Energy-saving inner guide cylinder of guide cylinder assembly of monocrystalline silicon furnace, guide cylinder assembly for monocrystalline silicon furnace and monocrystalline silicon furnace

Abstract

The utility model relates to the field of monocrystalline silicon production equipment, in particular to an energy-saving inner guide cylinder, a guide cylinder assembly and a monocrystalline silicon furnace. The utility model provides an energy-saving inner guide cylinder of a guide cylinder assembly of a monocrystalline silicon furnace, the inner side surface of the inner guide cylinder is inclined upwards, the outer side surface of the inner guide cylinder is inclined downwards, and a heat radiation reflecting layer is covered on the outer side surface. The utility model further provides a guide cylinder assembly for the monocrystalline silicon furnace, the guide cylinder assembly comprises an outer guide cylinder arranged on the outer side and an inner guide cylinder arranged on the inner side, the outer guide cylinder and the inner guide cylinder are installed together, the inner guide cylinder is as described above, and the heat radiation reflecting layer of the inner guide cylinder faces the outer guide cylinder. The utility model also provides a monocrystalline silicon furnace, the upper part in the furnace body is provided with a seed crystal for crystal pulling, the lower part in the furnace body is provided with a heating element, a guide cylinder assembly is arranged between the seed crystal and the heating element, the guide cylinder assembly surrounds the outer side of the seed crystal, and the guide cylinder assembly is as mentioned above. The inner guide cylinder not only saves energy, but also is not easy to cause adverse effects on cooling forming of the silicon single crystal rod.

Description

Technical Field

[0001] The utility model relates to the field of single crystal silicon production equipment, in particular to an energy-saving inner guide tube of a single crystal silicon furnace guide tube assembly, a guide tube assembly with the inner guide tube, and a single crystal silicon furnace with the guide tube assembly. Background Art

[0002] Single crystal silicon is the substrate material for most semiconductor components. Currently, most single crystal silicon is produced using the Czochralski method (also known as the J. Czochralski method) in a single crystal silicon furnace (also known as a reduction furnace). Chinese patent document CN110904496A discloses a single crystal silicon furnace comprising a furnace body, within which a flow guide tube 2 is provided, dividing the interior of the furnace into an upper and lower portion. The lower portion of the furnace body houses a quartz crucible 18 for holding raw materials such as polycrystalline silicon chunks. Quartz crucible 18 is mounted within a graphite crucible 15, and a heater 14 is located outside of quartz crucible 18. The upper portion of the furnace body houses a seed crystal and a lifting mechanism for moving the seed crystal up and down. When pulling a single crystal silicon rod, heater 14 heats the raw material in quartz crucible 18 until it melts. After the molten raw material liquid is adjusted to the process temperature, the seed crystal is passed from top to bottom through the guide tube and inserted into the molten raw material liquid. It is then lifted upward while rotating counterclockwise relative to quartz crucible 18, causing the raw material liquid to crystallize and solidify into a single crystal silicon rod in the order of the silicon atoms in the seed crystal. As the seed crystal slowly rises, it pulls the single crystal silicon rod solidified on it upward through the guide tube 2. When the single crystal silicon rod of the appropriate length is pulled, the seed crystal stops rotating, and the raw material liquid no longer precipitates silicon crystals. The pulled single crystal silicon rod cools to produce the desired single crystal silicon rod.

[0003] There are three basic ways of heat transfer: heat conduction, heat radiation and heat convection. As long as there is a temperature difference inside an object or between objects, heat energy will inevitably be transferred from high temperature to low temperature in one or more of these three ways. In a single crystal silicon furnace, since the guide tube is not in direct contact with the single crystal silicon rods to be cooled in the upper part of the furnace body, nor is it in direct contact with the heater in the lower part of the furnace body, heat is mainly transferred between them through heat radiation. As mentioned above, the guide tube divides the interior of the furnace body into two parts, so that the heat generated by the heater in the lower part of the furnace body cannot be directly transferred to the upper part of the furnace body, thereby avoiding affecting the cooling and forming of the single crystal silicon rods. The existing guide tube is funnel-shaped, usually composed of an outer guide tube and an inner guide tube, wherein the outer guide tube is close to the heater in the lower part of the furnace body, and the inner guide tube is close to the single crystal silicon rods to be cooled in the upper part of the furnace body. During operation, this guide tube will, on the one hand, receive heat radiation from the lower part of the furnace body, wasting the heat energy of the lower part of the furnace body; on the other hand, it will heat up after receiving the heat radiation, and after heating up, it will emit heat radiation outward, which will have an adverse effect on the cooling and forming of the single crystal silicon rod to be cooled in the upper part of the furnace body. Utility Model Content

[0004] The technical problem to be solved by the present invention is to provide an inner guide tube of a guide tube assembly of a single crystal silicon furnace, a guide tube assembly having the inner guide tube, and a single crystal silicon furnace having the guide tube assembly, wherein the inner guide tube is energy-saving and not likely to cause adverse effects on the cooling and forming of single crystal silicon rods.

