Heat insulation structure, forming method thereof and monocrystalline silicon growth device

Abstract

The invention relates to a heat insulation structure, a forming method thereof and a monocrystalline silicon growth device. The invention provides a heat insulation structure. The heat insulation structure comprises a hot surface high-temperature-resistant layer and a heat insulation layer, wherein the hot surface high-temperature-resistant layer comprises a first surface and a second surface opposite to the first surface; the second surface of the hot surface layer is covered with the core heat insulation stacking layer, the core heat insulation stacking layer comprises a hot surface heat insulation layer covering the second surface of the hot surface high-temperature-resistant layer and a cold surface heat insulation layer located on the side, away from the hot surface high-temperature-resistant layer, of the hot surface heat insulation layer, and the hot surface heat insulation layer is a nano composite material layer comprising nano aerogel and ceramic fibers; the heat conductivity coefficient of the hot surface heat insulation layer is smaller than that of the cold surface heat insulation layer; and the cold surface supporting layer covers the surface, deviating from the hot surface high-temperature-resistant layer, of the core heat insulation stacking layer and is used for supporting the core heat insulation stacking layer. Heat loss such as heat conduction can be reduced to the maximum extent, energy consumption is reduced, and the production cost of semiconductor processes such as a monocrystalline silicon growth process is controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular to a heat insulation structure, a forming method thereof, and a single crystal silicon growth device. BACKGROUND

[0002] As a basic material for semiconductor devices, the market demand for silicon single crystals continues to rise with the rapid development of the electronic information industry. In the manufacturing process of silicon single crystals, the crystal growth furnace is the core production equipment, and its operation process needs to maintain a high-temperature environment to realize the melting, crystallization and growth of silicon raw materials, resulting in huge energy consumption.

[0003] In the growth process of semiconductor silicon single crystals, the energy consumption of the crystal growth furnace accounts for 40% to 60% of the total cost, which mainly comes from two aspects: on the one hand, the continuous power input required by the heater to maintain a high-temperature growth environment; on the other hand, the heat loss of the heat insulation system of the crystal growth furnace. The current heat insulation system of the crystal growth furnace mainly relies on the stacking of a single heat insulation material, which includes graphite, ceramic fiber, carbon fiber felt, etc. However, this single material stacking method has the following significant defects: first, the current single material has a relatively high thermal conductivity, which makes it difficult to achieve efficient heat insulation; second, the simple stacking of single materials does not consider the gradient characteristics of the thermal field distribution, resulting in uneven heat resistance distribution, which not only fails to effectively block the heat leakage of the high-temperature zone, but also causes material waste and aggravates heat loss; third, although there are heat insulation materials with low thermal conductivity, they lack a structure design that is suitable for the working environment of the crystal growth furnace, so they cannot form a systematic solution; fourth, some materials with better heat insulation performance have high costs, and simply increasing the thickness of single heat insulation materials to enhance the heat insulation effect will lead to an increase in the cost of silicon single crystal growth.

[0004] Therefore, how to enhance the heat insulation effect in the process of silicon single crystal growth, reduce the energy consumption of the crystal growth furnace in the process of silicon single crystal growth, and avoid the increase in the cost of silicon single crystal growth is a technical problem that needs to be solved at present. SUMMARY

[0005] The present application provides a heat insulation structure, a forming method thereof, and a single crystal silicon growth device for enhancing the heat insulation effect in the process of silicon single crystal growth, reducing the energy consumption of the crystal growth furnace in the process of silicon single crystal growth, and avoiding the increase in the cost of silicon single crystal growth.

[0006] According to some embodiments, the present application provides a heat insulation structure, comprising: a high-temperature-resistant layer on the hot surface, comprising a first surface facing the inside of the heating cavity and a second surface opposite to the first surface; a core thermal stack layer covering the second surface of the hot-face refractory layer, the core thermal stack layer comprising a hot-face thermal layer covering the second surface of the hot-face refractory layer and a cold-face thermal layer located on a side of the hot-face thermal layer away from the hot-face refractory layer, the hot-face thermal layer being a nanocomposite layer comprising nano-aerogel and ceramic fibers, and the hot-face thermal layer having a thermal conductivity less than that of the cold-face thermal layer; a cold-face support layer covering a surface of the core thermal stack layer away from the hot-face refractory layer for supporting the core thermal stack layer.

