Cooling device for increasing pulling speed of monocrystalline silicon and single crystal furnace

Abstract

The utility model provides a cooling device and a single crystal furnace for improving the pulling speed of monocrystalline silicon, the cooling device comprises a water-cooled jacket, the water-cooled jacket is provided with a water inlet pipe and a water outlet pipe which correspond to each other, and a first air inlet pipe and a second air inlet pipe are respectively arranged in the water inlet pipe and the water outlet pipe in a penetrating manner; the first air inlet pipe and the second air inlet pipe extend into the water cooling sleeve and communicate with the outside through a first air outlet hole and a second air outlet hole which are located in the inner side wall of the water cooling sleeve and are different in height. Cold water is supplied through the water inlet pipe, and the cold water exchanges heat with the crystal pulling side to meet the requirements of different crystal pulling stages on temperature; cold air is supplied through the first air inlet pipe and the second air inlet pipe, the temperature of water close to the inner side wall of the water-cooled jacket is reduced in an accelerated mode, the cooling effect of water in the water-cooled jacket is improved, meanwhile, the cold air is directly blown to the crystal pulling side through the first air outlet hole and the second air outlet hole, hot air close to single crystals is efficiently discharged, the axial temperature gradient of the crystal pulling side is adjusted, and the pulling speed of the single crystal silicon is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of single crystal silicon production, in particular to a cooling device and a single crystal furnace for improving the pulling speed of single crystal silicon. Background Technique

[0002] Single crystal silicon is the electronic information basic material for semiconductor devices such as contemporary artificial intelligence, automatic control, information processing, and optoelectronic conversion. At the same time, it also has a huge market in the photovoltaic industry. The conversion efficiency of single crystal silicon cells is 5% higher than that of traditional polycrystalline silicon cells, but the production cost of single crystal silicon is relatively high. At present, on the premise of ensuring crystal quality, improving production efficiency has become a breakthrough point for reducing production costs.

[0003] The direct method to improve production efficiency is to increase the crystal pulling speed and shorten the crystal growth cycle. As the crystal pulling speed increases, the latent heat of crystallization released during the crystallization process of the crystal increases linearly. Therefore, the heat dissipation capacity on the crystal side must be strengthened. At the same time, during the crystal pulling process, the V / G ratio on the crystal side of the solidification interface is an important indicator for measuring crystal quality, where V is the crystal growth speed and G is the axial temperature gradient on the crystal side at the solidification interface. Too high or too low V / G ratio will cause a large number of defects to form inside the crystal during the crystal pulling process. Therefore, while increasing the crystal pulling speed, the axial temperature gradient on the crystal side at the solidification interface must also be increased accordingly.

[0004] At present, the cooling methods for the Czochralski single crystal process include air cooling and water cooling. Air cooling means continuously introducing a cooling gas (generally argon) into the single crystal furnace and continuously exhausting the hot gas. The residence time of the cooling gas in the furnace is short, and the heat finally taken away is 80% - 85% of the total heat. The cooling effect is average and the consumption cost of the cooling gas is high; while water cooling is to add a cold water jacket between the inner wall and the outer wall of the guide cylinder. The main heat exchange part of the cold water jacket is the wall surface close to the single crystal. Its contact area with the heat in the furnace is small, the heat quickly absorbed is less, and the heat exchange efficiency is not high, so it cannot effectively increase the single crystal pulling speed. Content of the Utility Model

[0005] The purpose of the utility model is to provide a cooling device and a single crystal furnace for improving the pulling speed of single crystal silicon, so as to solve the problems in the above background.

[0006] The technical solution adopted by the utility model is: a cooling device for improving the pulling speed of single crystal silicon, which includes a water cooling jacket. A corresponding water inlet pipe and a water outlet pipe are provided on the water cooling jacket, and a first air inlet pipe and a second air inlet pipe are respectively penetrated in the water inlet pipe and the water outlet pipe; the first air inlet pipe and the second air inlet pipe respectively extend into the interior of the water cooling jacket and are respectively communicated with the outside through a first air outlet hole and a second air outlet hole at different heights on the inner side wall of the water cooling jacket.

