Graphite crucible for single crystal furnace and its manufacturing method, crucible assembly and single crystal furnace

Abstract

A graphite crucible (100) for a single crystal furnace and its manufacturing method, a crucible assembly (1000), and a single crystal furnace, in which a groove (1b) is formed in a cutout portion (10), a semi-finished crucible (101), a quartz crucible (200) that fits the semi-finished crucible (101), and a molten metal (300) are subjected to a thermal field simulation to obtain an isotherm (R) of a high-temperature region of the molten metal (300), and the shape of the groove (1b) is configured to match the shape of a part of the isotherm (R) in a vertical cross section of the main body (1), and the semi-finished crucible (101) is configured to form the main body (1) by creating the groove (1b) on the inner wall surface of the semi-finished crucible (101).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Chinese patent application No. 202011519963.4, filed on December 21, 2020, and claims priority to the above-mentioned Chinese patent application, the entire contents of which are incorporated herein by reference. [Technical field]

[0002] The present application relates to the technical field of crucibles, in particular to a graphite crucible for a single crystal furnace and its manufacturing method, a crucible assembly and a single crystal furnace. [Background technology]

[0003] In the related art, the crucible assembly in the single crystal furnace includes a quartz crucible and a graphite crucible, and the crucible assembly contains raw materials, and the raw materials in the crucible assembly are melted into the silicon melt by the heating action of the heater in the single crystal furnace. Here, the oxygen in the silicon melt is mainly from the quartz crucible, and if the oxygen content of the melt is too high, it will cause a large amount of OISF and oxygen precipitation to occur in the crystal, especially because the temperature of the edge of the silicon melt is high, so that a lot of oxygen dissolves at the edge of the silicon melt during the whole crystal growth process, and the oxygen content at the edge of the silicon melt is too high, especially when there is no external magnetic field device, which will cause segregation phenomenon and affect the crystal quality. Summary of the Invention

[0004] The purpose of the present application is to solve at least one technical problem in the related art, and therefore the present application provides a graphite crucible for a single crystal furnace, which can reduce the heat conduction of the heater and the amount of heat diffused to the high temperature area of ​​the molten metal, and reduce the temperature of the edge part of the molten metal, thereby reducing the oxygen content of the molten metal and helping to improve the quality of the ingot.

[0005] The present application further provides a crucible assembly having the above-described graphite crucible.

[0006] The present application further provides a single crystal furnace having the above crucible assembly.

[0007] The present application further provides a method for making a graphite crucible.

[0008] A graphite crucible for a single crystal furnace according to a first aspect of the present application includes a body, the body being a graphite member, a receiving cavity is defined in the body, a wall surface of the receiving cavity has a notch portion, a groove is formed in the notch portion, the groove extends along a circumferential direction of the body to form an annular structure, a thermal field simulation is performed on a crucible semi-finished product, a quartz crucible fitted to the crucible semi-finished product, and a molten metal contained in the quartz crucible to obtain an isotherm of a high temperature region of the molten metal, a shape of the groove is configured to match a shape of a part of the isotherm in a longitudinal cross section of the body, the crucible semi-finished product is configured to form the body by creating the groove on an inner wall surface of the crucible semi-finished product, and a temperature of the high temperature region is higher than a temperature of any other region of the molten metal.

[0009] In the graphite crucible of the single crystal furnace of the present invention, a thermal field simulation is performed on the semi-finished crucible, the quartz crucible, and the molten metal to accurately obtain the isotherm of the high temperature region of the molten metal, and a groove is formed in the notch based on the shape of the isotherm. Therefore, when the graphite crucible is applied to the single crystal furnace, on the premise that the structural strength of the graphite crucible is ensured, the thermal conduction of the heater and the amount of heat diffused to the high temperature region of the molten metal can be reduced, and the temperature of the edge portion of the molten metal can be reduced, so that the oxygen content of the molten metal can be reduced and the crystal quality can be effectively improved.

[0010] In some embodiments, the graphite crucible is used for crystal pulling by a pulling method, and during the crystal pulling process, the isotherms are multiple and are arranged from top to bottom as the liquid level of the molten metal descends, and the areas on the wall of the crucible semi-finished product corresponding to the multiple isotherms are notch areas, and the notch portions are multiple and all are located within the notch areas.

[0011] In some embodiments, the plurality of cutout portions are spaced apart along an axial direction of the body and are configured to respectively correspond to a plurality of the isotherms, and a groove is formed in each of the cutout portions, and the shape of the groove is configured to match the shape of a portion of a corresponding isotherm.

[0012] In some embodiments, the cutouts are configured to be flush with the upper ends of the corresponding isotherms.

[0013] In some embodiments, the body includes a side wall portion and a bottom wall portion, the side wall portion is formed as a tubular structure, the bottom wall portion is connected to a bottom portion of the side wall portion to seal the bottom portion of the side wall portion, and the groove is formed in the side wall portion and / or the bottom wall portion.

[0014] In some embodiments, the groove is filled with a thermal insulating material, the thermal conductivity of the thermal insulating material being lower than the thermal conductivity of the body.