[0007] In some embodiments, the hot-face refractory layer is any one or a combination of a graphite layer and a first ceramic fiber layer.

[0008] In some embodiments, the nano-aerogel has a thermal conductivity less than or equal to 0.018 W / m·K, and the nanocomposite layer has a mass fraction of nano-aerogel greater than or equal to 70% and a mass fraction of ceramic fibers less than or equal to 30%.

[0009] In some embodiments, the nanocomposite layer further comprises carbon fibers.

[0010] In some embodiments, the core thermal stack layer further comprises an intermediate thermal layer between the hot-face thermal layer and the cold-face thermal layer. the hot-face thermal layer has a density less than that of the intermediate thermal layer, and the intermediate thermal layer has a density less than that of the cold-face thermal layer.

[0011] In some embodiments, the cold-face thermal layer is a carbon felt material layer, and the intermediate thermal layer comprises the nanocomposite layer and the carbon felt material layer alternately stacked in a direction of the hot-face refractory layer pointing to the cold-face support layer.

[0012] In some embodiments, the intermediate thermal layer has a thickness greater than that of the hot-face thermal layer, and the hot-face thermal layer has a thickness greater than or equal to that of the cold-face thermal layer.

[0013] In some embodiments, the cold-face support layer is a second ceramic fiber layer, and the second ceramic fiber layer has a mass fraction of alumina lower than that of the first ceramic fiber layer.

[0014] According to other embodiments, the present application further provides a method for forming the thermal insulation structure as described above, comprising the following steps: forming a hot-face refractory layer, the hot-face refractory layer comprising a first surface for facing the inside of a heating cavity and a second surface opposite to the first surface; forming the nano-aerogel by a sol-gel method or a vapor deposition method; mixing the nano-aerogel with ceramic fibers and forming a nano-composite layer as a hot-face thermal insulation layer by hot-pressing or spray drying; forming a cold-face thermal insulation layer, the thermal conductivity of the hot-face thermal insulation layer being less than that of the cold-face thermal insulation layer; forming a cold-face support layer; stacking the cold-face support layer, the cold-face thermal insulation layer, the hot-face thermal insulation layer and the hot-face high-temperature-resistant layer in sequence to form a thermal insulation structure.

[0015] In yet some embodiments, the present application also provides a single crystal silicon growth device, comprising: a crystal growth furnace comprising a furnace cavity for growing single crystal silicon; a thermal insulation structure as described above covering the inner wall of the furnace cavity, and the hot-face high-temperature-resistant layer in the thermal insulation structure facing the inside of the furnace cavity.

[0016] The thermal insulation structure and the method for forming the same, and the single crystal silicon growth device provided by the present application, by arranging the thermal insulation structure comprising a hot-face high-temperature-resistant layer, a core thermal insulation stack layer and a cold-face support layer, the hot-face high-temperature-resistant layer bears the high-temperature environment in the high-temperature furnace and blocks the damage of high temperature to the core thermal insulation stack layer, ensuring the stability of the thermal insulation performance of the core thermal insulation stack layer. The core thermal insulation stack layer as the core thermal insulation part of the thermal insulation structure comprises a hot-face thermal insulation layer covering the second surface of the hot-face layer and a cold-face thermal insulation layer covering the side of the hot-face thermal insulation layer away from the hot-face high-temperature-resistant layer, the hot-face thermal insulation layer is a nano-composite layer comprising nano-aerogel and ceramic fibers, and the thermal conductivity of the hot-face thermal insulation layer is less than that of the cold-face thermal insulation layer, thereby forming a gradient thermal insulation structure in the core thermal insulation stack layer, the gradient thermal insulation structure cooperates with the ultra-low thermal conductivity of the nano-composite material to optimize the thermal resistance distribution, maximally reduce the heat loss such as heat conduction, and enhances the thermal insulation effect on the high-temperature environment in the heating cavity, which is equivalent to reducing the energy consumption (for example, reducing the power consumption of the heater in the heating cavity by more than 30%), and controlling the production cost of the single crystal silicon growth process and other semiconductor processes. At the same time, by arranging the cold-face support layer on the side of the core thermal insulation stack layer away from the hot-face high-temperature-resistant layer, the core thermal insulation stack layer with the nano-composite layer can be supported, the stability of the whole thermal insulation structure is improved, and the heat exchange between the core thermal insulation stack layer and the external environment of the furnace is blocked, thereby further ensuring the thermal insulation effect of the thermal insulation structure.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the heat insulation structure in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the core thermal insulation stack layer in a specific embodiment of the present invention; Figure 3 This is a flowchart of the method for forming the heat insulation structure in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the single-crystal silicon growth apparatus in a specific embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures 10 Hot-face high-temperature resistant layer 101 First Surface 11-core thermal stack 12 Cold-faced support layers 20 hot surface insulation layer 21 Intermediate Insulation Layer 22 Cold-faced insulation layer 40 furnace chambers Detailed Implementation The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This specific embodiment provides a heat insulation structure. Figure 1 This is a schematic diagram of the heat insulation structure in a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the core thermal insulation stack layer in a specific embodiment of the present invention. For example... Figure 1 and Figure 2 As shown, the heat insulation structure includes: The high-temperature resistant hot surface layer 10 includes a first surface 101 facing the interior of the heating cavity and a second surface opposite to the first surface 101. The core thermal insulation stack 11 covers the second surface of the hot-side high-temperature resistant layer 10. The core thermal insulation stack 11 includes a hot-side thermal insulation layer 20 covering the second surface of the hot-side high-temperature resistant layer 10 and a cold-side thermal insulation layer 22 located on the side of the hot-side thermal insulation layer 20 away from the hot-side high-temperature resistant layer 10. The hot-side thermal insulation layer 20 is a nanocomposite material layer including nano-aerogel and ceramic fiber, and the thermal conductivity of the hot-side thermal insulation layer 20 is less than the thermal conductivity of the cold-side thermal insulation layer 22. The cold-side support layer 12 covers the surface of the core thermal insulation stack 11 away from the hot-side high-temperature resistant layer and is used to support the core thermal insulation stack 11.

