the single crystal furnace includes a main chamber and a sub-chamber connected together and a first flange, the sub-chamber is arranged above the main chamber, the sub-chamber is provided with a first air inlet, the first flange is arranged on the sub-chamber, the first flange includes a first air inlet hole and an inclined hole arranged in sequence along the air inlet direction, the first air inlet hole and the inclined hole are connected, the inclined hole is connected to the first air inlet, wherein the inclined hole is arranged upwardly inclined along the gas inlet direction. In this way, the first flange can be reused, the inert gas can enter the sub-chamber through the first air inlet hole and the inclined hole of the first flange, the inclined hole can effectively reduce the eddy current in the sub-chamber, thereby reducing the impurities entering the main chamber area, and improving the single crystal silicon production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a plan view of a single crystal furnace provided by an embodiment of the utility model;

[0017] Figure 2 It is a plan view of a first flange provided in an embodiment of the utility model;

[0018] Figure 3 is a cross-sectional view of a first flange provided in an embodiment of the utility model;

[0019] Figure 4is a plan view of a second flange provided in an embodiment of the utility model;

[0020] Figure 5 is another plan view of the second flange provided by an embodiment of the utility model;

[0021] Figure 6 It is a cross-sectional view of the second flange provided in the embodiment of the utility model.

[0022] Description of Figure Numbers:

[0023] 100. Single crystal furnace; 10. First flange; 11. First air inlet; 12. Inclined hole; 13. First annular space; 131. First top surface; 132. First bottom surface; 133. First inner side surface; 134. First outer side surface; 14. First inner annular wall; 15. First outer annular wall; 20. Second flange; 21. Second air inlet; 22. Third air inlet; 23. Fourth air inlet; 24. Second annular space; 241. Second top surface; 242. Second bottom surface; 243. Second inner side surface; 244. Second outer side surface; 25. Second inner annular wall; 26. Second outer annular wall; 27. Bottom wall; 30. Main chamber; 31. Second air inlet; 32. Third air inlet; 40. Sub-chamber; 41. First air inlet. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0025] The utility model provides a single crystal furnace, which includes a main chamber and a sub-chamber connected together and a first flange arranged on the sub-chamber, wherein the first flange includes a first air inlet hole and an inclined hole arranged in sequence along the air inlet direction, the inclined hole is connected to the first air inlet, wherein the inclined hole is arranged upwardly inclined along the gas inlet direction. In this way, the first flange can be reused, and the inert gas can enter the sub-chamber through the first air inlet hole and the inclined hole of the first flange, and the inclined hole can effectively reduce the eddy current in the sub-chamber, thereby reducing the impurities entering the main chamber area, and improving the single crystal silicon production efficiency.

[0026] Embodiment 1

[0027] Reference Figure 1 , Figure 2 and Figure 3The present embodiment provides a single crystal furnace 100 including: a main chamber 30, a sub-chamber 40 and a first flange 10. The main chamber 30 and the sub-chamber 40 are connected together. The sub-chamber 40 is arranged above the main chamber 30. The sub-chamber 40 is provided with a first air inlet 41. The first flange 10 is arranged on the sub-chamber 40. The first flange 10 includes a first air inlet hole 11 and an inclined hole 12 arranged in sequence along the air inlet direction. The first air inlet hole 11 is connected to the inclined hole 12, and the inclined hole 12 is connected to the first air inlet 41, wherein the inclined hole 12 is arranged to be inclined upward along the gas inlet direction.

[0028] In this embodiment, the specific type of the single crystal furnace 100 is not limited to meet different needs. For example, the single crystal furnace 100 can be a Czochralski single crystal furnace 100, which can melt polysilicon raw materials through a graphite resistance heater in an inert gas environment and grow single crystals through the Czochralski method. The Czochralski single crystal furnace 100 is used as an example below. Exemplarily, the single crystal furnace 100 of this embodiment can be divided into two upper and lower chambers, namely the main chamber 30 and the sub-chamber 40, the main chamber 30 and the sub-chamber 40 are separated by an isolation valve, the main chamber 30 and the sub-chamber 40 are respectively provided with an inert gas filling port, and the inert gas gas path is set to two paths. One path is the upper protective gas blown downward from the top of the sub-chamber; the other path is the lower protective gas blown in the opposite direction from the throat.