[0015] In some embodiments, the insulating member is a carbon fiber material member.

[0016] In some embodiments, the groove is configured to match the shape of the upper end of the isotherm.

[0017] The crucible assembly according to the second aspect of the present application includes a graphite crucible, which is the graphite crucible of the single crystal furnace according to the above first aspect of the present application, and a quartz crucible mounted in the receiving cavity.

[0018] Based on the crucible assembly of the present application, the use of the graphite crucible reduces the thermal conduction of the heater and the amount of heat diffused to the high temperature region of the molten metal, thereby reducing the temperature at the edge points of the molten metal, thereby reducing the oxygen content of the molten metal and helping to improve ingot quality.

[0019] A single crystal furnace according to a third aspect of the present application includes a furnace body and a crucible assembly according to the above second aspect of the present application, the crucible assembly being disposed within the furnace body.

[0020] Based on the single crystal furnace of the present application, the crucible assembly can be used to reduce the temperature at the edge of the molten metal, thereby reducing the oxygen content of the molten metal and helping to improve the quality of the ingot.

[0021] In a manufacturing method of a graphite crucible according to a fourth aspect of the present application, the graphite crucible is the graphite crucible of a single crystal furnace according to the above-mentioned first aspect of the present application, and the manufacturing method includes a step S1 of performing a thermal field simulation on a semi-finished crucible, a quartz crucible suitable for the semi-finished crucible, and a molten metal contained in the quartz crucible, a step S2 of extracting a result of the simulation in the step S1 and obtaining an isotherm of a high-temperature region of the molten metal, the temperature of the high-temperature region being higher than the temperature of any other region of the molten metal, and a step S3 of determining a shape of the groove based on a shape of the isotherm in a longitudinal section of the semi-finished crucible, creating the groove in the cutout portion, and forming the main body.

[0022] In the manufacturing method of the graphite crucible according to the present application, by performing thermal field simulation on the semi-finished crucible, the quartz crucible, and the molten metal, the isotherm of the high-temperature region of the molten metal can be accurately obtained, and the shape of the groove can be determined based on the isotherm, so as to reduce the thermal conduction of the heater and the amount of heat diffused to the high-temperature region of the molten metal, and to reduce the temperature of the edge portion of the molten metal, thereby reducing the oxygen content of the molten metal and helping to improve the quality of the ingot.

[0023] In some embodiments, in step S1, the crucible semi-finished product is used to perform a thermal field simulation in crystal pulling by a pulling method, so as to obtain a plurality of isotherms in step S2, the plurality of isotherms are arranged from top to bottom as the liquid level of the molten metal descends, and the area on the wall surface of the crucible semi-finished product corresponding to the plurality of isotherms is a cutout area, and step S3 further includes a step of determining a position of the cutout portion within the cutout area.

[0024] In some embodiments, the step of determining the position of the notch portion within the notch area includes the steps of: introducing the isotherms into a drawing of the crucible semi-finished product to determine the notch area; and selecting a portion of a plurality of the isotherms and determining the position of the notch portion based on the position of the selected isotherms.

[0025] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be apparent from the following description, or may be learned by practice of the present application. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram of a graphite crucible according to one embodiment of the present application. [Diagram 2] FIG. 2 is an enlarged view of a portion A indicated in a box in FIG. [Diagram 3] FIG. 2 is a schematic diagram of a crucible assembly according to one embodiment of the present application. [Figure 4] FIG. 4 is a locally enlarged view of the crucible assembly shown in FIG. [Diagram 5] FIG. 4 is a schematic diagram of isothermal lines of a high temperature region when heating a molten metal in the crucible assembly shown in FIG. 3. [Figure 6] FIG. 2 is a schematic flow diagram of a method for manufacturing a graphite crucible according to one embodiment of the present application. [Figure 7] FIG. 7 is a schematic diagram of creating a groove in the crucible blank shown in FIG. 6. [Figure 8]FIG. 2 is a schematic flow diagram of a method for manufacturing a graphite crucible according to another embodiment of the present application. [Figure 9] FIG. 1 is a schematic diagram of thermal field simulation results for three solutions: a semi-finished crucible (i.e., solution 1 without a groove), a graphite crucible in the present application with a groove and filled with a heat insulating material (solution 2), and a graphite crucible in the present application with a groove and not filled with a heat insulating material (solution 3). [Figure 10] FIG. 10 is a comparison diagram of isothermal lines in the high temperature region of the three solutions shown in FIG. [Figure 11] FIG. 10 is a comparison diagram of temperature distributions on the inner wall of the crucible in Solution 1 and Solution 2 shown in FIG. [Figure 12] FIG. 10 is a comparison diagram of oxygen contents at the edge of the molten metal of Solution 1 and Solution 2 shown in FIG. [Explanation of symbols]

[0027] Crucible assembly 1000, quartz crucible 200, molten metal 300, isotherm R, graphite crucible 100, central axis L, crucible semi-finished product 101, semi-finished product cavity 101a, main body 1, cutout portion 10, accommodation cavity 1a, groove 1b, hollow portion 1c, side wall portion 11, bottom wall portion 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments of the present application will be described in detail, and examples of the embodiments are shown in the drawings. Hereinafter, the same or similar symbols throughout represent the same or similar elements or elements having the same or similar functions. The following embodiments described with reference to the drawings are illustrative and are only used to interpret the present application, and are not intended to limit the present application.