[0022] Specifically, the thermal insulation structure includes a hot-side high-temperature resistant layer 10, a core thermal insulation stacked layer 11, and a cold-side support layer 12 stacked sequentially. The hot-side high-temperature resistant layer 10 includes a first surface 101 and a second surface distributed opposite to each other. The first surface 101 faces the heating cavity and is used to directly withstand the high-temperature environment inside the heating cavity. The second surface is in contact with the core thermal insulation stacked layer 11. The hot-side high-temperature resistant layer 10 is in direct contact with the high-temperature environment inside the heating cavity. On the one hand, this direct contact prevents the high-temperature environment inside the heating cavity from directly contacting the core thermal insulation stacked layer 11, thereby avoiding damage to the core thermal insulation stacked layer 11 and ensuring the stability of its thermal insulation performance. On the other hand, the hot-side high-temperature resistant layer 10 also blocks some heat loss.

[0023] The core thermal insulation stack 11 is sandwiched between the hot-side high-temperature resistant layer 10 and the cold-side support layer 12, and is the main part of the thermal insulation structure used to achieve thermal insulation and reduce heat loss. The core thermal insulation stack 11 includes at least the hot-side thermal insulation layer 20 and the cold-side thermal insulation layer 22. The hot-side thermal insulation layer 20 covers the second surface of the hot-side high-temperature resistant layer 10, and the cold-side thermal insulation layer 22 is located on the surface of the cold-side support layer 12 facing the hot-side high-temperature resistant layer 10, that is, the cold-side thermal insulation layer 22 is located between the hot-side thermal insulation layer 20 and the cold-side support layer 12. The hot-side thermal insulation layer 20 is a nanocomposite material layer including nano-aerogel and ceramic fiber. The nano-aerogel has an extremely low thermal conductivity, thereby making the thermal conductivity of the nanocomposite material layer low, becoming the main thermal insulation part in the core thermal insulation stack 11, which can significantly block heat from diffusing from the interior of the heating cavity towards the cold-side thermal insulation layer 22. Meanwhile, by adding ceramic fibers to the nanocomposite material layer, not only can the heat resistance and stability of the nanocomposite material layer structure be improved, but the problem of increased insulation cost caused by using only nano-aerogel as the hot-side insulation layer can also be solved. The thermal conductivity of the cold-side insulation layer 22 is greater than that of the hot-side insulation layer 20, thereby forming a gradient insulation structure in the core insulation stack 11. That is, the insulation effect of the core insulation stack 11 decreases gradually from the hot-side insulation layer 20 to the cold-side insulation layer 22. The gradient insulation structure, together with the ultra-low thermal conductivity of the nanocomposite material, can optimize the thermal resistance distribution, minimize heat loss such as heat conduction, and enhance the insulation effect. This is equivalent to reducing energy consumption and controlling the production cost of semiconductor processes such as single-crystal silicon growth. Moreover, by using a material with relatively high thermal conductivity to form the cold-side insulation layer 22, the high cost problem caused by using only nanocomposite material to form the core insulation structure can be avoided, thereby further helping to control the production cost of semiconductor processes.

