Crystal manufacturing apparatus and crystal manufacturing method

Abstract

A crystal manufacturing apparatus (100) and a crystal manufacturing method (700) are disclosed. The crystal manufacturing apparatus (100) includes a growth chamber (110) provided with at least one layer of plate assembly (111), and a heating assembly (120) for heating the growth chamber (110). The crystal manufacturing method (700) includes a step (710) of disposing a raw material in a growth chamber (110) provided with at least one layer of plate assembly (111), a step (720) of heating the growth chamber (110) by a heating assembly (120) so that the raw material melts into a melt, a step (730) of bonding a seed crystal (180) to a seed crystal holder (150), a step of lowering the seed crystal holder (150) to which the seed crystal (180) is bonded so that the seed crystal (180) contacts the melt (740), and a step of manufacturing a crystal (750) based on the seed crystal (180) and the melt.

Description

Technical Field

[0001] This specification relates to the technical field of crystal manufacturing, and particularly to an apparatus and method for manufacturing crystals based on the liquid phase method.

Background Art

[0002] When manufacturing crystals (for example, silicon carbide) based on the liquid phase method (for example, liquid phase epitaxy (LPE)), the volatile components in the raw material move upward, further evaporate into a gaseous state, continuously overflow and reach the external heat insulation assembly, causing excessive consumption of the raw material, causing deviation of the components in the raw material during the evaporation process, and affecting crystal growth. In addition, the overflowed vapor affects the heat insulation performance of the heat insulation assembly. Therefore, it is necessary to provide a crystal manufacturing apparatus that improves the movement situation of volatile components and further guarantees the normal growth of crystals.

Summary of the Invention

[0003] One embodiment of this specification provides a crystal manufacturing apparatus. The crystal manufacturing apparatus includes a growth chamber provided with at least one layer of plate assembly inside, and a heating assembly for heating the growth chamber.

[0004] In some embodiments, the plate assembly includes through holes.

[0005] In some embodiments, the through holes of the adjacent plate assemblies are offset from each other.

[0006] In some embodiments, for at least one of at least one layer of the plate assemblies, the ratio of the total opening area of the through holes to the upper surface area of the plate assembly is within the range of 30% to 80%.

[0007] In some embodiments, the density of the through holes gradually decreases from the center to the edge of the plate assembly.

[0008] In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly to the density of the through-holes near the edge of the plate assembly is in the range of 1:1 to 20:1.

[0009] In some embodiments, the diameter of the through-holes is in the range of 0.1 mm to 10 mm.

[0010] In some embodiments, the plate assembly is located in the melt within the growth chamber and is located at a predetermined distance below the liquid surface of the melt.

[0011] In some embodiments, the distance between adjacent plate assemblies is in the range of 10 mm to 60 mm.

[0012] In some embodiments, a coating is applied or a shielding ring is provided in a predetermined upper range of the side wall of the growth chamber.

[0013] In some embodiments, the predetermined upper range is in the range of 0 to 2 / 3 along the height direction of the growth chamber.

[0014] In some embodiments, the apparatus further includes a chamber cover and an upper heat insulating member, and a carbon powder is filled in the gap between the chamber cover and the upper heat insulating member.

[0015] In some embodiments, the chamber cover includes a protrusion structure.

[0016] In some embodiments, the thickness of the side wall of the growth chamber gradually increases along the direction from the top to the bottom of the growth chamber.

[0017] In some embodiments, the heating assembly includes an induction coil, the induction coil is disposed around the outer periphery of the growth chamber, and the ratio of the height of the growth chamber to the induction coil is in the range of 1:1 to 1:5.

[0018] In some embodiments, the apparatus further includes a seed crystal holder that bonds seed crystals including at least two layers of seed crystals.

[0019] In some embodiments, the at least two layers of seed crystals include a first seed crystal and a second seed crystal. The first seed crystal is bonded to the seed crystal holder, the second seed crystal is bonded to the first seed crystal, and the mass of the first seed crystal is smaller than the mass of the second seed crystal.

[0020] In some embodiments, graphite paper is filled between the seed crystal holder and the seed crystal.

[0021] One embodiment of the present specification also provides a crystal manufacturing method. The method includes the steps of disposing a raw material in a growth chamber provided with at least one layer of plate assembly therein, heating the growth chamber by a heating assembly so that the raw material melts into a melt, bonding a seed crystal to a seed crystal holder, lowering the seed crystal holder to which the seed crystal is bonded so that the seed crystal contacts the melt, and manufacturing a crystal based on the seed crystal and the melt.

[0022] In some embodiments, the seed crystal includes at least two layers of seed crystals. The at least two layers of seed crystals include a first seed crystal and a second seed crystal. The first seed crystal is bonded to the seed crystal holder, the second seed crystal is bonded to the first seed crystal, and the mass of the first seed crystal is smaller than the mass of the second seed crystal.

[0023] In some embodiments, graphite paper is filled between the seed crystal holder and the seed crystal.

[0024] In some embodiments, the ratio of the height of the melt to the growth chamber is in the range of 1:1 to 1:5.

Brief Description of the Drawings

[0025] This specification is further illustrated by exemplary embodiments, which are described in detail by the drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures.

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0027] To more clearly explain the technical means of the embodiments of this specification, the drawings necessary for the description of the embodiments are briefly explained below. Obviously, the drawings described below are only some examples or embodiments of this specification, and those skilled in the art can apply this specification to other similar situations based on these drawings without creative labor. Unless it is clear from the context or otherwise stated, the same numbers in the figures represent the same structures or operations.

[0028] It should be understood that the terms "system", "device", "unit" and / or "module" used in this specification are a way to distinguish various assemblies, components, members, parts or assemblies at different levels. However, other expressions can be used in place of the above terms if other terms can achieve the same purpose.

[0029] As shown in this specification and the claims, unless the context clearly indicates otherwise, terms such as "one", "a", "a kind" and / or "the" do not particularly mean the singular form and may include the plural form. Generally, the terms "comprising" and "containing" merely present that they include the specifically identified steps and elements, and these steps and elements are not an exclusive listing, and the method or device may also include other steps or elements.