[0029] It is understandable that, since the distance between the sub-chamber 40 and the main chamber 30 is relatively long, the upper protective gas flow is more likely to reflux in the sub-chamber furnace, bringing impurities in the sub-chamber 40 and the valve chamber into the silicon melt. The introduced impurities will directly lead to a significant increase in the shoulder breakage rate and the equal diameter breakage rate during the drawing process of the single crystal silicon round rod, reducing the output, and thus causing a high production cost of single crystal silicon. In this embodiment, a first air inlet 41 is provided on the sub-chamber 40, and the first flange 10 is provided on the sub-chamber 40. The inert gas can pass through the first air inlet 11, the inclined hole 12 and the first air inlet 41 in sequence. Along the gas entry direction, the inclined hole 12 is arranged to be inclined upward. In this way, the first flange 10 can be reused, and the inert gas can enter the sub-chamber 40 through the first air inlet 11 and the inclined hole 12 of the first flange 10. The inclined hole 12 can effectively reduce the eddy current in the sub-chamber 40, thereby reducing the impurities brought into the silicon melt. The original upper protective gas is replaced by the protective gas to fill the sub-chamber 40 to normal pressure to isolate it separately for taking out rods or adding materials.

[0030] It should be noted that, in this embodiment, the sub-chamber 40 is cylindrical, the first flange 10 is annular, and the first flange 10 is concentrically sleeved on the sub-chamber 40 to ensure that the sub-chamber 40 is stably connected to the first flange 10. The first flange 10 can be formed with an annular groove, the inner diameter of the annular groove is the same as the inner diameter of the sub-chamber 40, so that the inclined hole 12 can be stably docked with the first air inlet 41, with high connection strength and good sealing to avoid leakage of inert gas. At the same time, the outer diameter of the first flange 10 can be the same as the outer diameter of the sub-chamber 40, or the outer diameter of the first flange 10 can be greater than the outer diameter of the sub-chamber 40, so that the outer ring of the first flange 10 protrudes relative to the sub-chamber 40, and the specific details are not limited here. In one example, when the outer diameter of the first flange 10 is the same as the outer diameter of the sub-chamber 40, the outer surface of the entire sub-chamber 40 is smooth, avoiding the inner diameter of the sub-chamber 40 being too small, restricting the maximum size of the single crystal round rod drawn, and improving stability.

[0031] In addition, in this embodiment, the specific type of the inert gas is not limited to meet different requirements. For example, the inert gas may be argon or nitrogen.

[0032] Embodiment 2

[0033] Reference Figure 3 On the basis of the above-mentioned embodiment 1, the second embodiment of the present invention provides a single crystal furnace 100, wherein the inclination angle of the inclined hole 12 is 1° to 89°. For example, the inclination angle of the inclined hole 12 can be 1°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 89°.

[0034] Specifically, the air intake direction of the first air intake hole 11 is horizontal, and the direction of the inclined hole 12 is inclined upward relative to the horizontal direction, and the inclination angle is 1° to 89°. In this way, when the inert gas enters the sub-chamber 40, the inclined hole 12 can guide the inert gas so that the inert gas can form a fixed loop in the sub-chamber 40, thereby reducing the vortex in the sub-chamber 40.

[0035] It is understandable that, corresponding to the sub-chambers 40 of different sizes and the different flow rates of the inert gas, the inclination angle and length of the inclined hole 12 need to be adjusted to minimize the occurrence of eddy currents. In one embodiment, the inclination angle of the inclined hole 12 is set to 45°, which can effectively reduce the eddy currents in the sub-chamber 40 and reduce the impurities brought into the silicon melt.