[0024] By providing the cold-side support layer 12 on the side of the core insulation stack 11 away from the hot-side high-temperature resistant layer 10, the core insulation stack 11 with the nanocomposite material layer can be supported, improving the overall stability of the insulation structure. It can also assist in insulation, blocking heat exchange between the core insulation stack layer and the external environment of the furnace, thereby further ensuring the insulation effect of the insulation structure.

[0025] In some embodiments, the hot-surface high-temperature resistant layer 10 is any one of a graphite layer and a first ceramic fiber layer, or a combination of both.

[0026] For example, the first ceramic fiber layer is made of a high-temperature resistant ceramic material with good high-temperature resistance and chemical stability. In one example, the mass fraction of alumina in the high-temperature resistant ceramic material is greater than or equal to 48%. Since the main function of the hot-side high-temperature resistant layer 10 is to resist the high-temperature environment inside the heating cavity, using either the graphite layer or a combination of the first ceramic fiber layer as the hot-side high-temperature resistant layer 10 helps to improve its high-temperature resistance and enable it to withstand higher temperatures in the heating cavity. In one example, the purity of the graphite material in the graphite layer is greater than or equal to 99.9%.

[0027] In some embodiments, the thermal conductivity of the nanoaerogel is less than or equal to 0.018 W / m·K, and the mass fraction of the nanoaerogel in the nanocomposite layer is greater than or equal to 70%, while the mass fraction of the ceramic fiber is less than or equal to 30%.

[0028] In some embodiments, the nanocomposite layer further includes carbon fibers.

[0029] Specifically, the nanocomposite layer comprises 70% or more of nano-aerogel by mass, 30% or less of the ceramic fiber by mass, and a small amount of the carbon fiber. In one example, the ceramic fiber in the nanocomposite layer is made of the high-temperature resistant ceramic material. The nano-aerogel has a thermal conductivity of less than or equal to 0.018 W / m·K, which is an extremely low thermal conductivity material. Therefore, using the nano-aerogel as the main component of the nanocomposite layer can give the nanocomposite layer an overall low thermal conductivity, thereby effectively preventing heat from diffusing from the heating cavity to the outside and becoming the main heat insulation part of the insulation structure. By adding the high-temperature resistant ceramic fiber to the nanocomposite layer, the high-temperature resistance of the hot-surface insulation layer 20 can be further enhanced, so as to further prevent the high-temperature environment in the heating cavity from damaging the interior of the core insulation stack layer 11. Since the skeletal structure of the nano-aerogel is relatively loose, adding the carbon fiber to the nanocomposite layer can enhance the overall structural stability of the nanocomposite layer. In one example, the mass fraction of nanoaerogel in the nanocomposite layer is greater than or equal to 70%, the mass fraction of ceramic fiber is less than or equal to 25%, and the mass fraction of carbon fiber is less than or equal to 5%.

[0030] In some embodiments, the core insulation stack 11 further includes an intermediate insulation layer 21 located between the hot side insulation layer 20 and the cold side insulation layer 22; The density of the hot-side insulation layer 20 is less than the density of the intermediate insulation layer 21, and the density of the intermediate insulation layer 21 is less than the density of the cold-side insulation layer 22.

