Crucible

Abstract

The present application discloses a crucible. The crucible is used in an ingot casting furnace, and the crucible includes a quartz ceramic body and a first silicon wafer layer, wherein the quartz ceramic body forms a heating groove; the first silicon wafer layer is laid on the bottom wall of the heating groove. In this way, when the crucible is used to heat granular silicon, the first silicon wafer layer will separate the quartz ceramic body from the granular silicon, thereby preventing the granular silicon from contacting the quartz ceramic body, thereby preventing the granular silicon from corroding the quartz ceramic body, causing the metal impurities in the quartz ceramic body to be released and contaminate the granular silicon.

Description

Technical Field

[0001] The present application relates to the technical field of ingot casting furnaces, and more specifically, to a crucible. Background Art

[0002] Quartz ceramic crucible is a ceramic crucible made of high-purity fused quartz. Quartz ceramic crucible can be used in polycrystalline ingot furnaces to serve as a container for polysiliconization and crystal growth. However, although the purity of quartz ceramic crucible is above 99.998%, it is far from the metal impurity level of granular silicon (below 1ppbw / one billionth). Granular silicon directly contacts quartz ceramic crucible, which is easy to corrode the quartz ceramic crucible. The metal impurities in the quartz ceramic crucible are released and pollute the granular silicon. Utility Model Content

[0003] An embodiment of the present application provides a crucible.

[0004] The crucible of the embodiment of the present application is used in an ingot casting furnace. The crucible comprises a quartz ceramic body and a first silicon wafer layer, wherein the quartz ceramic body forms a heating groove; and the first silicon wafer layer is laid on the bottom wall of the heating groove.

[0005] In this way, when the granular silicon is heated in a crucible, the first silicon wafer layer will separate the quartz ceramic body from the granular silicon, preventing the granular silicon from contacting the quartz ceramic body, thereby preventing the granular silicon from corroding the quartz ceramic body and causing the metal impurities in the quartz ceramic body to be released and contaminate the granular silicon.

[0006] In some embodiments, the first silicon wafer layer includes at least one of silicon wafers or recycled materials, and the recycled materials are scraps remaining from slicing round silicon rods formed by silicon crystal growth to form square silicon wafers.

[0007] In this way, the raw material of the first silicon wafer layer laid on the bottom wall of the heating tank can be silicon wafers or recycled materials. Since silicon wafers are finished products formed by slicing single crystal silicon rods formed after crystal pulling of granular silicon or block silicon, and recycled materials are scraps formed by slicing single crystal silicon rods. Therefore, silicon wafers are used as the raw material for the first silicon wafer layer, and can be directly laid in the heating tank without the need for other materials or steps, and will not interfere with the purity of granular silicon. Using recycled materials as the raw material for the first silicon wafer layer can recycle the recycled materials, thereby saving energy and costs.

[0008] In some embodiments, the thickness of the first silicon wafer layer ranges from 10 mm to 40 mm, and the silicon wafer size of the first silicon wafer layer ranges from 150 mm*150 mm to 250 mm*250 mm.

[0009] Thus, when the thickness of the first silicon wafer layer is less than 10 mm, the first silicon wafer layer is too thin, and when the granular silicon is heated, the first silicon wafer layer is easily melted, resulting in the granular silicon directly contacting the crucible and corroding the crucible, causing the metal in the crucible to be released and contaminate the silicon material; when the first silicon wafer is greater than 40 mm, although the first silicon wafer layer can be prevented from melting during the heating process, the first silicon wafer layer is too thick, which reduces the efficiency of heating the granular silicon and increases the material cost. By controlling the thickness of the first silicon wafer layer between 10 mm and 40 mm, the heating efficiency of the granular silicon can be ensured while avoiding the contact between the granular silicon and the inner wall of the crucible, thereby ensuring the purity of the granular silicon.

[0010] When the size of the silicon wafers in the first silicon wafer layer is less than 150 mm*150 mm, more silicon wafers are needed to cover the bottom wall of the heating tank, which increases the labor cost; when the size of the silicon wafer is greater than 250 mm*250 mm, the size is too large, resulting in too high difficulty in generating silicon rods of this size, thus affecting the efficiency of silicon rod generation and the stability of the silicon rod structure. By controlling the size of the silicon wafers in the first silicon wafer layer to 150 mm*150 mm to 250 mm*250 mm, the difficulty of generating and slicing silicon rods can be reduced, while the number of silicon wafers required to cover the bottom wall of the heating tank is moderate, reducing the consumption of labor costs.