[0036] Embodiment 3

[0037] Reference Figure 2 and Figure 3On the basis of the above-mentioned second embodiment, the third embodiment of the present utility model provides a single crystal furnace 100, wherein the first flange 10 further includes a first annular space 13, and the first annular space 13 is connected to the first air inlet 11 and the inclined hole 12 respectively.

[0038] In addition, refer to Figure 4 The first annular space 13 includes a first top surface 131, a first bottom surface 132, and a first inner side surface 133 and a first outer side surface 134 respectively connecting the first top surface 131 and the first bottom surface 132, the inclined hole 12 is connected to one end of the first inner side surface 133 close to the first bottom surface 132, and the first air inlet hole 11 is connected to the first outer side surface 134.

[0039] Specifically, the first flange 10 is in a ring shape, an inclined hole 12 is formed between the first inner ring wall 14 and the first inner side surface 133 of the first flange 10, a first air inlet 11 is formed between the first outer ring wall 15 and the first outer side surface 134 of the first flange 10, and the first annular space 13 can be used to connect the first air inlet 11 and the inclined hole 12, so that the first annular space 13 has a certain buffer effect, avoiding the air intake direction of the first air inlet 11 affecting the guiding function of the inclined hole 12 for the inert gas. In addition, the inert gas in the first air inlet 11 can be evenly distributed to different inclined holes 12, ensuring that the inert gas entering the sub-chamber 40 through the inclined hole 12 can flow along a fixed loop.

[0040] In addition, in this embodiment, the number of the first air inlet holes 11 and the inclined holes 12 is not limited to meet different requirements. For example, the number of the inclined holes 12 can be eight, the number of the first air inlet holes 11 can be two, and the first annular space 13 can evenly distribute the inert gas passing through the two first air inlet holes 11 to the eight inclined holes 12. At this time, the number of the first air inlet ports 41 corresponds to the number of the inclined holes 12 to ensure uniform supply of the inert gas.

[0041] Embodiment 4

[0042] Reference Figure 1 On the basis of the above-mentioned third embodiment, the fourth embodiment of the present invention provides a single crystal furnace 100, wherein the first air inlet hole 11 is arranged along the horizontal direction.

[0043] In this embodiment, the first air inlet 11 can be arranged in the horizontal direction, so that the external inflation device can be arranged at a position far away from the main chamber 30 to avoid affecting the main chamber 30. At the same time, the air inlet direction of the first air inlet 11 is perpendicular to the direction of the first outer ring wall 15 of the first flange 10, which can facilitate the docking of the inflation device with the first air inlet 11 and shorten the distance to enter the first annular space 13 as much as possible.

[0044] Embodiment 5

[0045] Reference Figure 4 , Figure 5 and Figure 6 On the basis of the above-mentioned fourth embodiment, the fifth embodiment of the utility model provides a single crystal furnace 100, wherein the single crystal furnace 100 also includes a second flange 20, the second flange 20 is arranged on the main chamber 30, and the main chamber 30 is also provided with a second air inlet 31, the second flange 20 includes a second air inlet hole 21 and a third air inlet hole 22, the second air inlet hole 21 and the third air inlet hole 22 are coaxially arranged, the second air inlet hole 21 and the third air inlet hole 22 are connected, and the third air inlet hole 22 is connected to the second air inlet 31.

[0046] In this embodiment, the second flange 20 is reused, and the second flange 20 is provided with a second air inlet 21 and a third air inlet 22. The second air inlet 21 can be connected to an external gas charging device, and the third air inlet 22 is connected to the second air inlet 31. In this way, the inert gas can enter the main chamber 30 through the second air inlet 21, the third air inlet 22 and the second air inlet 31 in sequence, and blow in opposite directions. In this way, the airflow in the main chamber 30 can be prevented from carrying volatiles on the surface of the silicon melt back to the throat and agglomerating and then falling to cause pollution.