[0031] Specifically, the core thermal insulation stack 11 includes a hot-side thermal insulation layer 20, an intermediate thermal insulation layer 21, and a cold-side thermal insulation layer 22, stacked sequentially along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12. The density of the hot-side thermal insulation layer 20 is less than the density of the intermediate thermal insulation layer 21, and the density of the intermediate thermal insulation layer 21 is less than the density of the cold-side thermal insulation layer 22. That is, the density of the core thermal insulation stack 11 gradually increases along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12. In one example, the density of the hot-side thermal insulation layer 20 can be less than the density of the intermediate thermal insulation layer 21, and the density of the intermediate thermal insulation layer 21 can be less than the density of the cold-side thermal insulation layer 22, by making the porosity of the hot-side thermal insulation layer 20 greater than the porosity of the intermediate thermal insulation layer 21, and the porosity of the intermediate thermal insulation layer 21 greater than the porosity of the cold-side thermal insulation layer 22. By employing the nanocomposite material layer as the hot-side insulation layer 20 with high porosity (i.e., low density), and ensuring that the pores in the nano-aerogel are nanoscale closed pores, the higher porosity allows for the containment of more air with low thermal conductivity, further enhancing the insulation effect of the hot-side insulation layer and reducing heat loss. Along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12, the density of the core insulation stack layer 11 gradually increases, meaning the density or porosity of the core insulation layer 11 exhibits a gradient structure distribution. This results in a gradient distribution of the thermal conductivity of the core insulation stack layer 11, ensuring that the side of the core insulation stack layer 11 facing the hot-side high-temperature resistant layer 10 has a lower density or higher porosity, thus blocking gas convection. Furthermore, the higher density or lower porosity on the side of the core insulation stack layer 11 facing the cold-side support layer 12 prevents pore connectivity, suppressing convective heat loss. This optimizes the thermal resistance distribution and effectively suppresses heat loss within the heating cavity. Meanwhile, the core insulation layer 11 exhibits a gradient distribution in density or porosity, which improves the uniformity of temperature distribution within the heating cavity and stabilizes the thermal environment within the heating cavity. This stable thermal environment helps reduce defects during the monocrystalline silicon growth process, thereby improving the quality of monocrystalline silicon growth. Furthermore, the density of the core insulation stack 11 gradually increases along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12, meaning the core insulation layer 11 exhibits a gradient distribution in density or porosity. This also helps enhance the overall structural stability of the core insulation stack 11.

[0032] In some embodiments, the material of the cold-side insulation layer 22 is a carbon felt material layer, and the intermediate insulation layer 21 includes the nanocomposite material layer and the carbon felt material layer that are alternately stacked along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12.

[0033] In one example, the carbon felt material layer is a composite material layer comprising soft felt (e.g., carbon fiber soft felt) and carbon felt (e.g., ordinary carbon felt). Using this carbon felt material layer as the cold-side insulation layer 22 allows the cold-side insulation layer to possess both thermal barrier and structural support properties. The intermediate insulation layer 21 comprises alternating layers of the nanocomposite material and the carbon felt material layer stacked along the direction from the hot-side high-temperature resistant layer 10 to the cold-side support layer 12, facilitating a gradual transition (e.g., a gradual transition in density or porosity) from the hot-side insulation layer 20 to the cold-side insulation layer 22, avoiding abrupt structural changes that could affect the overall stability and thermal insulation of the core insulation stack.

[0034] In other embodiments, the material of the cold-surface insulation layer 22 may also be a high-density composite material, which refers to a composite material with a higher density than the nanocomposite material layer.

[0035] In some embodiments, the thickness of the intermediate insulation layer 21 is greater than the thickness of the hot-side insulation layer 20, and the thickness of the hot-side insulation layer 20 is greater than or equal to the thickness of the cold-side insulation layer 22, so as to further optimize thermal resistance.

[0036] In some embodiments, the cold surface support layer 12 is a second ceramic fiber layer, wherein the mass fraction of alumina in the second ceramic fiber layer is lower than the mass fraction of alumina in the first ceramic fiber layer.

[0037] Specifically, the cold-side support layer 12 is the second ceramic fiber layer. The mass fraction of alumina in the second ceramic fiber layer is lower than that in the first ceramic fiber layer, meaning that the high-temperature resistance of the second ceramic fiber layer is lower than that of the first ceramic fiber layer. In other words, the second ceramic fiber layer is a common, low-cost ceramic fiber. Since the cold-side support layer 12 does not directly face the high-temperature environment inside the heating cavity, using the second ceramic fiber layer as the cold-side support layer 12 helps to further reduce the cost of the entire insulation structure. Moreover, the second ceramic fiber layer can stably support the core insulation stack layer 11, thereby further improving the overall structural stability of the insulation structure.

