Crystal growth equipment

Abstract

The embodiment of the invention provides crystal growth equipment. The equipment comprises a furnace body, a crucible and a heating assembly, wherein the furnace body comprises a hearth, and the crucible and the heating assembly are both arranged in the hearth; the heating assembly is used for heating the crucible; the heating assembly comprises a first heating assembly and / or a second heating assembly, and the first heating assembly is used for heating the bottom of the crucible; and the second heating assembly is used for heating the side part of the crucible.

Description

Technical Field

[0001] The present invention relates to the field of crystal growth, and in particular to a crystal growth device. Background Art

[0002] Physical Vapor Transport (PVT) is a method for preparing semiconductor crystals. During the growth of semiconductor crystals, an axial temperature gradient is formed between the material and the seed crystal by controlling the temperature field distribution in the growth chamber (e.g., a crucible). The material decomposes and sublimates into gaseous components under high temperature conditions. The gaseous components are transported to the seed crystal in the low temperature zone under the drive of the axial temperature gradient and deposited on the surface of the seed crystal to form a crystal. Summary of the invention

[0003] One of the embodiments of the present specification provides a crystal growth device, which includes a furnace body, a crucible and a heating component; wherein the furnace body includes a furnace chamber, and the crucible and the heating component are both arranged in the furnace chamber; the heating component heats the crucible.

[0004] In some embodiments, the heating assembly includes a first heating assembly and / or a second heating assembly, wherein the first heating assembly heats the bottom of the crucible; and the second heating assembly heats the side of the crucible.

[0005] In some embodiments, the second heating component includes the second induction coil; the second induction coil is arranged around the side wall of the crucible; the first heating component includes the first induction coil, and the first induction coil is arranged around the bottom wall of the crucible; or the first heating component includes the first resistance heater, and the first heating component is arranged below the bottom wall of the crucible.

[0006] In some embodiments, a graphite ring is disposed at the bottom of the crucible, and the first induction coil at least partially surrounds the outside of the graphite ring; or the first resistance heater is embedded in the bottom wall of the crucible.

[0007] In some embodiments, an annular barrier is disposed between the first induction coil and the second induction coil, and the annular barrier is disposed around the crucible.

[0008] In some embodiments, the heating assembly further includes a third heating assembly, and the third heating assembly heats the top of the crucible.

[0009] In some embodiments, the third heating assembly includes a second resistive heater.

[0010] In some embodiments, the distance between the first resistance heater and the second resistance heater and the crucible is respectively greater than 20 mm; and / or, the first resistance heater and the second resistance heater both include resistance wires, and the minimum spacing distance between the resistance wires is in the range of 10 mm-15 mm.

[0011] In some embodiments, during the crystal growth stage, the ratio of bottom heat to side heat obtained by the material in the crucible is 1-4, and the ratio of side heat to top heat is 1-3; during the annealing stage, the ratio of top heat and side heat obtained by the material in the crucible is in the range of 1.5-5, the bottom heat is provided by the first heating component, the side heat is provided by the second heating component, and the top heat is provided by the third heating component.

[0012] In some embodiments, the second heating assembly further includes a third induction coil, and the third induction coil is sleeved outside the second induction coil.

[0013] In some embodiments, the power of the first induction coil is greater than the power of the second induction coil.

[0014] In some embodiments, the device also includes: a first induction coil moving mechanism, used to drive the second induction coil to move along the axial direction of the crucible, the first induction coil moving mechanism is connected to the second induction coil; a second induction coil moving mechanism, used to drive the third induction coil to move along the axial direction of the crucible, the second induction coil driving mechanism is connected to the third induction coil.

[0015] In some embodiments, the device also includes a fourth induction coil and a fifth induction coil, the fourth induction coil is arranged below the second induction coil in the axial direction of the crucible; the fifth induction coil is sleeved on the outside of the fourth induction coil, and the fifth induction coil is arranged below the third induction coil in the axial direction of the crucible.

[0016] In some embodiments, the device also includes a filtering structure disposed in the furnace, wherein the filtering structure is located above the material in the crucible in the axial direction of the crucible, wherein the filtering structure includes a through hole that penetrates the filtering structure from top to bottom along the axial direction of the crucible.