[0029] The following disclosure provides different embodiments or configurations to achieve different structures of the present application. In order to simplify the disclosure of the present application, the following describes specific example components and configurations. Of course, they are illustrative and not limiting of the present application. The present application also repeatedly refers to numbers and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. The present application also provides examples of various processes and materials, but one of ordinary skill in the art can appreciate the applicability of other processes and / or other materials.

[0030] Hereinafter, a graphite crucible 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0031] As shown in Fig. 1, the graphite crucible 100 includes a body 1, the body 1 being a graphite member, a receiving cavity 1a being defined in the body 1, the receiving cavity 1a being used to receive raw materials, and after heating it, the raw materials in the receiving cavity 1a are melted into a molten metal 300. The wall surface of the receiving cavity 1a has a notch 10, and a groove 1b is formed in the notch 10, the groove 1b being formed in the inner wall surface of the body 1, and the groove 1b is formed by recessing a part of the wall surface of the receiving cavity 1a. Here, the groove 1b extends along the circumferential direction of the graphite crucible 100 to form a ring structure, which helps to ensure the structural strength of the graphite crucible 100.

[0032] For illustrative purposes, the graphite crucible 100 has a central axis L, and in the description of this application, the axial direction of the main body 1 is a direction along the central axis L of the graphite crucible 100, and the circumferential direction of the main body 1 is a direction around the central axis L of the graphite crucible 100. For example, in the example of FIG. 1, the graphite crucible 100 can be formed as a rotating structure, and the rotation center line of the rotating structure is the central axis L of the graphite crucible 100, and of course, the shape of the graphite crucible 100 is not limited thereto.

[0033] A thermal field simulation is performed on the semi-finished crucible 101, the quartz crucible 200 that fits the semi-finished crucible 101, and the molten metal 300 accommodated in the quartz crucible 200, and an isothermal line R of the high-temperature region of the molten metal 300 is obtained. In the longitudinal section of the main body 1, the shape of the groove 1b is configured to match the shape of a part of the isothermal line R. The semi-finished crucible 101 is configured to form the main body 1 by creating the groove 1b on the inner wall surface of the semi-finished crucible 101. The semi-finished crucible 101 is a graphite member. By defining a cavity 101a and creating a groove 1b on the wall of the semi-finished product cavity 101a, the body 1 can be formed; obviously, the semi-finished product cavity 101a corresponds to the receiving cavity 1a, and the difference between the semi-finished product cavity 101a and the receiving cavity 1a is whether a groove 1b is formed on the wall; the temperature of the high temperature area is higher than the temperature of any other area of ​​the molten metal 300, the high temperature area is the area of ​​the molten metal 300 with the highest temperature, and the high temperature area is located at the edge of the molten metal 300.

[0034] It should be understood that after creating the groove 1b in the crucible blank 101, the central axis of the crucible blank 101 can be formed as the central axis of the body 1. It can be understood that the longitudinal section of the body is a plane passing through the central axis L of the graphite crucible 100.

[0035] When the graphite crucible 100 is applied to a single crystal furnace, the receiving cavity 1a is suitable for mounting the quartz crucible 200, and the raw material is suitable for receiving in the quartz crucible 200. When the single crystal furnace is operated, the heater in the single crystal furnace heats the graphite crucible 100, the quartz crucible 200, and the raw material in the quartz crucible 200, and melts the raw material into molten metal 300. Since the graphite crucible 100 is provided on the radially outer side and / or the bottom side, the temperature of the high-temperature region at the edge (the outer edge and / or the bottom edge) of the molten metal 300 is the highest, which results in the oxygen content at the edge of the molten metal 300 being too high. According to the present application, a notch 10 is provided on the wall surface of the receiving cavity 1a, a groove 1b is formed in the notch 10, and the quartz crucible 2 When the quartz crucible 200 is attached to the graphite crucible 100, the outer wall surface of the quartz crucible 200 cannot contact or fit with the wall surface of the groove 1b, and the quartz crucible 200 and the groove 1b can define a cavity 1c (shown in FIG. 4), the thermal conductivity of which is much lower than that of graphite, i.e., the thermal conductivity of the cavity 1c is much lower than that of the body 1, which can reduce the amount of heat conducted from the heater and diffused to the edge portion of the molten metal 300, which is helpful in lowering the temperature of the edge portion of the molten metal 300. During the crystal growth process, the quartz crucible will decompose into oxygen atoms and silicon atoms in a high-temperature environment and enter the molten metal, which is helpful in reducing the oxygen dissolution rate at the edge of the molten metal 300, reducing the oxygen content, and further improving the ingot quality.