[0005] To solve the above problems, the utility model provides an energy-saving inner guide tube of a single crystal silicon furnace guide tube assembly, wherein the inner side surface of the inner guide tube is inclined upward and the outer side surface is inclined downward, and the outer side surface is covered with a heat radiation reflecting layer.

[0006] Furthermore, an adhesive layer is provided between the outer side surface and the heat radiation reflecting layer, and the heat radiation reflecting layer is adhered to the outer side surface through the adhesive layer.

[0007] Furthermore, the heat radiation reflecting layer is a silver layer.

[0008] Furthermore, the thermal radiation reflecting layer has a thickness of 3 to 50 μm.

[0009] A guide tube assembly for a single crystal silicon furnace is also provided, comprising an outer guide tube arranged on the outside and an inner guide tube arranged on the inside. The outer guide tube and the inner guide tube are installed together. The inner guide tube is as described above, and the heat radiation reflection layer of the inner guide tube faces the outer guide tube.

[0010] Furthermore, the outer guide tube and the inner guide tube together form a heat-insulating cavity, and the heat radiation reflecting layer of the inner guide tube is accommodated in the heat-insulating cavity.

[0011] Furthermore, the heat-insulating cavity is vacuum or filled with heat-insulating material.

[0012] A single crystal silicon furnace is also provided, wherein a seed crystal for crystal pulling is installed at the upper part of the furnace body and a heating element is installed at the lower part of the furnace body. A guide tube assembly is provided between the seed crystal and the heating element, which surrounds the outside of the seed crystal. The guide tube assembly is as described above.

[0013] Beneficial effect: After the inner guide tube is installed in the single crystal silicon furnace, its downward inclined outer side surface faces the lower part of the single crystal silicon furnace body. In this way, the heat radiation from the lower part of the single crystal silicon furnace body is reflected by the heat radiation reflecting layer on the outer side surface of the inner guide tube in the process of being emitted to the upper part of the furnace body and then returns to the lower part of the furnace body. The inner guide tube thereby reduces the amount of heat radiation received from the lower part of the furnace body, thereby reducing the loss of heat energy in the lower part of the furnace body and achieving energy-saving effect. Since the inner guide tube reduces the amount of heat radiation received from the lower part of the furnace body, it is not easy for itself to heat up, and it is not easy to emit heat radiation outward, which is not easy to cause adverse effects on the cooling and forming of the single crystal silicon rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of a single crystal silicon furnace.

[0015] Figure 2 It is a schematic diagram of the structure of the guide tube assembly.

[0016] Figure 3 yes Figure 2 Enlarged view of part A.

[0017] Explanation of symbols:

[0018] 1-Single crystal silicon furnace; 11-Upper part of the furnace body; 12-Lower part of the furnace body; 13-Seed crystal; 14-Lifting mechanism; 15-Crucible; 16-Heating element; 2-Guide tube assembly; 21-Outer guide tube; 22-Inner guide tube; 221-Inner side surface; 222-Outer side surface; 223-Adhesive layer; 224-Heat radiation reflecting layer; 23-Insulation cavity; 3-Single crystal silicon rod. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific embodiments.

[0020] See Figure 1 A guide tube assembly 2 is installed inside the furnace body of the single crystal silicon furnace 1, and the guide tube assembly 2 divides the interior of the furnace body into two parts, an upper part and an lower part. A seed crystal 13 for pulling crystals and a lifting mechanism 14 for driving the seed crystal 13 to rise and fall are installed in the upper part 11 of the furnace body, and the guide tube surrounds the outside of the seed crystal 13; a crucible 15 for accommodating raw materials and a heating element 16 for heating the crucible 15 are provided in the lower part 12 of the furnace body. During operation, the heating element 16 first heats the raw materials in the crucible 15 until they melt, and then the seed crystal 13 moves downward under the drive of the lifting mechanism 14, passes through the tube of the guide tube assembly 2 and extends downward into the crucible 15, while the single crystal silicon solidifies on it, while moving upward under the drive of the lifting mechanism 14, it can be like Figure 1 As shown, a single crystal silicon rod 3 is pulled below the seed crystal 13. The seed crystal 13 pulls the single crystal silicon rod 3 above the guide tube assembly 2 for cooling. Once the single crystal silicon rod 3 cools and takes shape, the desired single crystal silicon rod 3 is obtained. The structure and operating principles of the seed crystal 13, lifting mechanism 14, crucible 15, and heating element 16 are all conventional and will not be described in detail here.