[0011] In some embodiments, the crucible further includes a second silicon wafer layer, and the second silicon wafer layer paves the sidewall of the heating tank.

[0012] In this way, a second silicon wafer layer is provided on the side wall of the heating tank for isolating the granular silicon. Thus, when the granular silicon is heated by a crucible, the second silicon wafer layer will separate the quartz ceramic body from the granular silicon to prevent the granular silicon from contacting the quartz ceramic body, thereby preventing the granular silicon from corroding the quartz ceramic body and causing the metal impurities in the quartz ceramic body to be released and contaminate the granular silicon.

[0013] In some embodiments, the second silicon wafer layer includes at least one of silicon wafers or recycled materials, and the recycled materials are scraps remaining from slicing round silicon rods formed by silicon crystal growth to form square silicon wafers.

[0014] In this way, the raw material of the second silicon wafer layer laid on the bottom wall of the heating tank can be silicon wafers or recycled materials. Since silicon wafers are finished products formed by slicing single crystal silicon rods formed after crystal pulling of granular silicon or block silicon, and recycled materials are the scraps of silicon wafers formed by slicing single crystal silicon rods. Therefore, silicon wafers are used as the raw material for the second silicon wafer layer, which can be directly laid in the heating tank without the need for other materials or steps, and will not interfere with the purity of granular silicon. Using recycled materials as the raw material for the first silicon wafer layer can recycle the recycled materials, thereby saving energy and saving costs.

[0015] In some embodiments, the thickness of the second silicon wafer layer ranges from 10 mm to 40 mm, and the silicon wafer size of the second silicon wafer layer ranges from 150 mm*150 mm to 250 mm*250 mm.

[0016] Thus, when the thickness of the second silicon wafer layer is less than 10 mm, the second silicon wafer layer is too thin, and when the granular silicon is heated, the second silicon wafer layer is easily melted, resulting in the granular silicon directly contacting the crucible and corroding the crucible, causing the metal in the crucible to be released and contaminate the silicon material; when the thickness of the second silicon wafer is greater than 40 mm, although the second silicon wafer layer can be prevented from melting during the heating process, the second silicon wafer layer is too thick, which reduces the efficiency of heating the granular silicon and increases the material cost. By controlling the thickness of the second silicon wafer layer between 10 mm and 40 mm, the heating efficiency of the granular silicon can be ensured while avoiding the contact between the granular silicon and the inner wall of the crucible, thereby ensuring the purity of the granular silicon.

[0017] When the size of the silicon wafers in the second silicon wafer layer is less than 150 mm*150 mm, more silicon wafers are needed to cover the bottom wall of the heating tank, which increases the labor cost; when the size of the silicon wafer is greater than 250 mm*250 mm, the size is too large, resulting in too high difficulty in generating silicon rods of this size, thus affecting the efficiency of silicon rod generation and the stability of the silicon rod structure. By controlling the size of the silicon wafers in the second silicon wafer layer to 150 mm*150 mm to 250 mm*250 mm, the difficulty of generating and slicing silicon rods can be reduced, while the number of silicon wafers required to cover the bottom wall of the heating tank is moderate, reducing the consumption of labor costs.

[0018] In certain embodiments, the crucible includes a third silicon wafer layer, and the third silicon wafer layer seals an opening of the heating tank.

[0019] In this way, a third silicon wafer layer is provided at the opening of the heating tank for sealing the granular silicon. Thus, when the granular silicon is heated by a crucible, the third silicon wafer layer will separate the impurities in the hot field from the granular silicon. The granular silicon cannot directly contact the impurities in the hot field atmosphere, thereby reducing the contamination of the granular silicon.

[0020] In some embodiments, the third silicon wafer layer includes multiple layers of silicon wafers, and the silicon wafers are formed by slicing round silicon rods formed by growing silicon crystals.