[0030] FIG. 1 is a schematic configuration diagram of an exemplary crystal manufacturing apparatus according to some embodiments of this specification.

[0031] In some embodiments, the crystal manufacturing apparatus 100 can manufacture crystals (for example, silicon carbide) based on the liquid phase method. Hereinafter, with reference to the drawings, taking the manufacture of silicon carbide crystals as an example, the crystal manufacturing apparatus 100 according to the embodiments of this specification will be described in detail. It should be noted that the following embodiments are only for interpreting this specification and do not limit this application.

[0032] As shown in FIG. 1, the crystal manufacturing apparatus 100 may include a growth chamber 110 and a heating assembly 120.

[0033] The temperature field growth chamber 110 functions as a place for manufacturing crystals, and the heating assembly 120 is used to heat the growth chamber 110 to provide the heat (for example, temperature, temperature field, etc.) required for crystal manufacturing.

[0034] In some embodiments, the material of the growth chamber 110 may be determined according to the type of crystal to be manufactured. For example, when manufacturing a silicon carbide crystal, the material of the growth chamber 110 may include graphite. In some embodiments, the material of the growth chamber 110 may include molybdenum, tungsten, tantalum, etc. In some embodiments, the growth chamber 110 can provide the raw materials necessary for crystal manufacturing. For example, the growth chamber 110 can provide the carbon necessary for the manufacture of silicon carbide crystals as a carbon source. In some embodiments, raw materials (e.g., silicon powder, carbon powder) necessary for crystal manufacturing may be arranged inside the growth chamber 110. In some embodiments, the growth chamber 110 may be a place where the raw materials are formed into a melt. For example, under the high temperature generated by the heating assembly 120, the silicon powder melts into a melt, and the carbon provided by the growth chamber 110 itself melts into the silicon solution to form a solution containing carbon and silicon, which is used as the liquid raw material for manufacturing silicon carbide crystals by the liquid phase method. In some embodiments, in order to improve the solubility of carbon in silicon, a flux (e.g., aluminum alloy, silicon chromium alloy, Li-Si alloy, Ti-Si alloy, Fe-Si alloy, Sc-Si alloy, Co-Si alloy, etc.) may be added to the raw materials.

[0035] In some embodiments, in order to avoid the silicon near the surface of the melt reacting with the carbon on the side wall of the growth chamber 110 to spontaneously nucleate, crystallize, and grow, a coating may be applied or a shielding ring may be provided in a predetermined upper range of the inner wall of the growth chamber 110. In some embodiments, the material of the coating or the shielding ring may be a high-temperature resistant metal (e.g., rare earth metals such as tungsten, tantalum, molybdenum, chromium, etc., aluminum) or a metal compound (e.g., zirconium oxide, aluminum oxide, etc.).

[0036] In some embodiments, the upper predetermined range may be in the range of 0 to 2 / 3 along the height direction of the growth chamber. In some embodiments, the upper predetermined range may be in the range of 0 to 1 / 3 along the height direction of the growth chamber. In some embodiments, the upper predetermined range may be in the range of 0 to 1 / 4 along the height direction of the growth chamber.

[0037] For more descriptions of the growth chamber 110, reference can be made to other parts of this specification (for example, FIG. 5 and its description), so the description is omitted here.

[0038] In some embodiments, the heating assembly 120 may include an induction heating assembly, a resistance heating assembly, etc. In some embodiments, the heating assembly 120 may be provided around the outer periphery of the growth chamber of the growth chamber 110.

[0039] In some embodiments, the heating assembly 120 may include an induction coil. In some embodiments, the induction coil may be provided around the outer periphery of the growth chamber 110. In some embodiments, in order to ensure the temperature field required for crystal growth and improve the crystal growth efficiency, it is necessary to make the ratio of the height between the growth chamber 110 and the induction coil within a predetermined range.

[0040] In some embodiments, the ratio of the height between the growth chamber 110 and the induction coil may be in the range of 1:1 to 1:5. In some embodiments, the ratio of the height between the growth chamber 110 and the induction coil may be in the range of 1:1.5 to 1:4.5. In some embodiments, the ratio of the height between the growth chamber 110 and the induction coil may be in the range of 1:2 to 1:4. In some embodiments, the ratio of the height between the growth chamber 110 and the induction coil may be in the range of 1:2.5 to 1:3.5. In some embodiments, the ratio of the height between the growth chamber 110 and the induction coil may be in the range of 1:2.8 to 1:3.

[0041] In some embodiments, the growth chamber 110 may be provided with at least one layer of plate assembly 111. In some embodiments, the plate assembly 111 may be located in the melt within the growth chamber 110.

[0042] When growing silicon carbide crystals, convection occurs in the melt within the growth chamber 110, and silicon moves upward from the bottom of the growth chamber 110, and then evaporates from the liquid state to the gaseous state and continues to overflow, causing excessive consumption of silicon. In addition, the overflowed silicon vapor may overflow outside the growth chamber 110 and adhere to the heat insulation assembly outside the growth chamber, contaminating the heat insulation assembly and potentially affecting the heat insulation performance of the heat insulation member. Accordingly, the at least one layer of plate assembly 111 provided within the growth chamber changes the convection situation of the melt, reduces the speed of the upward movement of silicon, avoids excessive consumption, and avoids or reduces the amount of silicon vapor overflowing outside the growth chamber, thereby avoiding or reducing the contamination of the heat insulation assembly.

[0043] In some embodiments, the material of the plate assembly 111 may be determined according to the type of crystal to be manufactured. For example, when manufacturing silicon carbide crystals, the material of the plate assembly 111 may be the same as the material of the growth chamber 110 (e.g., graphite). Graphite can provide the carbon required for silicon carbide crystal manufacturing as a carbon source, and can also react with silicon to generate silicon carbide. Accordingly, it can reduce the consumption of the growth chamber 110 and further increase the number of uses of the growth chamber 110.