[0021] See the guide tube assembly 2 Figure 2 , including an outer guide tube 21 arranged on the outside and an inner guide tube 22 arranged on the inside. The outer guide tube 21 and the inner guide tube 22 are welded together at the top and bottom to form a vacuum heat-insulating cavity 23. In this way, although the outer guide tube 21 serves as the outer shell of the guide tube assembly 2, it is close to the crucible 15 (see FIG. 1 ) at the lower part 12 of the furnace body. Figure 1 ) and heating element 16 (see Figure 1) and other heat sources, resulting in a higher temperature. However, only a small portion of the heat from the outer guide tube 21 can be transferred to the inner guide tube 22 through heat conduction (i.e., the outer guide tube 21 can only conduct heat through the top and bottom portions of the outer guide tube 21 that are in contact with the inner guide tube 22, and the inner guide tube 22 is not easily heated as a result). In other embodiments, the heat insulation cavity 23 may not be vacuum-filled, but may instead be filled with a heat insulation material such as soft graphite felt or cured graphite felt.

[0022] The inner side surface 221 of the inner guide tube 22 is tilted upward and aligned with the upper part 11 of the furnace body, and the outer side surface 222 is tilted downward and aligned with the lower part 12 of the furnace body. Figure 3 An adhesive layer 223 is applied to the outer side surface 222 of the inner guide tube 22. The adhesive layer 223 is made of a high-temperature resistant adhesive material, such as silicon carbide adhesive, an adhesive composed of an inorganic ceramic material and a modified curing agent, or an adhesive composed of aluminosilicate and a modified curing agent. A heat radiation reflective layer 224 is spray-coated on the outer side of the adhesive layer 223. The heat radiation reflective layer 224 is housed in the heat-insulating cavity 23 and faces the outer guide tube 21. The heat radiation reflective layer 224 is a silver layer with a thickness of 3 to 50 μm. Figure 1 When the single crystal silicon furnace 1 is working, the crucible 15 and the heating element 16 located in the lower part 12 of the furnace body (even after a long period of operation, the outer guide tube 21 will become a heat source) will emit heat radiation toward the upper part 11 of the furnace body. These heat radiations pass through the outer side surface 222 of the inner guide tube 22 (see Figure 3 ) is reflected by the heat radiation reflecting layer 224 on the outer side 222 (see Figure 3 ) is reflected and returned to the lower portion 12 of the furnace body. The inner guide tube 22 thereby reduces the amount of heat radiation it receives from the heat source in the lower portion 12 of the furnace body, thereby reducing the amount of heat energy lost in the lower portion 12 of the furnace body and achieving an energy-saving effect. Because the inner guide tube 22 reduces the amount of heat radiation it receives from the heat source in the lower portion 12 of the furnace body, it is less likely to heat up and, therefore, less likely to emit heat radiation outward, thereby less likely to adversely affect the cooling and forming of the single crystal silicon rods 3 in the upper portion 11 of the furnace body. In this embodiment, the heat radiation reflecting layer 224 is adhered to the outer surface 222 via the adhesive layer 223, providing good adhesion. In other embodiments, the heat radiation reflecting layer 224 can be directly spray-coated onto the outer surface 222 of the inner guide tube 22.

[0023] The above is only an embodiment of the present invention and does not limit the scope of patent protection. Those skilled in the art can make non-substantial changes or substitutions based on the present invention and still fall within the scope of patent protection.

Claims

1. The energy-saving inner guide tube of the guide tube assembly of the single crystal silicon furnace has an inner side inclined upward and an outer side inclined downward, characterized in that: The outer surface is covered with a heat radiation reflecting layer, and an adhesive layer is provided between the outer surface and the heat radiation reflecting layer. The heat radiation reflecting layer is adhered to the outer surface through the adhesive layer. The heat radiation reflecting layer is a silver layer, and the thickness of the heat radiation reflecting layer is 3 to 50 μm.

2. A guide tube assembly for a single crystal silicon furnace, comprising an outer guide tube arranged on the outside and an inner guide tube arranged on the inside, wherein the outer guide tube and the inner guide tube are installed together, characterized in that: As described in claim 1 , the heat radiation reflecting layer of the inner guide tube faces the outer guide tube.

3. The guide tube assembly according to claim 2, wherein: The outer guide tube and the inner guide tube together form a heat-insulating cavity, and the heat radiation reflecting layer of the inner guide tube is accommodated in the heat-insulating cavity.

4. The guide tube assembly according to claim 3, wherein: The heat-insulating cavity is vacuum or filled with heat-insulating material.

5. A single crystal silicon furnace, wherein a seed crystal for crystal pulling is installed in the upper part of the furnace body and a heating element is installed in the lower part of the furnace body, and a guide tube assembly is provided between the seed crystal and the heating element, which surrounds the outer side of the seed crystal, characterized in that: The guide tube assembly is as described in any one of claims 2 to 4.

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