[0021] In this way, the raw material of the third silicon wafer layer laid on the bottom wall of the heating tank can be a multi-layer silicon wafer. Since the silicon wafer is a finished product formed by slicing a single crystal silicon rod formed after crystal pulling of granular silicon or block silicon, the silicon wafer is used as the raw material of the third silicon wafer layer, which can be directly laid in the heating tank without the need for other materials or steps, and will not interfere with the purity of the granular silicon. Due to the limited thickness of the silicon wafer, the use of multi-layer silicon wafers can improve the stability of the third silicon wafer layer structure.

[0022] In some embodiments, the silicon wafers in different layers are stacked alternately to cover the gaps between the silicon wafers in the same layer.

[0023] In this way, since there are gaps between the silicon wafers of the same layer of the third silicon wafer layer, the gaps can allow impurities in the thermal field to fall into the heating tank and contaminate the granular silicon. Therefore, by staggered stacking of the multiple silicon wafers of the third silicon wafer layer to block the gaps between the silicon wafers of the same layer, impurities in the thermal field can be prevented from falling into the heating tank along the gaps between different layers and contaminating the granular silicon, thereby reducing the probability of the granular silicon being contaminated and improving the purity of the granular silicon.

[0024] In some embodiments, the thickness of the third silicon wafer layer ranges from 130 microns to 180 microns, and the silicon wafer size of the third silicon wafer layer ranges from 180 mm*180 mm to 220 mm*220 mm.

[0025] Thus, when the thickness of the third silicon wafer layer is less than 130 microns, the third silicon wafer layer is too thin, and when the granular silicon is heated, the third silicon wafer layer is easily melted, thereby causing impurities in the thermal field to fall into the heating tank and contaminate the granular silicon; when the thickness of the second silicon wafer is greater than 180 microns, although the third silicon wafer layer can be prevented from melting during the heating process, the third silicon wafer layer is too thick, which increases the material cost. By controlling the thickness of the third silicon wafer layer to between 130 microns and 180 microns, the heating tank can be sealed while saving costs, thereby ensuring the purity of the granular silicon.

[0026] When the size of the silicon wafers in the third silicon wafer layer is less than 180 microns * 180 microns, more silicon wafers are needed to seal the opening of the heating slot, which increases the labor cost and the difficulty of operation; when the size of the silicon wafer is greater than 220 mm * 220 mm, the size is too large, resulting in too high difficulty in generating silicon rods of this size, which affects the efficiency of silicon rod generation and the stability of the silicon rod structure. By controlling the size of the silicon wafers in the third silicon wafer layer to 180 mm * 180 mm to 220 mm * 220 mm, the difficulty of generating and slicing silicon rods can be reduced, while the number of silicon wafers required to seal the opening of the heating slot is moderate, reducing the consumption of labor costs and the difficulty of operation.

[0027] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1is a schematic structural diagram of an ingot casting furnace according to certain embodiments of the present application;

[0030] Figure 2 is a cross-sectional schematic diagram of a crucible according to certain embodiments of the present application;

[0031] Figure 3 is a top view of a crucible according to certain embodiments of the present application;

[0032] Figure 4 is a schematic cross-sectional view of a crucible according to certain embodiments of the present application.

[0033] Figure Number:

[0034] 100, ingot casting furnace; 10, crucible; 11, quartz ceramic body; 111, heating tank; 1111, bottom wall; 1112, side wall; 1113, opening; 12, first silicon wafer layer; 13, second silicon wafer layer; 14, third silicon wafer layer. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present application, and cannot be understood as limiting the embodiments of the present application.

[0036] In the description of the present application, it should be understood that the terms "thickness", "upper", "top", "bottom", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0037] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. In an example, it can be a fixed connection, or a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection, or they can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements.

[0038] In the embodiments of the present application, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] See also Figure 1 and Figure 2 The crucible 10 of the embodiment of the present application is used in an ingot casting furnace 100. The crucible 10 includes a quartz ceramic body 11 and a first silicon wafer layer 12. The quartz ceramic body 11 forms a heating groove 111; the first silicon wafer layer 12 is laid on the bottom wall 1111 of the heating groove 111.