[0044] In some embodiments, the plate assembly 111 may include through holes. The through holes can function as passages for the melt to convect or move. In some embodiments, in order to play the role of reducing the speed of the upward movement of silicon and meet the requirements of convection or movement, the design of the through holes needs to meet certain conditions. For more explanations, reference can be made to FIGS. 2 and 3, so the description is omitted here.

[0045] In some embodiments, when the heating assembly 120 is an induction heating assembly (as shown in FIG. 1), the plate assembly 111 can also provide, as a heat source, the heat required for crystal production (for example, the thermal energy for melting the raw materials required for crystal growth into a melt, the temperature field required for crystal growth).

[0046] In some embodiments, the plate assembly 111 (for example, the uppermost plate assembly) may be located at a position a predetermined distance below the liquid surface of the melt. In some embodiments, the distance below the liquid surface of the melt where the plate assembly 111 (for example, the uppermost plate assembly) is located affects the passage, route, etc. through which the raw materials of the melt required for crystal growth are transported to the crystal growth surface, and further affects the quality of the growing crystal. Therefore, it is necessary to keep the predetermined distance within a predetermined range.

[0047] In some embodiments, the predetermined distance may be in the range of 10 mm to 50 mm. In some embodiments, the predetermined distance may be in the range of 15 mm to 45 mm. In some embodiments, the predetermined distance may be in the range of 20 mm to 40 mm. In some embodiments, the predetermined distance may be in the range of 25 mm to 35 mm. In some embodiments, the predetermined distance may be in the range of 28 mm to 32 mm.

[0048] In some embodiments, in order to improve the stability of crystal growth, the plate assembly 111 (for example, the lowermost plate assembly) may be located near the midpoint of the height of the melt or the heating assembly (for example, the induction coil). In some embodiments, "near" may refer to within a predetermined distance. In some embodiments, the predetermined distance may include ±50 cm, ±40 cm, ±30 cm, ±20 cm, ±10 cm, ±8 cm, ±6 cm, ±4 cm, ±2 cm, ±1 cm, etc. For example, near the midpoint of the height of the melt may include the range of ±30 cm from 1 / 2 of the height of the melt.

[0049] In some embodiments, the distance between adjacent plate assemblies 111 affects factors such as the temperature field near the crystal growth interface, the supply of raw materials (e.g., carbon, silicon) required for growth, and the path through which the raw materials are transported to the crystal growth interface. Therefore, it is necessary to keep the distance between adjacent plate assemblies 111 within a predetermined range.

[0050] In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 10 mm to 60 mm. In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 15 mm to 55 mm. In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 20 mm to 50 mm. In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 25 mm to 45 mm. In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 30 mm to 40 mm. In some embodiments, the distance between adjacent plate assemblies 111 may be in the range of 34 mm to 36 mm.

[0051] In some embodiments, the crystal manufacturing apparatus 100 may further include a chamber cover 130. In some embodiments, the shape and dimensions of the chamber cover 130 may be compatible with the growth chamber 110. In some embodiments, the chamber cover 130 and the growth chamber 110 may be hermetically connected or removably connected (e.g., engaged connection).

[0052] In some embodiments, the crystal manufacturing apparatus 100 may further include a heat insulation assembly 140 for insulating the growth chamber 110. In some embodiments, the heat insulation assembly 140 may be provided around the outer periphery of the growth chamber 110. In some embodiments, the heat insulation assembly 140 may be provided around the outside of the heating assembly 120.

[0053] In some embodiments, the heat insulation assembly 140 may include an upper heat insulation member 141, a middle heat insulation member 142, a chamber bottom heat insulation member 143, and a lower heat insulation member 144.

[0054] In some embodiments, as shown in FIG. 1, the upper heat insulating member 141 may be located at the upper part of the growth chamber 110. In some embodiments, the middle heat insulating member 142 may be located below the lower part of the growth chamber 110 or below the upper heat insulating member 141. In some embodiments, the chamber bottom heat insulating member 143 may be located at the bottom of the growth chamber 110. In some embodiments, the lower heat insulating member 144 may be located below the middle heat insulating member 142 and the chamber bottom heat insulating member 143. In some embodiments, adjacent heat insulating members (e.g., the upper heat insulating member 141 and the middle heat insulating member 142, the middle heat insulating member 142 and the lower heat insulating member 144, the chamber bottom heat insulating member 143 and the lower heat insulating member 144) may be removably connected (e.g., a fitting connection) to facilitate the removal and replacement of damaged heat insulating members.

[0055] In some embodiments, each heat insulating member (e.g., the upper heat insulating member 141, the middle heat insulating member 142, the chamber bottom heat insulating member 143, and the lower heat insulating member 144) may include a bulk heat insulating material, a granular heat insulating material, a cotton-like heat insulating material, a lamellar heat insulating material, etc. In some embodiments, the material of each heat insulating member may include quartz (silicon oxide), corundum (aluminum oxide), zirconium oxide, carbon fiber, ceramics, etc., or other high-temperature resistant materials (e.g., borides, carbides, nitrides, silicides, phosphorus compounds, and sulfur compounds of rare earth metals, etc.). In some embodiments, the materials of each heat insulating member may be the same or different.

[0056] In some embodiments, the crystal manufacturing apparatus 100 may further include a seed crystal holder 150 for bonding a seed crystal. In some embodiments, the material of the seed crystal holder 150 may include graphite. For the description of the seed crystal holder 150 and the seed crystal, reference may be made to other parts of this specification (e.g., FIG. 6 and its description), so the description is omitted here.

[0057] In some embodiments, the crystal manufacturing apparatus 100 may further include a connection assembly 160 that connects the seed crystal holder 150. In some embodiments, the connection assembly 160 may be a cylinder, a pyramid, or the like. In some embodiments, the connection assembly 160 may be integrally formed or may be formed by connecting a plurality of connection members to each other. In some embodiments, the material of the connection assembly 160 may include, but is not limited to, graphite.