[0017] In some embodiments, the material of the filter structure includes graphite; or the material of the filter structure includes one or more of tantalum, tungsten, titanium, and corresponding nitrides or carbides.

[0018] In some embodiments, the through holes in the middle portion of the filter structure have a larger hole size and a smaller porosity, and the through holes in the edge portion of the filter structure have a smaller hole size and a larger porosity.

[0019] In some embodiments, the porosity of the filtration structure is in the range of 5% to 40%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0021] Figure 1 is a block diagram of a crystal growth apparatus according to some embodiments of the present specification;

[0022] Figure 2 is a schematic diagram of the structure of a crystal growth device according to some embodiments of this specification;

[0023] Figure 3 is a schematic diagram of the structure of a resistance heater according to some embodiments of this specification;

[0024] Figure 4 is a schematic diagram of the arrangement of the first induction coil according to some embodiments of this specification;

[0025] Figure 5 is a schematic diagram of the arrangement of the first induction coil and the second induction coil according to some embodiments of this specification;

[0026] Fig. 6A is a schematic diagram of the structure of a second heating assembly according to some embodiments of this specification;

[0027] Figure 6B is a schematic diagram of the structure of the second heating assembly and the first induction coil moving mechanism according to some embodiments of this specification;

[0028] Figure 7 It is the axial temperature gradient diagram of the inner cavity of the crucible corresponding to the crucible at different positions;

[0029] Figure 8 It is the axial temperature distribution diagram of the inner cavity of the crucible when the crucible is at different positions;

[0030] Fig. 9 is an axial temperature distribution diagram of the inner cavity of the crucible corresponding to the power of the third induction coil at different powers;

[0031] Fig.10 It is a bar graph of the temperature difference between the seed crystal and the material surface corresponding to the power of the third induction coil at different powers;

[0032] Fig.11A is a schematic diagram of the structure of a second heating assembly according to other embodiments of this specification;

[0033] Fig. 11B is an axial temperature distribution diagram of the inner cavity of the crucible corresponding to the fourth induction coil and the fifth induction coil at different powers;

[0034] Fig. 11C is a bar graph of the temperature difference between the seed crystal and the material surface corresponding to the fourth induction coil and the fifth induction coil at different powers;

[0035] Fig.12 is a schematic diagram of the structure of a crystal growth device according to other embodiments of this specification;

[0036] Fig.13 is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification;

[0037] Fig.14 is a schematic diagram of a filtering structure according to some embodiments of the present specification;

[0038] Explanation of the reference numerals: 100, crystal growth equipment; 110, furnace body; 111, first chamber; 112, second chamber; 113, third chamber; 120, crucible; 130, heating assembly; 121, upper cover; 122, main body; 131, first heating assembly; 1311, first resistance heater; 13111, resistance wire; 1312, first induction coil; 132, second heating assembly; 1321, second induction coil; 1322, third induction coil; 1323, fourth induction coil; 1324, fifth induction coil; 133, graphite ring; 134, annular baffle; 135, third heating assembly; 1351, second resistance heater; 136, third resistance heater; 140, material; 150, filtering structure; 151, through hole; 60, first induction coil moving mechanism; 61, suspension rod; 62, driving member; 200, seed crystal. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0040] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural, unless the context clearly indicates an exception. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment".

[0041] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this specification can be understood according to specific circumstances.

[0042] The words "first", "second" and similar terms used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "an" do not indicate a quantity limitation, but indicate the existence of at least one. In the description of this specification, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0043] Unless otherwise indicated, the words "top", "bottom", "side", "lower" and / or "upper" and the like are for convenience of description only and are not limited to a position or a spatial orientation. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

[0044] Figure 1 FIG. 1 is a block diagram of a crystal growth device according to some embodiments of the present specification. Figure 1 As shown, the crystal growth apparatus 100 includes a furnace body 110 , a crucible 120 , and a heating assembly 130 . The heating assembly 130 heats the crucible 120 .