[0040] In this way, when the crucible 10 is used to heat the granular silicon, the first silicon wafer layer 12 will separate the quartz ceramic body 11 from the granular silicon, preventing the granular silicon from contacting the quartz ceramic body 11, thereby preventing the granular silicon from corroding the quartz ceramic body 11 and causing the metal impurities in the quartz ceramic body 11 to be released and contaminate the granular silicon.

[0041] The ingot casting furnace 100 is a smelting device for melting silicon material and directionally solidifying it to generate polycrystalline silicon. The ingot casting furnace 100 includes a crucible 10, in which the melting and directionally solidification of the silicon material are both performed.

[0042] Specifically, the crucible 10 can be a high-purity fused quartz ceramic crucible 10, which is a ceramic crucible 10 made of high-purity fused quartz as a raw material, and the quartz ceramic crucible 10 can be used in the granular silicidation and crystal growth links in the single crystal furnace, serving as a container for loading granular silicon reactions.

[0043] When the raw material for producing polycrystalline silicon rods is granular silicon, the granular silicon will be in direct contact with the crucible 10. When the granular silicon melts during the material smelting stage, the granular silicon will erode the crucible 10, and the metal impurities in the crucible 10 will be released, contaminating the granular silicon, thereby reducing the purity of the generated polycrystalline silicon rods. Therefore, it is necessary to isolate the crucible 10 from the granular silicon to prevent the granular silicon from directly contacting the crucible 10 and corroding the crucible 10.

[0044] The crucible 10 includes a quartz ceramic body 11 and a first silicon wafer layer 12. The silicon dioxide content in the quartz ceramic body 11 is greater than 99.9%, and the shape of the quartz ceramic body 11 is square, which can form a heating groove 111. The opening 1113 of the heating groove 111 is perpendicular to the ground direction, so that granular silicon can enter the heating groove 111 from the opening 1113 of the heating groove 111, and the heating groove 111 can be used to heat the granular silicon.

[0045] The first silicon wafer layer 12 is laid on the bottom wall 1111 of the heating tank 111. When the granular silicon enters the heating tank 111 and is heated, the first silicon wafer layer 12 can isolate the granular silicon from contacting the bottom wall 1111 of the quartz ceramic body 11, thereby preventing the granular silicon from corroding the bottom wall 1111 of the quartz ceramic body 11.

[0046] See also Figure 3 In some embodiments, the first silicon wafer layer 12 includes at least one of silicon wafers or recycled materials, and the recycled materials are the scraps left over from the round silicon rods formed by the growth of silicon crystals to form square silicon wafers.

[0047] In this way, the raw material of the first silicon wafer layer 12 laid on the bottom wall 1111 of the heating tank 111 can be silicon wafers or recycled materials. Since silicon wafers are finished products formed by slicing single crystal silicon rods formed after crystal pulling of granular silicon or block silicon, and recycled materials are scraps formed by slicing single crystal silicon rods. Therefore, silicon wafers are used as the raw material for the first silicon wafer layer 12, and can be directly laid in the heating tank 111, without the need for other materials or steps, and will not interfere with the purity of the granular silicon. Using recycled materials as the raw material for the first silicon wafer layer 12 can recycle the recycled materials, thereby saving energy and saving costs.

[0048] Specifically, the first silicon wafer layer 12 is composed of at least one of silicon wafers or recycled materials. For example, the first silicon wafer layer 12 can be composed of silicon wafers; the first silicon wafer layer 12 can be composed of recycled materials; the first silicon wafer layer 12 can be composed of silicon wafers and recycled materials. Among them, the recycled materials can be the extra scraps when the round polycrystalline silicon rods formed by the growth of granular silicon or block silicon crystals are cut into square silicon wafers during the material cutting process.