[0047] Embodiment 6

[0048] In addition, refer to Figure 1 and Figure 6 On the basis of the above-mentioned fifth embodiment, the sixth embodiment of the utility model provides a single crystal furnace 100, wherein a third air inlet 32 ​​is further provided on the main chamber 30, and the second flange 20 also includes a fourth air inlet hole 23, the axis of the fourth air inlet hole 23 intersects with the axis of the second air inlet hole 21, the second air inlet hole 21 is connected to the fourth air inlet hole 23, and the fourth air inlet hole 23 is connected to the third air inlet 32.

[0049] In this embodiment, the inert gas flows to the third and fourth gas inlets 22 and 23 respectively after passing through the second gas inlet 21, and then to the second gas inlet 31 and the third gas inlet 32 ​​respectively, so that the inert gas flow in the vertical direction can be provided while achieving horizontal blowing, thereby increasing the discharge speed of impurities volatilized from the surface of the silicon melt. In this way, after the first flange 10 is matched with the second flange 20, the purity of the single crystal round rod can be improved, so that the resistance accuracy and uniformity of the single crystal round rod are improved.

[0050] Embodiment 7

[0051] Reference Figure 6 On the basis of the sixth embodiment described above, the seventh embodiment of the present invention provides a single crystal furnace 100, wherein the second flange 20 further includes a second annular space 24, and the second annular space 24 is connected to the second air inlet 21, the third air inlet 22 and the fourth air inlet 23 respectively.

[0052] In addition, refer to Figure 1-Figure 4 The second annular space 24 includes a second top surface 241, a second bottom surface 242, and a second inner side surface 243 and a second outer side surface 244 respectively connecting the second top surface 241 and the second bottom surface 242. The second air inlet hole 21 is connected to the second outer side surface 244, the third air inlet hole 22 is connected to the second inner side surface 243, and the fourth air inlet hole 23 is connected to the second bottom surface 242.

[0053] Specifically, the second flange 20 is in a ring shape, a third air inlet 22 is formed between the second inner annular wall 25 and the second inner side surface 243 of the second flange 20, a second air inlet 21 is formed between the second outer annular wall 26 and the second outer side surface 244 of the second flange 20, and a fourth air inlet 23 is formed between the bottom wall 27 and the second bottom surface 242 of the second flange 20. The second annular space 24 can be used to connect the second air inlet 21, the third air inlet 22 and the fourth air inlet 23, so that the second annular space 24 has a certain buffering effect. In addition, the inert gas in the second air inlet 21 can be distributed to the third air inlet 22 and the fourth air inlet 23 in a certain amount, ensuring that the inert gas entering the main chamber 30 through the third air inlet 22 and the fourth air inlet 23 can flow along a fixed loop.

[0054] In addition, in this embodiment, the number of the second air inlet holes 21, the third air inlet holes 22 and the fourth air inlet holes 23 is not limited to meet different needs. For example, the number of the second air inlet holes 21 can be one, the number of the third air inlet holes 22 can also be one, and the number of the fourth air inlet holes 23 can be ten. The second annular space 24 can evenly distribute the inert gas passing through the two second air inlet holes 21 to the third air inlet holes 22 and the fourth air inlet holes 23. At this time, the number of the second air inlet holes 31 corresponds to the number of the third air inlet holes 22, and the number of the third air inlet holes 32 corresponds to the number of the fourth air inlet holes 23, so as to ensure the uniform supply of the inert gas.

[0055] Embodiment 8

[0056] Reference Figure 1 and Figure 6 On the basis of the sixth embodiment above, the eighth embodiment of the present invention provides a single crystal furnace 100, wherein the third air inlet 32 ​​is arranged along the vertical direction.