[0036] In addition, in the longitudinal section of the main body 1, the shape of the groove 1b is configured to match the shape of a part of the isotherm R of the high temperature region, and the shape of the groove 1b is provided according to the shape of the isotherm R of the high temperature region, so that the groove 1b matches the high temperature region, effectively reducing the area of ​​the high temperature region, and further effectively reducing the amount of heat conducted from the heater and diffused to the high temperature region of the molten metal 300, which is helpful in reducing the oxygen dissolution rate in the high temperature region of the molten metal 300, reducing the oxygen content, and effectively improving the quality of the ingot. 1. Since the structural strength of the crucible 101, quartz crucible 200, and molten metal 300 are different, the present application uses a simulation method for the crucible semi-finished product 101, the quartz crucible 200, and the molten metal 300 to accurately obtain the isotherm R of the high-temperature region of the molten metal 300, and further obtains the shape of the groove 1b accurately, so as to avoid the fact that a certain location is determined to be in the high-temperature region based on experience, when in fact it is not in the high-temperature region, which will affect the thermal field structure of the single crystal furnace and further affect the crystallization speed of the ingot.

[0037] Therefore, in the graphite crucible 100 of the single crystal furnace according to the present invention, by performing a thermal field simulation on the crucible semi-finished product 101, the quartz crucible 200, and the molten metal 300, the isotherm R of the high-temperature region of the molten metal 300 can be accurately obtained, and the shape of the groove 1b can be accurately obtained. Therefore, when the graphite crucible 100 is applied to a single crystal furnace, on the premise that the structural strength of the graphite crucible 100 is ensured, the thermal conduction of the heater and the amount of heat diffused to the high-temperature region of the molten metal 300 can be reduced, thereby reducing the temperature of the high-temperature region of the molten metal 300, and thus reducing the temperature of the edge portion of the molten metal 300, reducing the oxygen content of the molten metal 300, and further effectively improving the crystal quality.

[0038] In some embodiments, as shown in FIG. 5 , the graphite crucible 100 is used for pulling a crystal by a pulling method, and during the crystal pulling process, the level of the molten metal 300 gradually decreases, and the position of the isotherm R in the high temperature region is different at different stages or time points, and the graphite crucible 100 has multiple isotherms R during the crystal pulling process, and the multiple isotherms R are arranged from top to bottom as the level of the molten metal 300 decreases, and the regions on the wall surface of the crucible semi-finished product 101 corresponding to the multiple isotherms R are notched regions, or the crucible has multiple isotherms R at the multiple isotherms R. The area covered on the wall surface of the crucible semi-finished product 101 along the radial direction of the semi-finished product 101 is a notch area, and there are multiple notches 10, and the multiple notches 10 are all located within the notch area, so that the installation area of ​​the notch parts 10 can be accurately obtained based on the isotherm R, which simplifies the design of the position of the notch parts 10; at the same time, the multiple grooves 1b are also located within the notch area, which effectively ensures that different grooves 1b can play the role of reducing thermal conduction at different stages, and the grooves 1b can reduce thermal conduction during the entire crystal pulling process.

[0039] It should be understood that, in the entire crystal pulling process, if the length of the ingot changes continuously, the isotherm R also changes continuously, and there are an infinite number of isotherms R. The above pulling method is also called the Czochralski method, and may be a Czochralski method (CZ method), a continuous CZ method (CCZ method), or a Magnetic CZ method (MCZ method).

[0040] For example, the main body 1 includes a side wall portion 11 and a bottom wall portion 12, the side wall portion 11 is formed like a cylindrical structure, the bottom wall portion 12 is connected to the bottom of the side wall portion 11 to seal the bottom of the side wall portion 11, and when the heater of the single crystal furnace is provided only on the radial outside of the side wall portion 11, the high temperature region is located at the radially outer edge portion of the molten metal 300, and the multiple isotherms R are all arranged corresponding to the side wall portion 11. In this case, the multiple isotherms R are sequentially arranged from top to bottom along the axial direction of the main body 1, the notched region is located in the side wall portion 11, and the groove 1b is formed only in the side wall portion 11. When the heater of the single crystal furnace is provided only on the lower side of the bottom wall portion 12, the high temperature region is located at the bottom edge portion of the molten metal 300, and the multiple isotherms R are all arranged corresponding to the bottom wall portion 12. When the center of the corresponding curved surface is concave downward, the multiple isotherms R are still arranged sequentially from top to bottom as the liquid level of the molten metal 300 decreases, the cutout region is located in the bottom wall portion 12, and the groove 1b is formed only in the bottom wall portion 12. When the heater of the single crystal furnace includes a first heater provided on the radial outside of the side wall portion 11 and a second heater provided at the bottom of the bottom wall portion 12, the high temperature region is located at the radial outside edge portion of the molten metal 300, and when the power of the second heater is high, the high temperature region is also located at the edge portion of the bottom of the molten metal 300. In this case, the multiple isotherms R are arranged corresponding to the side wall portion 11 and the bottom wall portion 12, and the multiple isotherms R are also arranged sequentially from top to bottom, the cutout region is located in the side wall portion 11 and the bottom wall portion 12, and the groove 1b is formed in the side wall portion 11 and the bottom wall portion 12, respectively.