[0058] In some embodiments, the crystal manufacturing apparatus 100 may further include a power assembly (not shown), and the power assembly drives the rotation and / or vertical movement of the connection assembly 160 to drive the rotation and / or vertical movement of the seed crystal holder 150 to grow crystals.

[0059] In some embodiments, the crystal manufacturing apparatus 100 may further include a cover plate 170. In some embodiments, the cover plate 170 may be used to reduce cracks in the crystal. In some embodiments, the cover plate 170 may be located above the upper heat insulating member 141. In some embodiments, the cover plate 170 may be a cylinder, a pyramid, or the like. In some embodiments, the material of the cover plate 170 may be the same as or different from the material of the heat insulating assembly 140.

[0060] In some embodiments, as shown in FIG. 1, the chamber cover 130, the upper heat insulating member 141, and the cover plate 170 are provided with through holes through which the connection assembly 160 and the seed crystal holder 150 pass for rotation and / or vertical movement.

[0061] In some embodiments, the size of the holes in the cover plate 170 affects the volatilization amount of silicon. For example, if the size of the holes is too large, heat will dissipate from the holes, increasing the thermal energy that the heating assembly should provide, further increasing the temperature of the melt, and causing an increase in the volatilization amount of silicon. If the size of the holes in the cover plate 170 is too small, the connection assembly 160 and the seed crystal holder 150 cannot pass through and rotate and / or move up and down, and the crystal cannot grow normally. Therefore, it is necessary to make the diameter of the holes in the cover plate 170 within a predetermined range.

[0062] In some embodiments, the diameter of the holes in the cover plate 170 may be in the range of 20 mm to 150 mm. In some embodiments, the diameter of the holes in the cover plate 170 may be in the range of 40 mm to 120 mm. In some embodiments, the diameter of the holes in the cover plate 170 may be in the range of 50 mm to 100 mm. In some embodiments, the diameter of the holes in the cover plate 170 may be in the range of 70 mm to 80 mm.

[0063] It should be noted that the above description of the crystal manufacturing apparatus 100 is only for illustration and explanation, and does not limit the scope of application of this application. Those skilled in the art can make various modifications and changes to the crystal manufacturing apparatus 100 under the guidance of this application. However, these modifications and changes are still included within the scope of this application.

[0064] FIG. 2 is a schematic diagram of the through holes of an exemplary plate assembly according to some embodiments of this specification. FIG. 3 is a schematic diagram of the through holes of an exemplary plate assembly according to some embodiments of this specification.

[0065] In some embodiments, as shown in FIGS. 2 and 3, the plate assembly 111 may include a through hole 1111. In some embodiments, the through hole 1111 may penetrate the plate assembly 111. In some embodiments, the shape of the through hole 1111 may include regular shapes such as circular, elliptical, polygonal, star-shaped, or irregular shapes. In some embodiments, the shapes of the through holes 1111 of the plate assembly 111 may be the same or different. In some embodiments, the shapes of the through holes 1111 of different plate assemblies 111 may be the same or different.

[0066] In some embodiments, the through holes 1111 of adjacent plate assemblies 111 may be offset from each other. For example, as shown in FIG. 2, the through hole 1111 (shown by the solid line in FIG. 2) of the plate assembly located above and the through hole 1111' (shown by the dashed line in FIG. 2) of the plate assembly located below do not overlap. In some embodiments, being offset from each other may mean not overlapping each other or partially overlapping each other.

[0067] By designing the through holes 1111 of adjacent plate assemblies 111 to be offset from each other, the convection of the melt in the growth chamber 110 can be adjusted, the upward movement speed of the volatile components (e.g., silicon) can be reduced, the evaporation amount of the volatile components (e.g., silicon) on the surface of the melt can be reduced, the silicon carbide particles generated by the reaction between the volatile components (e.g., silicon vapor) and the graphite of the growth chamber 110 can be decreased, and furthermore, the evaporated silicon or the generated silicon carbide particles can be reduced from adhering to the upper heat insulation assembly and contaminating and damaging the heat insulation assembly, the heat insulation performance of the heat insulation assembly can be guaranteed, and furthermore, the normal growth of the crystal can be guaranteed.

[0068] The ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located affects the convection of the melt in the growth chamber 110 and further affects the normal growth of crystals. For example, if the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located is too large, the upward movement speed of silicon cannot be effectively improved, and accordingly, the volatilization of silicon on the surface of the melt cannot be effectively reduced. Also, for example, if the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located is too small, the resistance to the upward movement of the melt increases, and it cannot be guaranteed that the melt moving near the seed crystal is sufficient, which further affects the crystal growth rate. Therefore, in some embodiments, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located needs to meet certain requirements.

[0069] In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 30% to 80%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 35% to 75%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 40% to 70%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 45% to 65%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 50% to 60%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 52% to 58%. In some embodiments, for at least one of the at least one layer of plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 may be in the range of 54% to 56%.

[0070] In some embodiments, for different plate assemblies 111, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located may be the same or different. In some embodiments, in the direction from the bottom of the growth chamber 110 to the top of the growth chamber 110, the ratio of the total opening area of the through holes 1111 to the upper surface area of the plate assembly 111 where the through holes 1111 are located may gradually decrease or increase. For example, as shown in FIG. 2, the ratio of the total opening area of the through holes 1111 (shown by solid lines in FIG. 2) of the plate assembly located above to the upper surface area of the plate assembly may be smaller than the ratio of the total opening area of the through holes 1111’ (shown by dashed lines in FIG. 2) of the plate assembly located below to the upper surface area of the plate assembly.

[0071] In some embodiments, as shown in FIG. 3, the density of the through holes 1111 (for example, the number of through holes 1111 per unit area) may gradually decrease from the center to the edge of the plate assembly 111. In some embodiments, the density of the through holes near the center of the plate assembly 111 may be higher than the density of the through holes near the edge of the plate assembly 111. Accordingly, sufficient melt moves upward from the through holes 1111 near the center of the plate assembly 111 to reach the seed crystal and crystallize to grow the crystal, and by improving the convection situation of the melt, excessive consumption of silicon is improved and crystal manufacturing efficiency is guaranteed.

