Single crystal furnace

Abstract

The utility model relates to the technical field of single crystal silicon rod crystal pulling, in particular to a single crystal furnace, which comprises a furnace body and a furnace cover, a heater and a supporting bushing ring are arranged in the furnace body, the distance between the top of the heater and the supporting bushing ring is the distance between the furnace cover and the furnace body, a bottom thermal field is arranged on the inner bottom wall of the furnace body, and the furnace cover is arranged on the furnace body. And a liquid cooling lifting system is arranged at the bottom in the furnace body, is arranged around the bottom thermal field and is used for adjusting the device cover distance in the crystal pulling process. In the crystal pulling process, when the influence of the device cover distance on the crystal forming quality is realized, the liquid cooling lifting system can be used for adjusting the cover distance to improve the crystal forming quality.

Description

Technical Field

[0001] The utility model relates to the technical field of single crystal rod crystal pulling, and more specifically, to a single crystal furnace. Background Art

[0002] In specific industrial production scenarios, such as in the process of crystal growth or semiconductor material manufacturing, the installation of the thermal field is a crucial link. The traditional thermal field design usually adopts the following layout mode: from bottom to top, there are the bottom thermal field, the middle insulation layer, and the upper insulation layer in sequence. After the thermal field is installed, the distance between the cover and the thermal field (i.e., the distance between the cover and the thermal field, specifically the distance between the lower edge of the inner support lining ring in the furnace and the upper edge of the heater) is fixed within a specific range, usually between 25 and 45 millimeters. This setting directly affects the execution of subsequent processes and the quality of the finished product, but its limitations are gradually emerging.

[0003] Existing Problems:

[0004] 1. Influence of the distance between the cover and the thermal field on crystal formation:

[0005] - After the thermal field is installed, the distance between the cover and the thermal field cannot be dynamically adjusted. This means that during the crystal pulling process, even if it is realized that the distance between the cover and the thermal field affects the crystal formation quality (such as the crystal formation situation may deteriorate due to too small a distance between the cover and the thermal field), it is impossible to improve it by adjusting the distance between the cover and the thermal field. The current setting of the distance between the cover and the thermal field (about 25 millimeters) restricts the flexibility of process parameters to a certain extent, and may thus affect the quality of the final product.

[0006] - The setting of the distance between the cover and the thermal field also indirectly affects the oxygen content of the crystal rod. A smaller distance between the cover and the thermal field may result in a lower oxygen content in the crystal rod, which may be beneficial for certain applications (such as certain semiconductor materials), but may also be a limiting factor in other application scenarios.

[0007] 2. Cooling efficiency after furnace shutdown:

[0008] - When the thermal field is shut down, it is a common practice to cool it by flowing argon (usually an inert gas). However, this process takes about 10 hours, resulting in a significant loss of human efficiency in this stage of the entire system. The long cooling time not only prolongs the overall production cycle, increases energy consumption, but also may lead to uncertainty in production plans, affecting the continuity and efficiency of the production line. Summary of the Utility Model

[0009] The purpose of the utility model is to provide a single crystal furnace, which can solve at least one problem existing in the prior art.

[0010] The technical solution of the utility model is realized as follows:

[0011] A single crystal furnace includes a furnace body and a furnace cover. A heater and a support lining ring are arranged inside the furnace body. The distance between the top of the heater and the support lining ring is the distance from the heater to the cover. The inner bottom wall of the furnace body is provided with a bottom thermal field. A liquid-cooled lifting system is arranged at the inner bottom of the furnace body. The liquid-cooled lifting system is arranged around the bottom thermal field and is used to adjust the distance from the heater to the cover during the crystal pulling process.

[0012] Further, the liquid-cooled lifting system includes a lifting mechanism capable of lifting the furnace bottom during the furnace shutdown and cooling process.

[0013] Further, the lifting mechanism uses a lifting electrode.

[0014] Further, the liquid-cooled lifting system includes an annular liquid-cooled cavity. The liquid-cooled cavity is arranged outside the bottom thermal field. A liquid path structure is arranged inside the liquid-cooled cavity. The liquid path structure has a liquid inlet and a liquid outlet. The liquid inlet and the liquid outlet are respectively communicated with the two ports of a liquid supply mechanism to form a closed loop.

[0015] Further, a plurality of cooling holes are also opened on the liquid-cooled cavity. The heat flow of the bottom thermal field can be discharged from the cooling holes.

[0016] Further, the cooling holes are waist-shaped holes.

[0017] Further, the cooling holes are arranged in the upper part of the cavity, and a plurality of the cooling holes are evenly arranged around the bottom thermal field.

[0018] Further, a flow control unit is arranged on the liquid supply mechanism for controlling the liquid flow rate in the liquid path structure.

[0019] Further, the liquid supply mechanism uses a water pump, and the liquid conveyed in the water pump is water.

[0020] Further, the range of the distance from the heater to the cover is 25 mm to 45 mm.