[0041] It should be understood that groove 1b is formed to be recessed along the thickness direction of main body 1, or groove 1b is formed to be recessed along the radial direction of main body 1; for example, when groove 1b is formed in side wall portion 11, groove 1b is formed to be recessed along the thickness direction of side wall portion 11, and when groove 1b is formed in bottom wall portion 12, groove 1b is formed to be recessed along the thickness direction of bottom wall portion 12.

[0042] In some embodiments, as shown in Figures 4 and 5, a plurality of notches 10 are spaced apart along the axial direction of the main body 1, and the plurality of notches 10 are configured to correspond to a plurality of isotherms R, and a groove 1b is formed in each notch 10, the grooves 1b are multiple, and the plurality of grooves 1b are spaced apart along the axial direction of the main body 1, which easily ensures the structural strength of the graphite crucible 100, and reduces the weakening effect of the grooves 1b on the main body 1, and there is a partition protrusion between two adjacent grooves 1b, and the end surface of the free end of the partition protrusion and the wall surface of the other accommodating cavity 1a on which the groove 1b is not formed are located on the same smooth curved surface.

[0043] For example, when the notch 10 is formed only in the side wall 11 of the main body 1, the multiple notch 10 are spaced apart along the axial direction of the main body 1, when the notch 10 is formed only in the bottom wall 12 of the main body 1, the central part of the curved surface corresponding to the inner wall of the bottom wall 12 is recessed downward, so the multiple notch 10 are also spaced apart along the axial direction of the main body 1, and when the notch 10 is formed in each of the side wall 11 and the bottom wall 12, all of the notch 10 are spaced apart along the axial direction of the main body 1. Of course, there may be only one notch 10, and in this case, there is only one groove 1b.

[0044] It should be understood that, under the condition that the strength requirements of the graphite crucible 100 are met, the depth of the groove 1b in the radial direction of the body 1 is as small as possible, and the width of the groove 1b in the axial direction of the body 1 is as large as possible, so that the groove 1b can effectively improve the function of reducing heat conduction, the temperature difference corresponding to any two adjacent ones of the multiple isotherms R in the selected high-temperature region can be specifically set according to actual needs, and the specific temperature value corresponding to each isotherm R can be specifically set according to actual needs. In the description of this application, "multiple" means two or more.

[0045] Here, the shape of the groove 1b is configured to match the shape of a part of the corresponding isotherm R. For example, a part of the isotherm R is selected, and the positions of the multiple notches 10 correspond one-to-one to the positions of the parts of the isotherm R, so that the position of each groove 1b can correspond to the position of the corresponding isotherm R. For example, in the axial direction of the crucible semi-finished product 101, the position of the notch 10 is flush with the upper end of the corresponding isotherm R, so that the position of the groove 1b can be determined based on the isotherm R, and the design of the position of the groove 1b can be easily simplified. Here, the shape of the groove is configured to match the shape of a part of the corresponding isotherm, and since the shape of the multiple isotherms R corresponding to the multiple notches 10 is generally different, the shape of the corresponding groove is determined based on the shape of the isotherm, and the shape of the groove is applied to actual production.

[0046] In some embodiments, as shown in FIGS. 1 and 5 , the notch 10 is configured to be flush with the upper end of the corresponding isotherm R, for example, the top end of the notch 10 can be flush with the top end of the corresponding isotherm R, and the position of the notch 10 can be quickly determined based on the position of the selected isotherm R; at the same time, the heater of the single crystal furnace includes a portion arranged radially outside the graphite crucible 100, and the top end of the isotherm R in the high-temperature region of the molten metal 300 has a protrusion, and the notch 10 and the protrusion are arranged correspondingly, which effectively reduces the temperature of the edge portion of the molten metal 300 and further reduces the oxygen content of the molten metal 300.

[0047] For example, when the notch 10 is formed in the side wall 11 of the main body 1, the corresponding isotherm R is arranged corresponding to the side wall 11, the tendency of the isotherm R is related to the shape of the inner wall of the side wall 11, the overall tendency of each isotherm R extends from top to bottom, and the notch 10 is configured to be flush with the upper end of the corresponding isotherm R, and when the notch 10 is formed in the bottom wall 12 of the main body 1, the corresponding isotherm R is arranged corresponding to the bottom wall 12, the tendency of the isotherm R is related to the shape of the inner wall of the bottom wall 12, the middle part of the curved surface corresponding to the inner wall of the bottom wall 12 is concave downward, so the overall tendency of each isotherm R extends from top to bottom, and the notch 10 is configured to be flush with the upper end of the corresponding isotherm R. Of course, the placement of the notch 10 is not limited to this.

[0048] In some embodiments, as shown in FIG. 1 , the main body 1 includes a side wall portion 11 and a bottom wall portion 12, the side wall portion 11 is formed as a tubular structure, the bottom wall portion 12 is connected to the bottom of the side wall portion 11 to seal the bottom of the side wall portion 11, and the groove 1b is formed in the side wall portion 11 and / or the bottom wall portion 12. For example, when the heater of the single crystal furnace is provided only on the radial outside of the graphite crucible 100, the groove 1b can be formed on the side wall 11; when the heater of the single crystal furnace includes a first heater provided on the radial outside of the graphite crucible 100 and a second heater provided on the bottom of the graphite crucible 100, when the power of the second heater is large, the high temperature position is located on the bottom of the graphite crucible 100, in which case the groove 1b is formed on the side wall 11 and the bottom wall 12, respectively. Therefore, the setting of the position of the groove 1b is flexible and can meet different actual needs.