[0049] The thickness of the first silicon wafer layer 12 ranges from 10 mm to 40 mm, and the size of the silicon wafer of the first silicon wafer layer 12 ranges from 150 mm*150 mm to 250 mm*250 mm. Thus, when the thickness of the first silicon wafer layer 12 is less than 10 mm, the first silicon wafer layer 12 is too thin, and when the granular silicon is heated, the first silicon wafer layer 12 is easily melted, thereby causing the granular silicon to directly contact the crucible 10 and corrode the crucible 10, so that the metal in the crucible 10 is released and contaminates the silicon material; when the first silicon wafer is greater than 40 mm, although the first silicon wafer layer 12 can be prevented from melting during the heating process, the first silicon wafer layer 12 is too thick, which reduces the efficiency of heating the granular silicon and increases the material cost. By controlling the thickness of the first silicon wafer layer 12 between 10 mm and 40 mm, the heating efficiency of the granular silicon can be ensured while avoiding the contact between the granular silicon and the inner wall of the crucible 10, thereby ensuring the purity of the granular silicon.

[0050] When the size of the silicon wafers in the first silicon wafer layer 12 is less than 150 mm*150 mm, more silicon wafers are needed to cover the bottom wall 1111 of the heating tank 111, thereby increasing the labor cost; when the size of the silicon wafer is greater than 250 mm*250 mm, due to the excessive size, it is too difficult to generate silicon rods of this size, thereby affecting the generation efficiency of the silicon rods and the stability of the silicon rod structure. By controlling the size of the silicon wafers in the first silicon wafer layer 12 to 150 mm*150 mm to 250 mm*250 mm, the difficulty of generating and slicing the silicon rods can be reduced, while the number of silicon wafers required to cover the bottom wall 1111 of the heating tank 111 is moderate, thereby reducing the consumption of labor costs.

[0051] See also Figure 2 and Figure 3 In some embodiments, the crucible 10 further includes a second silicon wafer layer 13 , and the second silicon wafer layer 13 is used to pave the side wall 1112 of the heating tank 111 .

[0052] In this way, a second silicon wafer layer 13 is provided on the side wall 1112 of the heating tank 111 for isolating the granular silicon, so that when the granular silicon is subjected to a heating process using the crucible 10, the second silicon wafer layer 13 will separate the quartz ceramic body 11 from the granular silicon to prevent the granular silicon from contacting the quartz ceramic body 11, thereby preventing the granular silicon from corroding the quartz ceramic body 11 and causing the metal impurities in the quartz ceramic body 11 to be released and contaminate the granular silicon.

[0053] Specifically, the crucible 10 also includes a second silicon wafer layer 13, which is laid on the side wall 1112 of the heating tank 111. When the granular silicon enters the heating tank 111 and is heated, the second silicon wafer layer 13 can isolate the granular silicon from direct contact with the side wall 1112 of the quartz ceramic body 11, thereby preventing the granular silicon from corroding the side wall 1112 of the quartz ceramic body 11.

[0054] See also Figure 3 In some embodiments, the second silicon wafer layer 13 includes at least one of silicon wafers or recycled materials, and the recycled materials are the scraps left over from the round silicon rods formed by the growth of silicon crystals to form square silicon wafers.

[0055] In this way, the raw material of the second silicon wafer layer 13 laid on the bottom wall 1111 of the heating tank 111 can be silicon wafers or recycled materials. Since silicon wafers are finished products formed by slicing single crystal silicon rods formed after crystal pulling of granular silicon or block silicon, and recycled materials are the scraps of silicon wafers formed by slicing single crystal silicon rods. Therefore, silicon wafers are used as the raw material for the second silicon wafer layer 13, which can be directly laid in the heating tank 111, without the need for other materials or steps, and will not interfere with the purity of granular silicon. Using recycled materials as the raw material for the first silicon wafer layer 12 can recycle the recycled materials, thereby saving energy and saving costs.

[0056] Specifically, the second silicon wafer layer 13 is composed of at least one of silicon wafers or recycled materials. For example, the second silicon wafer layer 13 can be composed of silicon wafers; the second silicon wafer layer 13 can be composed of recycled materials; the second silicon wafer layer 13 can be composed of silicon wafers and recycled materials. Among them, the recycled materials can be the extra scraps when cutting square silicon wafers from the round polycrystalline silicon rods formed by the growth of granular silicon or block silicon during the material cutting process. In the case where the second silicon wafer layer 13 is composed of silicon wafers, the silicon wafers can be stacked layer by layer along the direction of gravity to form the second silicon wafer layer 13.