[0045] The crystal growth apparatus 100 can be used to prepare a crystal. In some embodiments, the crystal growth apparatus 100 can prepare a crystal based on a physical vapor transport (PVT) method. In some embodiments, the crystal can include but is not limited to a silicon carbide crystal, an aluminum nitride crystal, a zinc oxide crystal, or a zinc antimonide crystal.

[0046] The furnace body 110 is a structure for accommodating the crucible 120 and the heating assembly 130. In some embodiments, the furnace body 110 includes a furnace chamber, and the crucible 120 and the heating assembly 130 are disposed in the furnace chamber.

[0047] The crucible 120 is used to provide a place for crystal growth. In some embodiments, the crucible 120 includes an inner cavity and a wall body surrounding the inner cavity, and the material 140 is contained in the inner cavity of the crucible 120. In some embodiments, the material of the crucible 120 may include but is not limited to graphite. In some embodiments, the material of the crucible 120 may include graphite and silicon carbide. In some embodiments, the mass of graphite accounts for 40% to 90%, 45% to 85%, 50% to 80%, 55% to 75%, 60% to 70%, 64 to 66% of the mass of the crucible 120. In some embodiments, the shape of the crucible 120 may include but is not limited to regular shapes such as cylinders and cuboids or irregular shapes. For ease of explanation, the crucible 120 is described as a cylinder. The crucible 120 has an axial direction extending along its central axis. In the axial direction, the crucible 120 has two ends, one end is the top, the end opposite to the top is the bottom, and the part between the top and the bottom is the side.

[0048] In some embodiments, the crucible 120 may include an upper cover 121 and a main body 122. The main body 122 may include the wall body surrounding the inner cavity as described above, and the inner cavity is formed in the main body 122. The upper cover 121 may be located on the top of the main body 122 to close the top opening of the main body 122.

[0049] In some embodiments, the shape of the main body 122 may include but is not limited to a cylinder, a cuboid, or a cube. In some embodiments, the shape of the upper cover 121 may include but is not limited to a disc, a rectangular disc, or a square disc. In some embodiments, the shape of the upper cover 121 may match that of the main body 122. In some embodiments, the shape of the main body 122 may be cylindrical, including a bottom and a side wall of the cylinder, the bottom of the cylinder may form the bottom wall of the crucible, and the side wall of the cylinder may form the side wall of the crucible. In some embodiments, the shape of the main body 122 may be a cylindrical barrel, and the shape of the upper cover 121 may be a disc. In some embodiments, the shape of the main body 122 may be a cuboid barrel, and the shape of the upper cover 121 may be a rectangular disc or a square disc. In some embodiments, the materials of the upper cover 121 and the main body 122 may be the same or different.

[0050] In some embodiments, a seed crystal 200 is provided above the crucible 120, and a material 140 is provided inside the crucible 120. In some embodiments, the seed crystal 200 can be bonded to the upper cover 121. The seed crystal 200 can be a small crystal having the same crystal orientation as the crystal to be grown, which can be used as a seed for growing a crystal. In some embodiments, the seed crystal 200 can be made based on a physical vapor transport (PVT) method, a chemical vapor deposition (CVD) method, or a pulling method. In some embodiments, the size of the seed crystal 200 can be 4 inches, 8 inches, etc. The type of the seed crystal 200 can be a 4H-SiC seed crystal, a 6H-SiC seed crystal, etc.

[0051] Material 140 is a raw material for growing a crystal. The raw material may include a material for supplying a seed crystal to grow into a crystal. In some embodiments, the component of the raw material of the silicon carbide crystal may include SiC. In some embodiments, the component of the raw material of the aluminum nitride crystal may include AlN. In some embodiments, the raw material may be a powder, granular and / or bulk material.

[0052] like Figure 2 As shown, the seed crystal 200 can be bonded to the lower side of the upper cover 121 , and the material 140 can be placed in the main body 122 . Figure 2 The middle dotted line a shows the lower surface of the seed crystal 200. Figure 2 The dotted line b shows the upper surface of the material 140, and the space between the dotted line a and the dotted line b is the space for crystal growth.

[0053] In the crystal growth stage, the material 140 in the crucible 120 is heated and sublimated into gas phase components, which are transported to the seed crystal 200 in the crystallization region and then crystallized on the surface of the seed crystal 200 to generate crystals.