[0049] As should be explained, in the description of the present application, the meaning of "and / or" refers to including three parallel solutions, and "A and / or B" as an example includes solution A, or solution B, or a solution that satisfies A and B simultaneously, and for example, groove 1b is formed in side wall portion 11 and / or bottom wall portion 12 includes: 1. groove 1b is formed in side wall portion 11 and groove 1b is not formed in bottom wall portion 12; 2. groove 1b is not formed in side wall portion 11 and groove 1b is formed in bottom wall portion 12; and 3. groove 1b is formed in side wall portion 11 and bottom wall portion 12, respectively.

[0050] Here, the term "tubular structure" should be understood in a broad sense, which includes, but is not limited to, cylindrical structures, conical structures, and polygonal tubular structures.

[0051] In some embodiments, an insulating material is filled in the groove 1b, and the thermal conductivity of the insulating material is lower than that of the main body 1, so that the groove 1b ensures reduced thermal conduction between the heater and the molten metal 300.

[0052] It should be understood that when there is one groove 1b, the groove 1b is filled with a heat insulating material, and when there are multiple grooves 1b, at least one of the multiple grooves 1b is filled with a heat insulating material.

[0053] Of course, there is no need to fill other materials in the groove 1b, and when the graphite crucible 100 is applied to a single crystal furnace, the quartz crucible 200 is attached to the receiving cavity 1a, and in this case, what is in the groove 1b is air, and the thermal conductivity of air is much lower than that of graphite, which can also play the role of reducing thermal conduction.

[0054] In some embodiments, the heat insulating component is a carbon fiber material component, which has obvious directional anisotropy, and in the direction perpendicular to the carbon fiber filaments, the carbon fiber material has low thermal conductivity and electrical conductivity, so that it has good heat preservation and heat insulation properties, and at the same time, the carbon fiber material component has good high temperature resistance, which ensures the reliability of the carbon fiber material component at high temperatures.

[0055] Of course, the insulating member may be made of other materials and is not limited to being made of carbon fiber material.

[0056] In some embodiments, as shown in FIG. 5, the upper end of the isotherm R has a curved portion to form a protrusion, and the shape of the groove 1b is configured to match the shape of the upper end of the isotherm R, thereby realizing the installation of the groove 1b.

[0057] It should be understood that when a notch 10 is formed in the side wall portion 11 of the main body 1, the overall trend of the corresponding isotherm R extends from top to bottom, and the groove 1b in the side wall portion 11 matches the shape of the upper end of the corresponding isotherm R, and when a notch 10 is formed in the bottom wall portion 12 of the main body 1, the overall trend of the corresponding isotherm R extends from top to bottom, and the groove 1b in the bottom wall portion 12 is configured to match the shape of the upper end of the corresponding isotherm R.

[0058] A crucible assembly 1000 according to an embodiment of the second aspect of the present application is shown in Fig. 3, the crucible assembly 1000 includes a graphite crucible 100 and a quartz crucible 200, the quartz crucible 200 is attached to the receiving cavity 1a of the graphite crucible 100. Here, the graphite crucible 100 is the graphite crucible 100 of the single crystal furnace according to the embodiment of the above-mentioned first aspect of the present application.

[0059] The crucible assembly 1000 according to the embodiment of the present application uses a graphite crucible 100, thereby reducing the temperature at the edge of the molten metal 300 in the crucible assembly 1000, and further reducing the oxygen content of the molten metal 300, thereby effectively improving the quality of the crystal, while ensuring the reliability of the crucible assembly 1000.

[0060] The single crystal furnace according to the embodiment of the third aspect of the present application includes a furnace body and a crucible assembly 1000, the crucible assembly 1000 being disposed within the furnace body, where the crucible assembly 1000 is a graphite crucible 1000 according to the embodiment of the above second aspect of the present application.

[0061] By using the crucible assembly 1000, the single crystal furnace according to the embodiment of the present application can reduce the temperature at the edge of the molten metal 300 in the crucible assembly 1000, thereby reducing the oxygen content of the molten metal 300 and improving the quality of the ingot produced in the single crystal furnace.

[0062] The remaining construction and operation of single crystal furnaces according to embodiments of the present disclosure are known to those of ordinary skill in the art and will not be described in detail herein.