[0007] Preferably, along the height direction of the water-cooling jacket, the first air outlet holes are located at the bottom end of the water-cooling jacket and are distributed circumferentially around the water-cooling jacket, and each of the first air outlet holes is connected to the first air inlet pipe through a first shunt pipe.

[0008] Preferably, along the height direction of the water-cooling jacket, the second air outlet holes are located in the middle of the water-cooling jacket and are distributed circumferentially around the water-cooling jacket, and each of the second air outlet holes is connected to the second air inlet pipe through a second shunt pipe.

[0009] Preferably, with the inner side wall of the water-cooling jacket as the base surface, the included angle between the side wall of the first air outlet hole and the base surface is between 0° and 180°, and the included angle between the side wall of the second air outlet hole and the base surface is between 0° and 180°.

[0010] Preferably, the first air outlet hole includes one or a combination of more of the first air outlet hole A, the first air outlet hole B, and the first air outlet hole C. The top end of the side wall of the first air outlet hole A deviates from the first air inlet pipe, the side wall of the first air outlet hole B extends horizontally, and the top end of the side wall of the first air outlet hole C faces the first air inlet pipe.

[0011] Preferably, the second air outlet hole includes one or a combination of more of the second air outlet hole A, the second air outlet hole B, and the second air outlet hole C. The top end of the side wall of the second air outlet hole A deviates from the second air inlet pipe, the side wall of the second air outlet hole B extends horizontally, and the top end of the side wall of the second air outlet hole C faces the second air inlet pipe.

[0012] Preferably, elbow joints are respectively provided at the top ends of the water inlet pipe and the water outlet pipe, and the first air inlet pipe and the second air inlet pipe respectively penetrate through different elbow joints and are connected to different air supply valves located outside the water-cooling jacket.

[0013] The technical solution adopted by the present invention further includes: a single crystal furnace, and the internal structure of the single crystal furnace is provided with a cooling device for improving the pulling speed of single crystal silicon as described above.

[0014] The beneficial effects of the present invention are as follows: (1) Cold water is supplied to the water-cooling jacket through the water inlet pipe, and the cold water exchanges heat with the crystal pulling side through the inner side wall of the water-cooling jacket, and the water speed is controlled to adapt to the temperature requirements in different crystal pulling stages; in the isodiameter crystal pulling stage, cold air can be supplied through the first air inlet pipe and the second air inlet pipe to accelerate the reduction of the water temperature near the inner side wall of the water-cooling jacket, improve the cooling effect of the water in the water-cooling jacket, and at the same time directly blow the cold air to the crystal pulling side through the first air outlet holes and the second air outlet holes, efficiently discharge the hot air near the single crystal, reduce the temperature near the single crystal, adjust the axial temperature gradient of the crystal pulling side, and improve the pulling speed of single crystal silicon;

[0015] (2) The first intake pipe and the second intake pipe are independent of each other and are controlled separately. The first air outlet and the second air outlet are independent of each other and have different heights. By adjusting the on / off or opening degree of the first intake pipe and the second intake pipe, the temperature at different heights on the crystal pulling side can be accurately adjusted, improving the accuracy of the axial temperature gradient. While increasing the pulling speed of monocrystalline silicon, the crystal pulling quality of monocrystalline silicon is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the front view cross-sectional view of the embodiment of the present utility model;

[0017] Figure 2 is the top view of the first intake pipe and the first shunt pipe in the embodiment of the present utility model;

[0018] Figure 3 is the structural schematic diagram of the first air outlet in the embodiment of the present utility model.

[0019] In the figure:

[0020] 1, water-cooling jacket; 2, water inlet pipe; 3, water outlet pipe; 4, first intake pipe; 5, second intake pipe; 6, first air outlet; 7, second air outlet; 8, elbow joint; 9, gas supply valve; 10, first shunt pipe; 11, second shunt pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The technical solutions of the embodiments of the present utility model will be described in detail below with reference to the drawings.