[0072] It should be noted that in the embodiments of this specification, "near" may refer to within a predetermined distance. In some embodiments, the predetermined distance may include 10 cm, 8 cm, 6 cm, 4 cm, 2 cm, 1 cm, etc. In some embodiments, "near the center" of the plate assembly 111 may refer to the area of the plate assembly with the center of the plate assembly 111 as the center of the circle and the radius as the predetermined distance. In some embodiments, "near the edge" of the plate assembly 111 may refer to the area of the plate assembly at a predetermined distance from the edge of the plate assembly 111.

[0073] If the ratio of the density of through-holes near the center of the plate assembly 111 to the density of through-holes near the edge of the plate assembly 111 is too small, silicon carbide on the inner wall of the growth chamber 110 will experience natural nucleation or an increased natural nucleation rate. If the ratio of the density of through-holes near the center of the plate assembly 111 to the density of through-holes near the edge of the plate assembly 111 is too large, the growth of crystal centers will be too fast, resulting in the formation of a coating and cracks. Therefore, in some embodiments, it is necessary to keep the ratio of the density of through-holes near the center of the plate assembly 111 to the density of through-holes near the edge of the plate assembly 111 within a predetermined range.

[0074] In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 20:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 18:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 16:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 14:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 12:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 10:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 8:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 6:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1:1 to 5:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 1.5:1 to 4.5:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 2:1 to 4:1. In some embodiments, the ratio of the density of the through-holes near the center of the plate assembly 111 to the density of the through-holes near the edge of the plate assembly 111 may be in the range of 2.5:1 to 3.5:1.In some embodiments, the ratio of the density of the through holes near the center of the plate assembly 111 to the density of the through holes near the edge of the plate assembly 111 may be in the range of 2.8:1 to 3.2:1.

[0075] The diameter of the through hole 1111 affects the convection of the melt in the growth chamber 110 and further affects the normal growth of the crystal. For example, if the diameter of the through hole 1111 is too large, the upward movement speed of silicon cannot be effectively improved, and accordingly, the volatilization of silicon on the surface of the melt cannot be effectively reduced. Also, for example, if the diameter of the through hole 1111 is too small, the resistance to the upward movement of the melt increases, and it cannot be guaranteed that there is sufficient melt moving near the seed crystal, which further affects the crystal growth rate. Therefore, in some embodiments, the diameter of the through hole 1111 needs to meet certain requirements.

[0076] In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 10 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 9 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 8 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 7 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 6 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 5 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.1 mm to 5 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 0.5 mm to 4.5 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 1 mm to 4 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 1.5 mm to 3.5 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 2 mm to 3 mm. In some embodiments, the diameter of the through hole 1111 may be in the range of 2.4 mm to 2.6 mm.

[0077] Figure 4 is a schematic configuration diagram of an exemplary chamber cover and a part of an upper heat insulating member according to some embodiments of the present specification.

[0078] As described above, in the crystal manufacturing process, silicon moves upward from the bottom of the growth chamber 110, and then evaporates to become a gaseous state, and continues to overflow in the form of silicon vapor. The silicon vapor overflows outside the chamber cover 130, cools and condenses, and adheres to the surface of the upper heat insulating assembly 141, which may affect its heat insulating performance. Therefore, in some embodiments, as shown in FIG. 4, there may be a gap 131 between the chamber cover 130 and the upper heat insulating member 141 for the silicon vapor formed by volatilization to react with the carbon powder, and the gap 131 may be filled with carbon powder, thereby preventing the silicon vapor from overflowing outside, cooling and condensing, and adhering to the surface of the upper heat insulating assembly 141, or preventing the silicon carbide particles generated by the reaction between the silicon vapor and the growth chamber 110 from adhering to the heat insulating assembly and affecting its heat insulating performance.

[0079] In some embodiments, as shown in FIG. 4, the chamber cover 130 may include a protrusion structure 132. Since the temperature near the protrusion structure 132 is low (lower than the temperature of the melt), some of the silicon vapor condenses on the protrusion structure 132, which can slow down or reduce the overflow of the silicon vapor outside, and reduce the degree of contamination of the upper heat insulating assembly 141. After the crystal growth is completed, a finishing process may be performed on the protrusion structure 132 to facilitate subsequent use.

[0080] Figure 5 is a schematic configuration diagram of an exemplary growth chamber according to some embodiments of the present specification.

[0081] As described above, in the crystal manufacturing process, it is necessary to melt the raw material into a melt (liquid state) and perform crystal growth based on the melt, and the growth chamber 110 needs to provide a carbon source necessary for crystal growth. Therefore, the bottom (or the middle and lower part) of the growth chamber 110 has a high temperature and a high consumption rate.

[0082] Therefore, in some embodiments, the thickness of the side wall of the growth chamber 110 gradually increases along the direction from the top to the bottom of the growth chamber 110 (the direction indicated by the arrow in FIG. 5). Accordingly, it is possible to avoid the bottom from being over-consumed and becoming too thin, and further increase the number of times the growth chamber 110 can be used.

[0083] FIG. 6 is a schematic configuration diagram of an exemplary seed crystal holder and a seed crystal according to some embodiments of the present specification.

[0084] In the crystal manufacturing process, if the seed crystal is too thin, the fire-through phenomenon is likely to occur, which affects the crystal manufacturing effect. And because the seed crystal is too thin, the seed crystal holder inevitably comes into contact with the melt, generating crystals with a crystal form and / or crystal orientation different from that of the seed crystal, and further generating crystal defects. If a seed crystal with a large thickness is directly used, the manufacturing cost of the seed crystal will be significantly increased.

[0085] In some embodiments, the seed crystal 180 may include at least two layers of seed crystals. The mass of the seed crystal for crystal growth (i.e., the lowermost layer of seed crystal that directly contacts the melt) is large, and the mass of the seed crystals in other layers is relatively small. Accordingly, the overall thickness of the seed crystal can be increased while reducing the cost.