[0057] The thickness of the second silicon wafer layer 13 ranges from 10 mm to 40 mm, and the size of the silicon wafer of the second silicon wafer layer 13 ranges from 150 mm*150 mm to 250 mm*250 mm. Thus, when the thickness of the second silicon wafer layer 13 is less than 10 mm, the second silicon wafer layer 13 is too thin, and when the granular silicon is heated, the second silicon wafer layer 13 is easily melted, thereby causing the granular silicon to directly contact the crucible 10 and corrode the crucible 10, so that the metal in the crucible 10 is released and contaminates the silicon material; when the thickness of the second silicon wafer is greater than 40 mm, although the second silicon wafer layer 13 can be prevented from melting during the heating process, the second silicon wafer layer 13 is too thick, which reduces the efficiency of heating the granular silicon and increases the material cost. By controlling the thickness of the second silicon wafer layer 13 between 10 mm and 40 mm, the heating efficiency of the granular silicon can be ensured while avoiding the contact between the granular silicon and the inner wall of the crucible 10, thereby ensuring the purity of the granular silicon.

[0058] When the size of the silicon wafers of the second silicon wafer layer 13 is less than 150 mm*150 mm, more silicon wafers are needed to cover the bottom wall 1111 of the heating tank 111, thereby increasing the labor cost; when the size of the silicon wafer is greater than 250 mm*250 mm, due to the excessive size, it is too difficult to generate silicon rods of this size, thereby affecting the generation efficiency of the silicon rods and the stability of the silicon rod structure. By controlling the size of the silicon wafers of the second silicon wafer layer 13 to 150 mm*150 mm to 250 mm*250 mm, the difficulty of generating and slicing the silicon rods can be reduced, while the number of silicon wafers required to cover the bottom wall 1111 of the heating tank 111 is moderate, thereby reducing the consumption of labor costs.

[0059] See also Figure 2 In some embodiments, the crucible 10 includes a third silicon wafer layer 14 , and the third silicon wafer layer 14 seals the opening 1113 of the heating tank 111 .

[0060] In this way, a third silicon wafer layer 14 is provided at the opening 1113 of the heating tank 111 for sealing the granular silicon. Thus, when the granular silicon is subjected to a heating process using the crucible 10, the third silicon wafer layer 14 will separate the impurities in the heat field from the granular silicon, and the granular silicon cannot directly contact the impurities in the heat field atmosphere, thereby reducing the contamination of the granular silicon.

[0061] Specifically, the crucible 10 also includes a third silicon wafer layer 14, which is laid at the opening 1113 of the heating tank 111. When the granular silicon enters the heating tank 111 and is heated, the third silicon wafer layer 14 can seal the granular silicon in the crucible 10, thereby preventing the granular silicon from contacting with impurities within the thermal field, thereby avoiding reducing the purity of the granular silicon.

[0062] See also Figure 4 In some embodiments, the third silicon wafer layer 14 includes multiple layers of silicon wafers, and the silicon wafers are formed by slicing round silicon rods formed by growing silicon crystals.

[0063] In this way, the raw material of the third silicon wafer layer 14 laid on the bottom wall 1111 of the heating tank 111 can be a multi-layer silicon wafer. Since the silicon wafer is a finished product formed by slicing a single crystal silicon rod formed after pulling granular silicon or block silicon, the silicon wafer is used as the raw material of the third silicon wafer layer 14, which can be directly laid in the heating tank 111 without requiring other materials or steps, and will not interfere with the purity of the granular silicon. Since the thickness of the silicon wafer is limited, the use of multi-layer silicon wafers can improve the stability of the structure of the third silicon wafer layer 14.

[0064] Specifically, the third silicon wafer layer 14 may be composed of multiple layers of silicon wafers, and the multiple layers of silicon wafers may be formed by slicing round polycrystalline silicon rods formed by crystal growth of granular silicon or block silicon.

[0065] After the granular silicon enters the heating tank 111 of the crucible 10, the granular silicon in the crucible 10 can be covered by covering the notch of the heating tank 111 with multiple layers of silicon wafers. Since there are gaps between the same layer of silicon wafers of the third silicon wafer layer 14, the gaps can allow impurities in the thermal field to fall into the heating tank 111 and contaminate the granular silicon. Therefore, by staggering and stacking the multiple layers of silicon wafers of the third silicon wafer layer 14 to block the gaps between the same layer of silicon wafers, impurities in the thermal field can be prevented from falling into the heating tank 111 along the gaps between different layers and contaminating the granular silicon, thereby reducing the probability of granular silicon being contaminated, thereby improving the purity of the granular silicon.