[0022] In the description of the embodiments of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "set", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific situations.

[0023] Refer to the attached Figures 1-3The embodiment of the utility model provides a cooling device for improving the pulling speed of single crystal silicon, which includes a water-cooling jacket 1, a water inlet pipe 2, a water outlet pipe 3, a first air inlet pipe 4 and a second air inlet pipe 5. The water inlet pipe 2 and the water outlet pipe 3 are respectively arranged at the top of the water-cooling jacket 1, and are respectively used to supply water and drain water to the water-cooling jacket 1; the first air inlet pipe 4 is penetrated in the water inlet pipe 2, one end of which extends to the inside of the water-cooling jacket 1 and communicates with the outside through a first air outlet hole 6 located on the inner side wall of the water-cooling jacket 1; the second air inlet pipe 5 is penetrated in the water outlet pipe 3, one end of which extends to the inside of the water-cooling jacket 1 and communicates with the outside through a second air outlet hole 7 located on the inner side wall of the water-cooling jacket 1, wherein the heights of the first air outlet hole 6 and the second air outlet hole 7 are different.

[0024] The water-cooling jacket 1 in this embodiment has a conventional cylindrical outer contour and an inner cavity, which serves as a water channel. It should be noted that the outer wall of the water-cooling jacket 1 mentioned above refers to the wall on the side of the water-cooling jacket 1 that is away from the single crystal in actual operation; the inner wall of the water-cooling jacket 1 refers to the wall on the side of the water-cooling jacket 1 that is close to the single crystal in actual operation, rather than the inner wall in the traditional sense, which is the wall surface in contact with cold water.

[0025] When the above-mentioned cooling device is used for production, cold water is first supplied to the water-cooling jacket 1 through the water inlet pipe 2. The cold water exchanges heat with the crystal pulling side through the inner wall of the water-cooling jacket 1, and the temperature requirements of different crystal pulling stages are adapted to by controlling the water speed. In the equal-diameter crystal pulling stage, cold air (which may be an inert gas such as argon) can be supplied through the first air inlet pipe 4 and the second air inlet pipe 5. On the one hand, the cold air can exchange heat with the water in the water-cooling jacket 1 through the side walls of the first air inlet pipe 4 and the second air inlet pipe 5, thereby accelerating the reduction of the water temperature near the inner wall of the water-cooling jacket 1 and improving the cooling effect of the water in the water-cooling jacket 1. On the other hand, the cold air can be directly blown toward the crystal pulling side through the first air outlet 6 and the second air outlet 7, thereby efficiently discharging the hot air near the single crystal, reducing the temperature near the single crystal, adjusting the axial temperature gradient on the crystal pulling side, and increasing the single crystal silicon pulling speed.

[0026] During implementation, elbow joints 8 can be respectively constructed at the top of the water inlet pipe 2 and the water outlet pipe 3, and the first air inlet pipe 4 and the second air inlet pipe 5 are respectively passed through different elbow joints 8, connected to different air supply valves 9 located outside the water cooling jacket 1, and the elbow joints 8 are connected to the water source (on the side of the water inlet pipe 2) or the drainage area (on the side of the water outlet pipe 3). It is worth noting that the side wall of the first air inlet pipe 4 and the side wall of the elbow joint 8, and the side wall of the second air inlet pipe 5 and the side wall of the elbow joint 8 need to be sealed and connected (for example, welded) to prevent water leakage.

[0027] The first air inlet pipe 4 and the second air inlet pipe 5 are independent of each other and are controlled separately, the first air outlet 6 and the second air outlet 7 are independent of each other and have different heights. By adjusting the on-off or opening degree of the first air inlet pipe 4 and the second air inlet pipe 5, the temperature at different heights on the crystal pulling side can be accurately adjusted to improve the accuracy of the axial temperature gradient, thereby increasing the pulling speed of the single crystal silicon and ensuring the crystal pulling quality of the single crystal silicon.