[0063] In the method for manufacturing the graphite crucible 100 according to the embodiment of the fourth aspect of the present application, the graphite crucible 100 is the graphite crucible 100 of the single crystal furnace according to the embodiment of the first aspect of the present application, and the method for manufacturing the graphite crucible 100 includes the following steps: Step S1 of performing a thermal field simulation for the crucible semi-finished product 101, the quartz crucible 200 that fits the crucible semi-finished product 101, and the molten metal 300 contained in the quartz crucible 200; Step S2 of extracting the simulation results in step S1 and acquiring an isothermal line R of a high-temperature region of the molten metal 300, in which if the temperature of the high-temperature region is higher than the temperature of any other region of the molten metal 300, the high-temperature region is the region of the molten metal 300 with the highest temperature; and step S3 of determining the shape of the groove 1b based on the shape of the isotherm R in the longitudinal section of the semi-finished crucible 101, for example, the shape of the groove 1b in the longitudinal section of the semi-finished crucible 101 matches the shape of the upper end of the corresponding isotherm R, creating the groove 1b in the notch 10 to form the body 1. Obviously, the semi-finished crucible 101 is configured to create the groove 1b on the inner wall surface of the semi-finished crucible 101 to form the body 1, and the quartz crucible 200 may be adapted to the graphite crucible 100 in the present application.

[0064] It should be noted that each step is performed sequentially, and the order of each operation in the same step is not fixed. For example, steps S1, S2, and S3 are performed sequentially, and the "thermal field simulation" in step S1 is performed before the "acquisition of the isothermal curve R" in step S2.

[0065] Therefore, in the manufacturing method of the graphite crucible 100 according to the embodiment of the present application, by performing a thermal field simulation on the semi-finished crucible 101, the quartz crucible 200, and the molten metal 300, the isotherm R of the high-temperature region of the molten metal 300 can be accurately obtained, and the shape of the groove 1b can be determined based on the shape of the isotherm R, so as to reduce the thermal conduction of the heater and the amount of heat diffused to the high-temperature region of the molten metal 300, and to reduce the temperature of the edge portion of the molten metal 300, which in turn reduces the oxygen content of the molten metal and helps improve the quality of the ingot.

[0066] In some embodiments, the thermal field simulation in step S1 is performed in an ingot growth stage, where the parameters of the thermal field simulation can use the parameters of the ingot growth stage, so that the simulation result meets actual needs.

[0067] In some embodiments, in step S1, the crucible semi-finished product 101 is used to perform a thermal field simulation in crystal pulling by a pulling method, and in step S2, a number of isotherms R are obtained, the number of isotherms R are arranged from top to bottom as the liquid level of the molten metal 300 descends, and the area on the wall surface of the crucible semi-finished product 101 corresponding to the number of isotherms R is a notch area. Step S3 further includes a step of determining a position of the notch portion 10 within the notch area.

[0068] In some embodiments, the step of determining the position of the notch portion 10 within the cutout area includes the steps of introducing an isotherm R into a drawing of the crucible semi-finished product 101 and determining the cutout area; and selecting a portion of the multiple isotherms R and determining the position of the notch portion 10 based on the position of the selected isotherm R, for example, the multiple cutout portions 10 can be flush with the upper ends of the selected multiple isotherms R in one-to-one correspondence, thereby accurately and easily determining the positions of the notch portion 10 and the groove 1b.

[0069] For example, the isotherms R are introduced into the CAD drawing of the crucible semi-finished product in a ratio of 1:1, and the coordinates of any point on the isotherms R are the actual coordinates of the point, so that the notch area can be quickly determined based on the positions of the multiple isotherms R, and the multiple isotherms R can be reasonably selected to easily determine the position of the notch 10, which is convenient and fast. It should be understood that the specific temperature value indicated by the selected isotherm R can be selected according to actual needs.

[0070] As shown in FIG. 9 and FIG. 10, they show schematic diagrams of thermal field simulations of three solutions, namely, a crucible semi-finished product 101 (i.e., solution 1 without groove 1b), a graphite crucible 100 in the present application with groove 1b and a heat insulating member filled in groove 1b (solution 2), and a graphite crucible 100 in the present application with groove 1b and a material member not filled in groove 1b (solution 3). In FIG. 10, "200-first" corresponds to solution 1, and "200-fiber" corresponds to solution 2. " corresponds to solution 2, and "200-none" corresponds to solution 3. Also, Fig. 10 shows the isotherms of the high temperature area of ​​the molten metal of the three solutions in Fig. 9. As can be seen from the comparison, according to solution 2 and solution 3 of the present application, the area of ​​the high temperature area (≧1696.5K) is much lower than that of solution 1, and solution 3 is more significant, and when the high temperature area spreads downward, only a part of it is in the notch, so that the vacuum groove effectively reduces the amount of heat diffusing into the molten metal. Obviously, groove 1b effectively reduces the amount of heat transferred to the molten metal 300.

[0071] As shown in Figures 11 and 12, they show a comparison of the temperature distribution of the inner wall of the crucible and a comparison of the oxygen content at the edge of the molten metal for two solutions: a semi-finished crucible (i.e., Solution 1 in which groove 1b is not provided) and one in which an insulating material is filled in groove 1b (Solution 2). As can be seen from these, the temperature of the high-temperature region of Solution 2 is 1 to 2°C lower than Solution 1, and the oxygen content at the edge of the molten metal is correspondingly reduced, and the correlation between the temperature of the high-temperature region and the release of oxygen from the crucible is clear.