[0086] In some embodiments, as shown in FIG. 6, the at least two layers of seed crystals may include a first seed crystal 181 and a second seed crystal 182, and the mass of the first seed crystal 181 may be smaller than the mass of the second seed crystal 182.

[0087] In some embodiments, on the premise that the second seed crystal 182 meets the crystal growth requirements, in order to further reduce the cost of the crystal 180, the thickness of the first seed crystal 181 may be smaller than the thickness of the second seed crystal 182.

[0088] In some embodiments, the bonding method between the seed crystal holder 150 and the first seed crystal 181, and the bonding method between the first seed crystal 181 and the second seed crystal 182 may include, but are not limited to, bonding, optical contact, etc.

[0089] Since there is inevitably a certain gap in the seed crystal holder 150, the gas-phase substances accumulated in the gap or pore region on the back surface of the seed crystal (for example, the bonding surface between the first seed crystal 181 and the seed crystal holder 150) escape, thereby causing defects (for example, planar hexagonal cavity defects) in the finally manufactured crystal.

[0090] Therefore, in some embodiments, as shown in FIG. 6, graphite paper 190 may be filled between the seed crystal holder 150 and the seed crystal 180 (the first seed crystal 181). The graphite paper 190 is soft and has high flatness, which can reduce the porosity of the bonding surface, prevent thermal unevenness on the back surface of the seed crystal, reduce the occurrence of subsequent defects, and improve the bonding strength between the seed crystal holder 150 and the seed crystal 180 (for example, the first seed crystal 181).

[0091] FIG. 7 is a flowchart of an exemplary crystal manufacturing method according to some embodiments of the present specification. In some embodiments, the flow 700 may be executed by one or more assemblies of a crystal manufacturing apparatus (for example, the crystal manufacturing apparatus 100). In some embodiments, the flow 700 may be automatically executed by a control system. For example, the flow 700 may be realized based on control instructions, and the control system controls each assembly based on the control instructions to complete each operation of the flow 700. In some embodiments, the flow 700 may be semi-automatically executed by a control system. For example, one or more operations of the flow 700 may be manually executed by an operator. In some embodiments, when completing the flow 700, one or more additional operations not described may be added, and / or one or more operations described in this specification may be deleted. Also, the order of the operations shown in FIG. 7 is not limiting. As shown in FIG. 7, the flow 700 includes the following steps 710 to 750.

[0092] In step 710, a raw material is placed in the growth chamber.

[0093] In some embodiments, the raw material may refer to the raw materials necessary for crystal growth. For example, when growing silicon carbide crystals, the raw material may include silicon (e.g., silicon powder, silicon wafers, silicon blocks). Also, for example, when growing silicon carbide crystals, the raw material may include silicon and carbon (e.g., carbon powder, carbon blocks, carbon particles). In some embodiments, the raw material includes carbon powder, carbon blocks or carbon particles, and the number of times the growth chamber can be used can be increased. In some embodiments, a flux may be included in the raw material to improve the solubility of carbon in silicon. In some embodiments, the flux may include, but is not limited to, aluminum alloys, silicon-chromium alloys, Li-Si alloys, Ti-Si alloys, Fe-Si alloys, Sc-Si alloys, Co-Si alloys.

[0094] In some embodiments, at least one layer of plate assembly may be provided in the growth chamber. For the related description of the growth chamber (e.g., growth chamber 110) and at least one layer of plate assembly (e.g., plate assembly 111), reference may be made to other parts of this specification (e.g., FIGS. 1-5 and their descriptions), so the description is omitted here.

[0095] In step 720, the growth chamber is heated by a heating assembly so that the raw material melts into a melt.

[0096] For example, when growing silicon carbide crystals, after the raw material melts, a solution containing carbon and silicon is formed to be the liquid raw material for crystal growth.

[0097] For the related description of the heating assembly (e.g., heating assembly 120), reference may be made to other parts of this specification (e.g., FIG. 1 and its description), so the description is omitted here.

[0098] In some embodiments, in order to improve the utilization rate of raw materials, it is necessary to make the ratio of the height of the melt to the height of the growth chamber within a predetermined range. In some embodiments, the ratio of the height of the melt to the height of the growth chamber may be in the range of 1:1 to 1:5. In some embodiments, the ratio of the height of the melt to the height of the growth chamber may be in the range of 1:1.5 to 1:4.5. In some embodiments, the ratio of the height of the melt to the height of the growth chamber may be in the range of 1:2 to 1:4. In some embodiments, the ratio of the height of the melt to the height of the growth chamber may be in the range of 1:2.5 to 1:3.5. In some embodiments, the ratio of the height of the melt to the height of the growth chamber may be in the range of 1:2.8 to 1:3.

[0099] In some embodiments, in order to improve the stability of crystal growth, the liquid level of the melt may be located near the midpoint of the height of the heating assembly (for example, an induction coil). In some embodiments, "near" may refer to within a predetermined distance. In some embodiments, the predetermined distance may include ±50 cm, ±40 cm, ±30 cm, ±20 cm, ±10 cm, ±8 cm, ±6 cm, ±4 cm, ±2 cm, ±1 cm, etc. For example, after the raw material melts into a melt, the liquid level of the melt may be located within the range of ±30 cm of 1 / 2 of the height of the heating assembly (for example, an induction coil).

[0100] In step 730, the seed crystal is coupled to the seed crystal holder.

[0101] In some embodiments, the seed crystal may include at least two layers of seed crystals. In some embodiments, the at least two layers of seed crystals may include a first seed crystal and a second seed crystal. The first seed crystal may be coupled to the seed crystal holder, and the second seed crystal may be coupled to the first seed crystal. In some embodiments, the mass of the first seed crystal may be smaller than the mass of the second seed crystal.

[0102] In some embodiments, before binding the seed crystal to the seed crystal holder, the graphite paper may be bound to the seed crystal holder such that the graphite paper is positioned between the seed crystal holder and the seed crystal. In some embodiments, the seed crystal and / or the graphite paper may be concentric with the seed crystal holder.