[0066] The thickness of the third silicon wafer layer 14 ranges from 130 microns to 180 microns, and the size of the silicon wafer of the third silicon wafer layer 14 ranges from 180 mm*180 mm to 220 mm*220 mm. In this way, when the thickness of the third silicon wafer layer 14 is less than 130 microns, the third silicon wafer layer 14 is too thin, and when the granular silicon is heated, the third silicon wafer layer 14 is easily melted, thereby causing impurities in the thermal field to fall into the heating tank 111 and contaminate the granular silicon; when the thickness of the second silicon wafer is greater than 180 microns, although the third silicon wafer layer 14 can be prevented from melting during the heating process, the third silicon wafer layer 14 is too thick, which increases the material cost. By controlling the thickness of the third silicon wafer layer 14 between 130 microns and 180 microns, the heating tank 111 can be sealed while saving costs, thereby ensuring the purity of the granular silicon.

[0067] When the size of the silicon wafers of the third silicon wafer layer 14 is less than 180 mm*180 mm, more silicon wafers are needed to seal the opening 1113 of the heating tank 111, thereby increasing the labor cost and the difficulty of operation; when the size of the silicon wafer is greater than 220 mm*220 mm, due to the excessive size, it is too difficult to generate silicon rods of this size, thereby affecting the generation efficiency of the silicon rods and the stability of the silicon rod structure. By controlling the size of the silicon wafers of the third silicon wafer layer 14 to 180 mm*180 mm to 220 mm*220 mm, the difficulty of generating and slicing the silicon rods can be reduced, while the number of silicon wafers required to seal the opening 1113 of the heating tank 111 is moderate, thereby reducing the consumption of labor costs and the difficulty of operation.

[0068] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one feature. In the description of this application, the meaning of "plurality" is at least two, such as two, three, unless otherwise clearly and specifically defined.

[0070] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A crucible for an ingot casting furnace, characterized in that: The crucible comprises: A quartz ceramic body, wherein the quartz ceramic body forms a heating tank; The first silicon wafer layer is laid on the bottom wall of the heating tank, and the first silicon wafer layer includes at least one of silicon wafers or recycled materials. The recycled materials are the residual scraps of the square silicon wafers formed by slicing round silicon rods formed by silicon material crystal growth.

2. The crucible according to claim 1, characterized in that The thickness of the first silicon wafer layer ranges from 10 mm to 40 mm, and the silicon wafer size of the first silicon wafer layer ranges from 150 mm*150 mm to 250 mm*250 mm.

3. The crucible according to claim 1, characterized in that The crucible further comprises a second silicon wafer layer, and the second silicon wafer layer is paved with a side wall of the heating tank.

4. The crucible according to claim 3, characterized in that The second silicon wafer layer includes at least one of silicon wafers or recycled materials, and the recycled materials are the residual scraps of the square silicon wafers formed by slicing round silicon rods formed by silicon material crystal growth.

5. The crucible according to claim 3, characterized in that The thickness of the second silicon wafer layer ranges from 10 mm to 40 mm, and the size of the silicon wafers of the second silicon wafer layer ranges from 150 mm*150 mm to 250 mm*250 mm.

6. The crucible according to claim 1, characterized in that The crucible includes a third silicon wafer layer, and the third silicon wafer layer seals the opening of the heating tank.

7. The crucible according to claim 6, characterized in that The third silicon wafer layer includes multiple layers of silicon wafers, and the silicon wafers are formed by slicing round silicon rods formed by growing silicon crystals.

8. The crucible according to claim 6, characterized in that The silicon wafers of different layers are stacked alternately to cover the gaps between the silicon wafers of the same layer.

9. The crucible according to claim 6, characterized in that The thickness of the third silicon wafer layer ranges from 130 microns to 180 microns, and the size of the silicon wafers of the third silicon wafer layer ranges from 180 mm*180 mm to 220 mm*220 mm.

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