[0021] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0022] In this application, a liquid-cooled lifting system is arranged at the inner bottom of the furnace body. The liquid-cooled lifting system is arranged around the bottom thermal field and can adjust the size of the distance from the heater to the cover during the crystal pulling process. During the crystal pulling process, when it is realized that the distance from the heater to the cover affects the crystal growth quality (such as the crystal growth situation may deteriorate due to too small a distance from the heater to the cover), the distance from the heater to the cover can be adjusted through the liquid-cooled lifting system to improve the crystal growth quality. Description of the Drawings

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0024] Figure 1 Isometric view of the single crystal furnace of the present invention;

[0025] Figure 2 Top view of the single crystal furnace of the present invention;

[0026] Figure 3 For the present invention Figure 2 Cross-sectional view taken along line A-A in the present invention;

[0027] Figure 4 Isometric view of the liquid cooling cavity of the present invention;

[0028] Figure 5 Front view of the liquid cooling cavity of the present invention.

[0029] In the figure:

[0030] 1 - furnace body; 2 - furnace cover; 3 - support lining ring; 4 - heater;

[0031] 5 - bottom thermal field; 6 - liquid cooling lifting system;

[0032] 7 - liquid cooling cavity; 701 - cooling hole; 702 - liquid inlet; 703 - liquid outlet. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0035] It should be noted that like reference numerals and letters refer to like items in the following figures; thus, once an item is defined in one figure, further definition and explanation thereof is not required in subsequent figures.

[0036] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of the present utility model is habitually placed during use. It 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 thus should not be construed as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0037] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0038] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may 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 according to specific circumstances.

[0039] The following will describe in detail some embodiments of the present utility model with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0040] Embodiment

[0041] In view of the problems existing in the prior art, the present application proposes a single crystal furnace (refer to Figures 1 - 5 ), which includes a furnace body 1 and a furnace cover 2. A heater 4 and a support lining ring 3 are arranged in the furnace body 1. The distance between the top of the heater 4 and the support lining ring 3 is the distance from the heater cover. The inner bottom wall of the furnace body 1 is provided with a bottom thermal field 5, and the bottom thermal field 5 includes a support cylinder, a bottom solid felt, and a guard plate pressing piece located at the top. A liquid cooling lifting system 6 is arranged at the inner bottom of the furnace body 1, and the liquid cooling lifting system 6 is arranged around the bottom thermal field 5 (as Figure 3) is used to adjust the device cover distance during the crystal pulling process.

[0042] Specifically, the liquid cooling lifting system 6 includes a lifting mechanism that can lift the furnace bottom during the furnace shutdown and temperature reduction process.

[0043] The lifting mechanism adopts a lifting electrode, and the lifting electrode adjuster cover distance is used at the bottom of the single crystal furnace. The lifting electrode is introduced as follows:

[0044] A lift electrode is a device used in certain industrial applications, mainly for electric heating or arc heating applications in crystal growth, molten metal processing, and other high temperature environments. It usually consists of one or more electrodes that can move in a vertical direction (usually up and down). The lift electrode is designed to change the distance between the electrode and the molten material or solid surface when necessary, thereby adjusting the electric heating power, improving the heating or melting process of the material, or adjusting other process parameters. For example, during the crystal growth process, the lift electrode can be used to adjust the cover distance (i.e., the distance between the cover of the crystal growth chamber and the bottom thermal field 5). By changing the position of the electrode, the distance between the heat source and the cover of the growth chamber can be adjusted, which in turn affects the heating efficiency and the quality of crystal growth. In some cases, the lift electrode can also help adjust the temperature distribution of the heating zone, which is very important for obtaining uniform and consistent crystal growth. The use of lift electrodes can bring many advantages, including increased process flexibility, optimized crystal growth conditions, reduced energy consumption, and improved production efficiency and product quality.

[0045] The liquid cooling lifting system 6 includes an annular liquid cooling cavity 7, which is arranged outside the bottom thermal field 5. A liquid path structure is arranged inside the liquid cooling cavity 7, and the liquid path structure has a liquid inlet 702 and a liquid outlet 703 (such as Figure 5 ), the liquid inlet 702 and the liquid outlet 703 are respectively connected to the two ports of the liquid supply mechanism to form a closed loop, and the cooling liquid is circulated into the liquid path structure through the liquid supply mechanism, and the liquid takes away heat during the flow.

[0046] The liquid supply mechanism may be a water pump, and the liquid transported by the water pump is water. The input port of the water pump is connected to the liquid outlet 703 of the liquid path structure, and the output port of the water pump is connected to the liquid inlet 702 of the liquid path structure through a pipeline.

[0047] The liquid supply mechanism is provided with a flow control unit for controlling the liquid flow in the liquid path structure.

[0048] Specifically, a flow control unit is provided between the water pump and the liquid inlet 702 , and the flow control unit may adopt a flow valve to control the flow size.

[0049] A plurality of cooling holes 701 (such as Figure 4 ), the heat flow of the bottom thermal field 5 can be discharged from the cooling hole 701, and the cooling hole 701 is arranged at the upper part of the cavity, and a plurality of the cooling holes 701 are evenly arranged around the bottom thermal field 5.

[0050] Preferably, the cooling hole is designed as a waist-shaped hole.