[0038] This specific embodiment also provides a method for forming the heat insulation structure as described above. Figure 3This is a flowchart of a method for forming a heat insulation structure according to a specific embodiment of the present invention. A schematic diagram of the heat insulation structure can be found in [reference needed]. Figure 1 and Figure 2 .like Figures 1-3 As shown, the method for forming the thermal insulation structure includes the following steps: Step S31, forming a hot surface high temperature resistant layer 10, the hot surface high temperature resistant layer 10 including a first surface 101 facing the interior of the heating cavity and a second surface opposite to the first surface 101; Step S32: Form nano-aerogels using the sol-gel method or vapor deposition method; Step S33: The nano-aerogel is mixed with ceramic fibers and molded by hot pressing or spray drying to form a nano-composite layer as the thermal insulation layer 20. Step S34: A cold-side insulation layer 22 is formed, wherein the thermal conductivity of the hot-side insulation layer 20 is less than that of the cold-side insulation layer 22. Step S35, forming the cold surface support layer 12; Step S36: The cold side support layer 12, the cold side insulation layer 22, the hot side insulation layer 20 and the hot side high temperature resistant layer 10 are stacked and connected in sequence to form a heat insulation structure.

[0039] Specifically, the hot-side high-temperature resistant layer is formed using graphite or high-temperature resistant ceramic materials. Next, nano-aerogel is formed using a sol-gel method or vapor deposition, and the nano-aerogel is mixed with the high-temperature resistant ceramic fibers. This mixture is then hot-pressed or spray-dried to form a nanocomposite layer serving as the hot-side insulation layer 20. The cold-side insulation layer 22 is formed using a combination of soft felt (e.g., carbon fiber soft felt) and carbon felt (e.g., ordinary carbon felt), such that the thermal conductivity of the hot-side insulation layer 20 is less than that of the cold-side insulation layer 22. Then, the cold-side support layer 12 is formed using ordinary ceramic fibers (e.g., ceramic fibers with an alumina mass fraction of less than 40%). Subsequently, the cold-side support layer 12, the cold-side insulation layer 22, the hot-side insulation layer 20, and the hot-side high-temperature resistant layer 10 are sequentially stacked and connected, and the insulation structure is formed using a hot-pressing process.

[0040] This specific embodiment also provides a single-crystal silicon growth apparatus. Figure 4 This is a schematic diagram of the structure of the single-crystal silicon growth apparatus in a specific embodiment of the present invention. A schematic diagram of the heat insulation structure in the single-crystal silicon growth apparatus can be found in [reference needed]. Figure 1 and Figure 2 .like Figure 1 , Figure 2 and Figure 4 As shown, the single-crystal silicon growth apparatus includes: Crystal growth furnace, including furnace cavity 40 for growing single crystal silicon; The heat insulation structure described above covers the inner wall of the furnace cavity 40, and the heat-resistant layer 10 in the heat insulation structure faces the interior of the furnace cavity 40.

[0041] The thermal insulation structure and its formation method, as well as the single-crystal silicon growth apparatus provided in this specific embodiment, utilize a thermal insulation structure comprising a hot-side high-temperature resistant layer, a core thermal insulation stack layer, and a cold-side support layer. The hot-side high-temperature resistant layer withstands the high-temperature environment within the high-temperature furnace, preventing damage to the core thermal insulation stack layer and ensuring the stability of its thermal insulation performance. The core thermal insulation stack layer, as the core thermal insulation component of the thermal insulation structure, includes a hot-side thermal insulation layer covering the second surface of the hot-side layer and a cold-side thermal insulation layer covering the side of the hot-side thermal insulation layer facing away from the hot-side high-temperature resistant layer. The hot-side thermal insulation layer is a nanocomposite material layer comprising nano-aerogel and ceramic fibers, and its thermal conductivity is lower than that of the cold-side thermal insulation layer. This forms a gradient thermal insulation structure within the core thermal insulation stack layer. This gradient thermal insulation structure, combined with the ultra-low thermal conductivity of the nanocomposite material, optimizes thermal resistance distribution, minimizes heat loss such as heat conduction, enhances the thermal insulation effect, and effectively reduces energy consumption, thereby controlling the production costs of semiconductor processes such as single-crystal silicon growth. Meanwhile, by setting a cold-side support layer on the side of the core insulation stack layer away from the hot-side high-temperature resistant layer, the core insulation stack layer with the nanocomposite material layer can be supported, improving the overall stability of the insulation structure. It can also assist in insulation, blocking heat exchange between the core insulation stack layer and the external environment of the furnace, thereby further ensuring the insulation effect of the insulation structure.