[0028] During specific implementation, along the height direction of the water cooling jacket 1: the first air outlet 6 is arranged at the bottom end of the water cooling jacket 1, and a plurality of the first air outlets 6 are distributed around the circumference of the water cooling jacket 1, and each first air outlet 6 is connected to the first air inlet pipe 4 via a first shunt pipe 10; the second air outlet 7 is arranged in the middle part of the water cooling jacket 1, and a plurality of the second air outlets 7 are distributed around the circumference of the water cooling jacket 1, and each second air outlet 7 is connected to the second air inlet pipe 5 via a second shunt pipe 11. Among them: the bottom end of the first air inlet pipe 4 is bent into a circular ring shape, and a hole structure connected to the first diverter pipe 10 is provided on its side wall. The number of the first diverter pipes 10 and the first air outlet holes 6 are the same and the positions correspond. The end of the first diverter pipe 10 away from the first air outlet hole 6 is fixedly connected (for example, welded) to the first air inlet pipe 4. The bottom end of the second air inlet pipe 5 is also bent into a circular ring shape, and a hole structure connected to the second diverter pipe 11 is provided on its side wall. The number of the second diverter pipes 11 and the second air outlet holes 7 are the same and the positions correspond. The end of the second diverter pipe 11 away from the second air outlet hole 7 is fixedly connected (for example, welded) to the second air inlet pipe 5.

[0029] According to different usage requirements, the orientation of the first air outlet 6 and the second air outlet 7 can be personalized, so that the cold air flows in the specified direction after passing through the first air outlet 6 and the second air outlet 7, and then flows downward by gravity and molecular diffusion to change its efficiency of discharging hot air. Specifically: taking the inner side wall of the water-cooling jacket 1 as the base surface, the angle between the side wall of the first air outlet 6 and the base surface is between 0° and 180, and the angle between the side wall of the second air outlet 7 and the base surface is between 0° and 180, that is, the orientation of the first air outlet 6 can be upward, horizontal or downward, and the orientation of the second air outlet 7 can also be upward, horizontal or downward. The specific inclination angle can be configured according to actual needs and is not specifically limited here.

[0030] When implementing it specifically (see Appendix Figure 3) The first air outlet 6 may include one or a combination of more than one of the first air outlet A, the first air outlet B, and the first air outlet C, where: the top end of the side wall of the first air outlet A faces away from the first air inlet pipe 4, the side wall of the first air outlet B extends horizontally, and the top end of the side wall of the first air outlet C faces the first air inlet pipe 4. That is: the multiple first air outlets 6 circumferentially distributed along the water-cooling jacket 1 can all be horizontal, all be upward, all be downward, or can be alternately distributed with two types of upward and horizontal, alternately distributed with two types of downward and horizontal, alternately distributed with two types of upward and downward, or can also be alternately distributed with three types of upward, downward, and horizontal.

[0031] Similarly, the second air outlet 7 may also include one or a combination of more than one of the second air outlet 7A, the second air outlet 7B, and the second air outlet 7C. The top end of the side wall of the second air outlet 7A faces away from the second air inlet pipe 5, the side wall of the second air outlet 7B extends horizontally, and the top end of the side wall of the second air outlet 7C faces the second air inlet pipe 5. That is: the multiple second air outlets 7 circumferentially distributed along the water-cooling jacket 1 can all be horizontal, all be upward, all be downward, or can be alternately distributed with two types of upward and horizontal, alternately distributed with two types of downward and horizontal, alternately distributed with two types of upward and downward, or can also be alternately distributed with three types of upward, downward, and horizontal.

[0032] The embodiment of the present utility model also provides a single crystal furnace, the internal structure of which is provided with a cooling device for improving the pulling speed of single crystal silicon as described above.