[0103] In some embodiments, the thickness of the graphite paper may be in the range of 0.5 mm to 1 mm. In some embodiments, the thickness of the graphite paper may be in the range of 0.6 mm to 0.9 mm. In some embodiments, the thickness of the graphite paper may be in the range of 0.5 mm to 1 mm. In some embodiments, the thickness of the graphite paper may be in the range of 0.7 mm to 0.8 mm.

[0104] In some embodiments, in order to ensure the bonding strength between the graphite paper, the first seed crystal and the second seed crystal, and to ensure the quality of the crystal, the surface flatness of the first seed crystal needs to meet certain conditions. In some embodiments, the surface flatness of the first seed crystal bonded to the graphite paper may be less than 0.01 mm. In some embodiments, the surface flatness of the first seed crystal bonded to the second seed crystal may be in the range of 0.005 mm to 0.008 mm. In some embodiments, the surface flatness of the first seed crystal bonded to the second seed crystal may be in the range of 0.006 mm to 0.007 mm.

[0105] Regarding the related description of the seed crystal (for example, seed crystal 180) and the seed crystal holder (for example, seed crystal holder 150), reference can be made to other parts of this specification (for example, FIG. 6 and its description), so the description is omitted here.

[0106] In step 740, the seed crystal holder with the seed crystal bonded thereto is lowered so that the seed crystal comes into contact with the melt.

[0107] In some embodiments, the power assembly drives the connection assembly to descend, and drives the seed crystal holder to descend, so that the seed crystal contacts the melt.

[0108] In step 750, crystals are produced based on the seed crystal and the melt.

[0109] In some embodiments, the power assembly may drive the rotation and / or vertical movement of the connection assembly to drive the rotation and / or vertical movement of the seed crystal holder, and the melt can condense on the seed crystal and crystallize to grow crystals.

[0110] In the crystal growth process, the melt in the growth chamber convects, the silicon at the lower part moves upward, a part of the silicon is blocked by the plate assembly provided in the growth chamber, and a part of the silicon continues to move upward through the through holes of the plate assembly. Since the through holes of the adjacent plate assemblies are offset from each other, the silicon that continues to move upward is blocked by the upper plate assembly. Repeating in this way, the silicon reaching the upper surface of the melt due to the convection of the melt is significantly reduced, and accordingly, the volatilization of silicon on the upper surface of the melt is reduced, further, the degree of contamination of the heat insulation assembly is reduced, the heat insulation performance of the heat insulation assembly is maintained, and further, the normal growth of the crystal can be guaranteed.

[0111] It should be noted that the above description regarding flow 700 is only for illustration and explanation, and does not limit the scope of application of this application. Those skilled in the art can make various modifications and changes to flow 700 under the guidance of this application. However, these modifications and changes are still included within the scope of this application.

[0112] The beneficial effects according to the embodiments of this specification include, but are not limited to, the following: (1) At least one layer of plate assembly is provided in the growth chamber, and the material of the plate assembly includes graphite, which can provide the raw materials required for the production of silicon carbide crystals as a carbon source. (2) The plate assembly includes through-holes, and by designing the through-holes of adjacent plate assemblies to be offset from each other, the convection of the melt in the growth chamber can be adjusted, the upward movement speed of volatile components (such as silicon) can be reduced, the volatilization amount of volatile components (such as silicon) on the surface of the melt can be reduced, excessive consumption of volatile components can be decreased, silicon carbide particles generated by the reaction between volatile components (such as silicon vapor) and the growth chamber can be reduced, the contamination degree of the heat insulation assembly can be further reduced, the heat insulation performance of the heat insulation assembly can be guaranteed, and the normal growth of crystals can be further guaranteed. (3) By applying a coating or providing a shielding ring in a predetermined upper range of the inner wall of the growth chamber, it is possible to avoid silicon on the surface of the melt from reacting with the carbon on the side wall of the growth chamber to spontaneously nucleate, crystallize, and grow. (4) There is a gap between the chamber cover and the upper heat insulation member, and the gap is filled with carbon powder. The carbon powder reacts with the silicon vapor formed by volatilization to avoid the silicon vapor from overflowing outside the heat insulation assembly, or to avoid silicon carbide particles generated by the reaction between the silicon vapor and the growth chamber from adhering to the heat insulation assembly and affecting its heat insulation performance. (5) Since the chamber cover includes a protrusion structure, some silicon vapor can condense on the protrusion structure, delaying or reducing the overflow of the silicon vapor to the outside, and reducing the contamination degree of the heat insulation assembly. (6) By including at least two layers of seed crystals, the thickness can be increased, the risk of fire-through can be reduced, and the quality of the produced crystals can be further guaranteed. (7) By making the mass of the first seed crystal bonded to the seed crystal holder smaller than the mass of the second seed crystal bonded to the first seed crystal, the cost of the seed crystal can be reduced, and the crystal production cost can be further reduced.Note that the beneficial effects of different embodiments are different. In different embodiments, they may be any one or more combinations of the above, or any other possible beneficial effects.

[0113] Having described the basic concepts above, it is clear to those skilled in the art that the above detailed disclosure is merely exemplary and does not limit this specification. Although not explicitly described in this specification, those skilled in the art can make various changes, improvements, and modifications to this specification. Since these changes, improvements, and modifications are proposed in this specification, they are still within the spirit and scope of the exemplary embodiments of this specification.

[0114] Also, to describe the embodiments of this specification, specific terms are used in this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" mean specific features, structures, or characteristics related to at least one embodiment of this specification. Therefore, it should be emphasized and understood that the two or more mentions of "an embodiment" or "one embodiment" or "one alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. Also, the specific features, structures, or characteristics in one or more embodiments of this specification may be appropriately combined.