[0042] It should be noted that references to "an embodiment," "an embodiment," "an exemplary embodiment," "some embodiments," etc., in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but each embodiment may not necessarily include that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure, or characteristic is described in connection with an embodiment, whether explicitly described or not, implementing such a feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0043] It should be noted that the terms "comprising" and "having," and their variations, used in this invention document are intended to cover non-exclusive inclusion. The terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, unless explicitly indicated by the context. It should be understood that such data used in this way can be interchanged where appropriate. Furthermore, embodiments and features in the embodiments of this invention can be combined with each other unless otherwise specified. In addition, descriptions of well-known components and technologies have been omitted in the above description to avoid unnecessarily obscuring the concepts of this invention. In the various embodiments described above, each embodiment focuses on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A heat insulation structure, characterized in that, include: The high-temperature resistant hot surface layer includes a first surface facing the interior of the heating cavity and a second surface opposite to the first surface; A core thermal insulation stack layer covers the second surface of the hot-side high-temperature resistant layer. The core thermal insulation stack layer includes a hot-side thermal insulation layer covering the second surface of the hot-side high-temperature resistant layer and a cold-side thermal insulation layer located on the side of the hot-side thermal insulation layer away from the hot-side high-temperature resistant layer. The hot-side thermal insulation layer is a nanocomposite material layer including nano-aerogel and ceramic fiber, and the thermal conductivity of the hot-side thermal insulation layer is less than that of the cold-side thermal insulation layer. A cold-side support layer covers the surface of the core thermal insulation stack layer that is away from the hot-side high-temperature resistant layer, and is used to support the core thermal insulation stack layer.

2. The heat insulation structure according to claim 1, characterized in that, The high-temperature resistant layer on the hot surface is any one of the graphite layer and the first ceramic fiber layer, or a combination of both.

3. The heat insulation structure according to claim 1, characterized in that, The thermal conductivity of the nano-aerogel is less than or equal to 0.018 W / m·K, and the mass fraction of the nano-aerogel in the nanocomposite layer is greater than or equal to 70%, while the mass fraction of the ceramic fiber is less than or equal to 30%.

4. The heat insulation structure according to claim 3, characterized in that, The nanocomposite layer also includes carbon fibers.

5. The heat insulation structure according to claim 1, characterized in that, The core insulation stack layer also includes an intermediate insulation layer located between the hot-side insulation layer and the cold-side insulation layer; The density of the hot-side insulation layer is less than the density of the intermediate insulation layer, and the density of the intermediate insulation layer is less than the density of the cold-side insulation layer.

6. The thermal insulation structure according to claim 5, characterized in that, The material of the cold side insulation layer is a carbon felt material layer, and the intermediate insulation layer includes the nanocomposite material layer and the carbon felt material layer that are alternately stacked along the direction from the hot side high temperature resistant layer to the cold side support layer.

7. The thermal insulation structure according to claim 6, characterized in that, The thickness of the intermediate insulation layer is greater than the thickness of the hot-side insulation layer, and the thickness of the hot-side insulation layer is greater than or equal to the thickness of the cold-side insulation layer.

8. The heat insulation structure according to claim 2, characterized in that, The cold-face support layer is a second ceramic fiber layer, and the mass fraction of alumina in the second ceramic fiber layer is lower than that in the first ceramic fiber layer.

9. A method for forming a thermal insulation structure as described in claim 1, characterized in that, Includes the following steps: A high-temperature resistant hot surface layer is formed, the high-temperature resistant hot surface layer including a first surface facing the interior of the heating cavity and a second surface opposite to the first surface; Nano-aerogels are formed by sol-gel method or vapor deposition method; The nano-aerogel is mixed with ceramic fibers and shaped by hot pressing or spray drying to form a nano-composite layer that serves as a thermal insulation layer on the hot side. A cold-side insulation layer is formed, wherein the thermal conductivity of the hot-side insulation layer is less than that of the cold-side insulation layer; Form a cold-face support layer; The cold-side support layer, the cold-side insulation layer, the hot-side insulation layer, and the hot-side high-temperature resistant layer are stacked and connected in sequence to form a heat insulation structure.

10. A single-crystal silicon growth apparatus, characterized in that, include: Crystal growth furnace, including a furnace cavity for growing single crystal silicon; The heat insulation structure as described in claim 1 covers the inner wall of the furnace cavity, and the heat-resistant layer of the heat insulation structure faces the interior of the furnace cavity.

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