[0051] The range of the device cover distance is generally 25 mm to 45 mm, and the specific device cover distance is adjusted according to demand. When the crystal pulling condition is poor during the crystal pulling process or the crystal rod oxygen content of the crystal pulling output is high and cannot meet the demand, the liquid cooling lifting system 6 can be used for lifting and lowering adjustment.

[0052] When the furnace is shut down, the liquid cooling lifting system 6 starts to work, lifting the bottom of the furnace so that the airflow in the bottom heat field 5 flows out from the multiple cooling holes 701 in the liquid cooling lifting system 6, continuously reducing the temperature of the airflow in the furnace and improving the cooling effect. A liquid path structure is provided inside the liquid cooling lifting system 6. When the furnace is shut down and cooled, the flow valve is controlled to control the water flow, and the water flow will be opened to the maximum value at this time to increase the water flow speed and minimize the temperature in the furnace; when the crystal pulling state is normal, the water flow is controlled to be opened to the minimum safe water flow so that the water cooling system does not take away more heat.

[0053] This new water cooling system includes the following key parts:

[0054] 1. Liquid-cooled lifting system 6: This system can adjust the device cover distance, so that the device cover distance can be adjusted as needed during the crystal pulling process.

[0055] 2. Water cooling: When the furnace is shut down, the liquid cooling lifting system can accelerate the cooling by lifting the bottom of the furnace so that the air flow in the bottom hot field flows out from the cooling holes.

[0056] 3. Internal liquid circuit structure: The liquid cooling lifting system 6 is provided with a liquid circuit structure, which can control the cooling speed by adjusting the water flow. During normal crystal pulling, the water flow is small; when the furnace is stopped for cooling, the water flow will increase to quickly reduce the temperature in the furnace.

[0057] Compared with the existing technology, this application has the following significant advantages:

[0058] 1. Adjustable device cover distance: The device cover distance can be adjusted at any time as needed during the crystal pulling process.

[0059] 2. Adjust the bottom temperature: control the bottom temperature by adjusting the water flow rate.

[0060] 3. Shorten the shutdown time: The water cooling system greatly shortens the cooling time after shutdown.

[0061] Key Points:

[0062] The key points of this technical solution are as follows:

[0063] 1. Bottom lifting electrode: The distance between the regulator cover is adjusted by the bottom lifting electrode.

[0064] 2. Water cooling system design: A set of efficient water cooling systems are designed, including cooling holes and internal water channel structures (i.e., liquid channel structures).

[0065] The beneficial effects of the technical solution of this utility model are as follows:

[0066] 1. The distance between the regulator cover can be adjusted, and during the crystal pulling process (by lifting to adjust the distance between the regulator cover);

[0067] 2. The temperature at the bottom of the single crystal furnace can be adjusted (by adjusting the water flow rate);

[0068] 3. The furnace shutdown time can be reduced (by reducing the temperature through the bottom water cooling system).

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model.

[0070] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A single crystal furnace, comprising a furnace body (1) and a furnace lid (2), wherein a heater (4) and a support lining ring (3) are arranged inside the furnace body (1), the distance between the top of the heater (4) and the support lining ring (3) is the distance from the heater to the lid, and a bottom thermal field (5) is arranged on the inner bottom wall of the furnace body (1), and is characterized in that, A liquid-cooled lifting system (6) is provided at the inner bottom of the furnace body (1). The liquid-cooled lifting system (6) is arranged around the bottom heat field (5) and is used to adjust the distance between the cover and the crucible during the crystal pulling process.

2. The single crystal furnace according to claim 1, wherein The liquid-cooled lifting system (6) includes a lifting mechanism that can lift the furnace bottom during the furnace shutdown and cooling process.

3. The single crystal furnace according to claim 2, characterized in that, The lifting mechanism uses a lifting electrode.

4. The single crystal furnace according to claim 1, characterized in that, The liquid-cooled lifting system (6) includes an annular liquid-cooled cavity (7). The liquid-cooled cavity (7) is arranged outside the bottom heat field (5). A liquid path structure is arranged inside the liquid-cooled cavity (7). The liquid path structure has a liquid inlet (702) and a liquid outlet (703). The liquid inlet (702) and the liquid outlet (703) are respectively communicated with both ends of a liquid supply mechanism to form a closed loop.

5. The single crystal furnace according to claim 4, characterized in that, A plurality of cooling holes (701) are also opened on the liquid-cooled cavity (7). The heat flow of the bottom heat field (5) can be discharged from the cooling holes (701).

6. The single crystal furnace according to claim 5, characterized in that, The cooling holes (701) are arranged at the upper part of the cavity, and a plurality of the cooling holes (701) are evenly arranged around the bottom heat field (5).

7. The single crystal furnace according to claim 6, characterized in that, The cooling holes (701) are waist-shaped holes.

8. The single crystal furnace according to claim 4, wherein A flow control unit is arranged on the liquid supply mechanism to control the liquid flow rate in the liquid path structure.

9. The single crystal furnace according to claim 4, characterized in that, The liquid supply mechanism uses a water pump, and the liquid conveyed in the water pump is water.

10. The single crystal furnace according to claim 1, characterized in that, The range of the distance between the cover and the crucible is 25 mm to 45 mm.

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