[0115] Similarly, in the foregoing description of the embodiments of this specification, for the sake of simplifying the expressions disclosed in this specification and facilitating the understanding of one or more embodiments of the invention, it should be understood that various features may be grouped together in one embodiment, drawing, or its description. However, such a disclosure method does not mean that the features required for the subject matter of this specification are more than the features described in the claims. In fact, the features of an embodiment may be less than all the features of the single embodiment disclosed above.

[0116] In some embodiments, numbers are used to describe the number of components and attributes, and it should be understood that the numbers for describing such embodiments are modified by the modifier "about", "substantially" or "generally" in some examples. Unless otherwise specified, "about", "substantially" or "generally" indicates that the above numbers are allowed a variation of ±20%. Therefore, in some embodiments, the numerical parameters used in the specification and claims are all approximate values that can vary according to the characteristics required for individual embodiments. In some embodiments, for numerical parameters, the specified number of significant digits should be considered and the normal rounding method should be applied. In some embodiments of this specification, the numerical ranges and parameters for determining the range are approximate values, but in specific embodiments, such numbers are set as accurately as possible.

[0117] All patents, patent applications, published patent gazettes, and other materials such as papers, books, specifications, publications, documents, etc. referred to in this specification are incorporated herein by reference in their entirety, except for application process documents that do not match or conflict with the content of this specification, and documents that may have a limiting effect on the broadest scope of the claims of this specification (currently or later related to this specification). In addition, if the explanations, definitions, and / or uses of terms in the attached materials of this specification do not match or conflict with the content described in this specification, the explanations, definitions, and / or uses of terms in this specification shall prevail.

[0118] Finally, it should be understood that the embodiments described in this specification are merely for explaining the principles of the embodiments of this specification. Other variations may also be within the scope of this specification. Therefore, without limitation, by way of example, alternative configurations of the embodiments of this specification may be considered to be in accordance with the teachings of this specification. Therefore, the embodiments of this specification are not limited to the embodiments clearly introduced and described in this specification.

Description of Reference Signs

[0119] 100 Crystal manufacturing apparatus 110 Growth chamber 120 Heating Assembly 111 Plate Assembly 1111 Through-Hole 130 Chamber Cover 131 Gap 132 Protrusion Structure 140 Heat Insulation Assembly 141 Upper Heat Insulation Member 142 Middle Heat Insulation Member 143 Chamber Bottom Heat Insulation Member 144 Lower Heat Insulation Member 150 Seed Crystal Holder 160 Connection Assembly 170 Cover Plate 180 Seed Crystal 181 First Seed Crystal 182 Second Seed Crystal 190 Graphite Paper

Claims

1. A crystal manufacturing apparatus including a growth chamber provided therein with at least one layer of plate assemblies, and a heating assembly for heating the growth chamber.

2. The crystal manufacturing apparatus according to Claim 1, wherein the plate assembly includes through holes.

3. The crystal manufacturing apparatus according to Claim 2, wherein the through holes of adjacent plate assemblies are offset from each other.

4. For at least one of the at least one layer of plate assemblies, a ratio of a total opening area of the through holes to an upper surface area of the plate assembly is within a range of 30% to 80%. The crystal manufacturing apparatus according to Claim 2.

5. The crystal manufacturing apparatus according to Claim 2, wherein a density of the through holes gradually decreases from a center to an edge of the plate assembly.

6. A ratio of a density of through holes near a center of the plate assembly to a density of through holes near an edge of the plate assembly is within a range of 1:1 to 20:

1. The crystal manufacturing apparatus according to Claim 2.

7. The crystal manufacturing apparatus according to Claim 2, wherein a diameter of the through holes is within a range of 0.1 mm to 10 mm.

8. The crystal manufacturing apparatus according to Claim 1, wherein the plate assembly is located in a melt within the growth chamber and is located at a position a predetermined distance below a liquid surface of the melt.

9. The crystal manufacturing apparatus according to Claim 1, wherein a distance between adjacent plate assemblies is within a range of 10 mm to 60 mm.

10. In a predetermined upper range of a side wall of the growth chamber, a coating is applied or a shielding ring is provided. The crystal manufacturing apparatus according to Claim 1.

11. The crystal manufacturing apparatus according to Claim 10, wherein the predetermined upper range is a range of 0 to 2 / 3 along a height direction of the growth chamber.

12. Further including a chamber cover and an upper heat insulating member, and carbon powder is filled in a gap between the chamber cover and the upper heat insulating member. The crystal manufacturing apparatus according to Claim 1.

13. The crystal manufacturing apparatus according to Claim 12, wherein the chamber cover includes a protrusion structure.

14. The crystal manufacturing apparatus according to Claim 1, wherein a thickness of a side wall of the growth chamber gradually increases along a direction from a top to a bottom of the growth chamber.

15. Further including a seed crystal holder for bonding seed crystals including at least two layers of seed crystals. The crystal manufacturing apparatus according to Claim 1.

16. The heating assembly includes an induction coil, the induction coil is disposed around the outer periphery of the growth chamber, and the ratio of the height of the growth chamber to the induction coil is in the range of 1:1 to 1:

5. The crystal manufacturing apparatus according to claim 1.

17. A step of disposing a raw material in a growth chamber provided with at least one layer of plate assembly therein; A step of heating the growth chamber by a heating assembly so that the raw material melts into a melt; A step of bonding a seed crystal to a seed crystal holder; A step of lowering the seed crystal holder to which the seed crystal is bonded so that the seed crystal contacts the melt; A crystal manufacturing method including a step of manufacturing a crystal based on the seed crystal and the melt.

18. The seed crystal includes at least two layers of seed crystals, the at least two layers of seed crystals include a first seed crystal and a second seed crystal, the first seed crystal is bonded to the seed crystal holder, the second seed crystal is bonded to the first seed crystal, and the mass of the first seed crystal is smaller than the mass of the second seed crystal. The crystal manufacturing method according to claim 17.

19. Filling graphite paper between the seed crystal holder and the seed crystal. The crystal manufacturing method according to claim 17.

20. The ratio of the height of the melt to the growth chamber is in the range of 1:1 to 1:

5. The crystal manufacturing method according to claim 17.

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