[0033] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0034] (1) Cold water is supplied to the water-cooling jacket 1 through the water inlet pipe 2. The cold water exchanges heat with the crystal pulling side through the inner side wall of the water-cooling jacket 1, and the water speed is controlled to meet the temperature requirements of different crystal pulling stages; during the isodiameter crystal pulling stage, cold air can be supplied through the first air inlet pipe 4 and the second air inlet pipe 5 to accelerate the reduction of the water temperature near the inner side wall of the water-cooling jacket 1, improve the cooling effect of the water in the water-cooling jacket 1, and at the same time directly blow the cold air to the crystal pulling side through the first air outlet 6 and the second air outlet 7, efficiently discharge the hot air near the single crystal, reduce the temperature near the single crystal, adjust the axial temperature gradient of the crystal pulling side, and improve the pulling speed of single crystal silicon;

[0035] (2) The first air inlet pipe 4 and the second air inlet pipe 5 are independent of each other and are respectively controlled. The first air outlet 6 and the second air outlet 7 are independent of each other and have different heights. By adjusting the on-off or opening degree of the first air inlet pipe 4 and the second air inlet pipe 5, the temperature at different heights of the crystal pulling side can be accurately adjusted, the accuracy of the axial temperature gradient can be improved, and while improving the pulling speed of single crystal silicon, the crystal pulling quality of single crystal silicon is ensured.

[0036] The above are the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as within the protection scope of the present utility model.

Claims

1. A cooling device for increasing the pulling speed of single crystal silicon, characterized in that, It includes a water-cooling jacket, and corresponding water inlet pipe and water outlet pipe are provided on the water-cooling jacket, and a first air inlet pipe and a second air inlet pipe are respectively penetrated in the water inlet pipe and the water outlet pipe; the first air inlet pipe and the second air inlet pipe respectively extend into the interior of the water-cooling jacket and are respectively communicated with the outside through a first air outlet hole and a second air outlet hole at different heights on the inner side wall of the water-cooling jacket.

2. The cooling device for increasing the pulling rate of single crystal silicon according to claim 1, wherein Along the height direction of the water-cooling jacket, the first air outlet hole is located at the bottom end of the water-cooling jacket, and a plurality of the first air outlet holes are circumferentially distributed around the water-cooling jacket, and each of the first air outlet holes is respectively connected to the first air inlet pipe through a first shunt pipe.

3. The cooling device for increasing the pulling speed of single crystal silicon according to claim 1 or 2, characterized in that, Along the height direction of the water-cooling jacket, the second air outlet hole is located in the middle of the water-cooling jacket, and a plurality of the second air outlet holes are circumferentially distributed around the water-cooling jacket, and each of the second air outlet holes is respectively connected to the second air inlet pipe through a second shunt pipe.

4. The cooling device for increasing the pulling rate of single crystal silicon according to claim 3, characterized in that, Taking the inner side wall of the water-cooling jacket as a base surface, the included angle between the side wall of the first air outlet hole and the base surface is between 0° and 180°, and the included angle between the side wall of the second air outlet hole and the base surface is between 0° and 180°.

5. The cooling device for increasing the pulling rate of single crystal silicon according to claim 4, characterized in that, The first air outlet hole includes one or a combination of more of the first air outlet hole A, the first air outlet hole B, and the first air outlet hole C. The top end of the side wall of the first air outlet hole A deviates from the first air inlet pipe, the side wall of the first air outlet hole B extends horizontally, and the top end of the side wall of the first air outlet hole C faces the first air inlet pipe.

6. The cooling device for increasing the pulling rate of single crystal silicon according to claim 4, characterized in that, The second air outlet hole includes one or a combination of more of the second air outlet hole A, the second air outlet hole B, and the second air outlet hole C. The top end of the side wall of the second air outlet hole A deviates from the second air inlet pipe, the side wall of the second air outlet hole B extends horizontally, and the top end of the side wall of the second air outlet hole C faces the second air inlet pipe.

7. The cooling device for increasing the pulling speed of single crystal silicon according to any one of claims 1-2, 4-6, characterized in that Elbow joints are respectively provided at the top ends of the water inlet pipe and the water outlet pipe, and the first air inlet pipe and the second air inlet pipe respectively penetrate through different elbow joints and are connected to different air supply valves located outside the water-cooling jacket.

8. A single crystal furnace, characterized in that, The interior of the single crystal furnace is configured with the cooling device for improving the pulling rate of single crystal silicon according to any one of claims 1-7.

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