[0072] In the description of this application, as necessary for the description, the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "thickness", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are used only to explain and simplify the description of this application, and do not indicate or imply that the devices or elements referred to have a particular orientation and must be constructed and operated in a particular direction, and therefore, they should not be construed as limitations on this application. Note that a feature delimited by "first" and "second" may include one or more of the features explicitly or implicitly.

[0073] In the present description, as should be explained, unless otherwise specified, the terms "attached", "connected" and "coupled" should be understood in a broad sense, for example, "coupled" may be a fixed, detachable or integral connection, may be a mechanical or electrical connection, may be a direct connection or an indirect connection through an intermediate medium, and may be a communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application in a specific context.

[0074] As used herein, the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," "particular examples," or "some examples" and the like refer to the inclusion of a particular feature, structure, material, or characteristic described with reference to that embodiment or example in at least one embodiment or example of the present application. As used herein, general descriptions of such terms do not necessarily refer to the same embodiment or example. Also, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0075] Although examples of the present application are shown and described, those skilled in the art can make various changes, modifications, substitutions and variations to these examples without departing from the principles and intent of the present application, and it can be understood that the scope of the present application is limited by the claims and their equivalents.

Claims

1. A graphite crucible for a single crystal furnace, comprising: a body, the body being a graphite member, a receiving cavity being defined in the body, the receiving cavity having a wall surface with a notch, the notch having a groove formed therein, the groove extending along a circumferential direction of the body to form an annular structure; A graphite crucible for a single crystal furnace, comprising: a crucible semi-finished product, a quartz crucible fitted to the crucible semi-finished product, and a molten metal contained in the quartz crucible; a thermal field simulation is performed on a crucible semi-finished product, and an isothermal line of a high temperature region of the molten metal is obtained; in a longitudinal section of the body, a shape of the groove is configured to match a shape of an upper end of the isothermal line; the crucible semi-finished product is configured to form the body by creating the groove on an inner wall surface of the crucible semi-finished product; and a temperature of the high temperature region is higher than a temperature of any other region of the molten metal.

2. 2. The graphite crucible for a single crystal furnace according to claim 1, wherein the graphite crucible is used for pulling a crystal by a pulling method, and during a crystal pulling process, the isotherms are multiple and are arranged from top to bottom as the liquid level of the molten metal descends, and the regions on the wall surface of the semi-finished crucible corresponding to the multiple isotherms are notched regions, and the notched portions are multiple and all are located within the notched regions.

3. 3. The graphite crucible for a single crystal furnace according to claim 2, wherein the plurality of notches are spaced apart along the axial direction of the body and are configured to correspond to the plurality of isotherms, respectively, the groove is formed in each of the notches, and the shape of the groove is configured to match the shape of a portion of the corresponding isotherm.

4. 4. The graphite crucible of claim 3, wherein the notch is configured to be flush with an upper end of a corresponding isotherm.

5. The graphite crucible of the single crystal furnace according to any one of claims 1 to 4, wherein the main body includes a side wall portion and a bottom wall portion, the side wall portion is formed as a cylindrical structure, the bottom wall portion is connected to the bottom of the side wall portion to seal the bottom of the side wall portion, and the groove is formed in the side wall portion and / or the bottom wall portion.

6. 6. The graphite crucible for a single crystal furnace according to claim 5, wherein the groove is filled with a heat insulating material, and the heat conductivity of the heat insulating material is lower than the heat conductivity of the main body.

7. 7. The graphite crucible of claim 6, wherein the heat insulating member is a carbon fiber material member.

8. A graphite crucible for a single crystal furnace according to any one of claims 1 to 7; a quartz crucible mounted in the receiving cavity.

9. The furnace body, and the crucible assembly according to claim 8 provided in said furnace body.

10. A method for producing a graphite crucible for a single crystal furnace according to any one of claims 1 to 7, comprising the steps of: Step S1 of performing a thermal field simulation on a crucible semi-finished product, a quartz crucible that fits the crucible semi-finished product, and a molten metal contained in the quartz crucible; Step S2 of extracting the simulation results from step S1 and acquiring an isothermal line of a high-temperature region of the molten metal, the temperature of the high-temperature region being higher than the temperature of any other region of the molten metal; and step S3 of determining a shape of the groove based on a shape of the isotherm in a vertical cross section of the semi-finished crucible, creating the groove in the notch portion, and forming the body.

11. In the step S1, the crucible semi-finished product is used to perform a thermal field simulation in crystal pulling by a pulling method, so that a plurality of isotherms are obtained in the step S2, the plurality of isotherms are arranged from top to bottom as the liquid level of the molten metal descends, and the region on the wall surface of the crucible semi-finished product corresponding to the plurality of isotherms is a notch region; The method for manufacturing a graphite crucible according to claim 10, wherein step S3 further comprises determining a position of the notch portion within the notch region.

12. The step of determining a position of the cutout within the cutout region includes: introducing said isotherm into a drawing of said crucible semi-finished product and determining said cut-out area; and selecting a portion of the plurality of isothermal lines and determining a position of the notch portion based on a position of the selected isothermal line.

Images