[0057] In this embodiment, the third air inlet 32 ​​can be arranged in the vertical direction in conjunction with the fourth air inlet 23, and the additional vertical downward inert gas path can more quickly remove various impurities volatilized from the surface of the silicon melt. In addition, in conjunction with the first flange 10, the probability of broken buds in each step of the Czochralski method can be reduced, the single crystal silicon pulling output can be increased, and the single crystal silicon production cost can be reduced.

[0058] In the single crystal furnace of the embodiment of the present application, the single crystal furnace includes a main chamber and a sub-chamber connected together and a first flange, the sub-chamber is arranged above the main chamber, the sub-chamber is provided with a first air inlet, the first flange is arranged on the sub-chamber, the first flange includes a first air inlet hole and an inclined hole arranged in sequence along the air inlet direction, the first air inlet hole and the inclined hole are connected, the inclined hole is connected to the first air inlet, wherein the inclined hole is arranged upwardly inclined along the gas inlet direction. In this way, the first flange can be reused, the inert gas can enter the sub-chamber through the first air inlet hole and the inclined hole of the first flange, the inclined hole can effectively reduce the eddy current in the sub-chamber, thereby reducing the impurities entering the main chamber area, and improving the single crystal silicon production efficiency.

[0059] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A single crystal furnace, characterized in that: include: A main chamber and a sub-chamber connected together, wherein the sub-chamber is arranged above the main chamber, and a first air inlet is provided on the sub-chamber; as well as A first flange is arranged on the sub-chamber, and the first flange includes a first air inlet hole and an inclined hole arranged in sequence along the air inlet direction, the first air inlet hole and the inclined hole are communicated, and the inclined hole is connected to the first air inlet port, wherein the inclined hole is arranged to be inclined upward along the gas inlet direction.

2. The single crystal furnace according to claim 1, characterized in that: The inclination angle of the inclined hole is 1° to 89°.

3. The single crystal furnace according to claim 1, characterized in that: The first flange further includes a first annular space, and the first annular space is respectively connected to the first air inlet hole and the inclined hole.

4. The single crystal furnace according to claim 3, characterized in that: The first annular space includes a first top surface, a first bottom surface, and a first inner side surface and a first outer side surface respectively connecting the first top surface and the first bottom surface, the inclined hole is connected to an end of the first inner side surface close to the first bottom surface, and the first air inlet hole is connected to the first outer side surface.

5. The single crystal furnace according to claim 3, characterized in that: The first air inlet holes are arranged along the horizontal direction.

6. The single crystal furnace according to claim 1, characterized in that: The single crystal furnace also includes a second flange, which is arranged on the main chamber. The main chamber is also provided with a second air inlet. The second flange includes a second air inlet hole and a third air inlet hole. The second air inlet hole and the third air inlet hole are coaxially arranged, the second air inlet hole and the third air inlet hole are connected, and the third air inlet hole is connected to the second air inlet hole.

7. The single crystal furnace according to claim 6, characterized in that: The main chamber is also provided with a third air inlet, and the second flange also includes a fourth air inlet hole, the axis of the fourth air inlet hole intersects with the axis of the second air inlet hole, the second air inlet hole is connected to the fourth air inlet hole, and the fourth air inlet hole is connected to the third air inlet.

8. The single crystal furnace according to claim 7, characterized in that: The second flange further includes a second annular space, and the second annular space is respectively connected to the second air inlet hole, the third air inlet hole, and the fourth air inlet hole.

9. The single crystal furnace according to claim 8, characterized in that: The second annular space includes a second top surface, a second bottom surface, and a second inner side surface and a second outer side surface respectively connecting the second top surface and the second bottom surface, the second air inlet hole is connected to the second outer side surface, the third air inlet hole is connected to the second inner side surface, and the fourth air inlet hole is connected to the second bottom surface.

10. The single crystal furnace according to claim 7, characterized in that: The third air inlet is arranged along the vertical direction.

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