[0054] In some embodiments, at least one temperature measuring component ( Figure 1 (not shown). The temperature measurement component is used to measure the temperature inside the crucible 120. As an example only, the temperature measurement component may include a temperature sensor, an infrared thermometer, etc.

[0055] In some embodiments, at least one temperature measuring assembly can be used to measure the temperature inside the crucible 120. For example, at least one temperature measuring assembly can be used to measure the temperature of at least one location such as the lower surface of the seed crystal 200, the crystal growth surface, the upper surface of the material 140, and the space where the crystal grows.

[0056] The heating assembly 130 is used to heat the crucible 120 to provide a temperature field required for crystal growth. In some embodiments, when the heating assembly 130 heats the crucible 120, a temperature field can be formed inside the crucible 120 (i.e., in the inner cavity) to heat the material 140, so that the material 140 sublimates and grows a crystal on the growth surface of the seed crystal 200.

[0057] In some embodiments, the heating component 130 may include, but is not limited to, an electromagnetic induction heater, a resistance heater, and the like. In some embodiments, the electromagnetic induction heater may include an induction coil. Under the action of alternating current of different frequencies, the induction coil may generate eddy currents on the outer wall of the crucible 120. Under the action of the eddy currents, the electrical energy generated on the outer wall of the crucible 120 may be converted into thermal energy, and the thermal energy is conducted from the wall of the crucible 120 to the inside of the crucible 120 to form a temperature field inside the crucible 120. In some embodiments, the resistance heater may include a resistance wire, and the material of the resistance wire may include, but is not limited to, at least one of graphite, tungsten, platinum, molybdenum, tantalum, or iridium. Accordingly, the resistance heater may include, but is not limited to, at least one of a graphite resistance heater, a tungsten resistance heater, a platinum resistance heater, a molybdenum resistance heater, a tantalum resistance heater, or an iridium resistance heater.

[0058] In some embodiments, when the heating component 130 is an electromagnetic induction heater, the electromagnetic induction heater can be arranged around the crucible 120. In some embodiments, the electromagnetic induction heater can be disposed in an outer region of the crucible 120 at a certain distance from the outer wall of the crucible 120. In some embodiments, when the heating component 130 is a resistance heater, the resistance heater can be disposed on the crucible wall (such as the bottom wall or the side wall) of the crucible 120. For example, embedded in the crucible wall of the crucible 120, or connected to the outer surface of the crucible wall of the crucible 120. In other embodiments, when the heating component 130 is a resistance heater, the resistance heater can be disposed at a certain distance from the crucible wall (such as the bottom wall or the side wall) of the crucible 120.

[0059] The heating of the crucible 120 by the heating assembly 130 will form a temperature gradient in the crucible 120 (in the inner cavity). The temperature gradient may include an axial temperature gradient and a radial temperature gradient. The axial temperature gradient refers to the temperature difference per unit distance in the direction of the central axis of the inner cavity of the crucible 120. During the crystal growth process, the temperature decreases from the bottom of the inner cavity to the top in the direction of the central axis of the inner cavity to form an axial temperature gradient, and such an axial temperature gradient can drive the gas phase components of the sublimated material 140 to be transferred to the crystal growth surface. The radial temperature gradient refers to the temperature difference per unit distance in the direction from the inner wall of the crucible 120 to the central axis of the crucible 120 on a horizontal cross section at the same height of the inner cavity. During the crystal growth process, since the heating assembly 130 generally heats the crucible 120 from the outside of the crucible 120, a radial temperature gradient with decreasing temperature will be presented in the direction from the inner wall of the crucible 120 to the central axis of the crucible 120.

[0060] In some embodiments, the heating assembly 130 may be disposed at the bottom of the crucible 120 (hereinafter referred to as the bottom). At this time, heat energy is conducted from the bottom region (the inner region near the bottom) inside the crucible 120 to the top region (the inner region near the top) inside the crucible 120. At this time, the bottom region inside the crucible 120 may be a relatively high temperature region, and the top region may be a relatively low temperature region, so that the axial temperature gradient inside the crucible 120 decreases monotonically from bottom to top. In some embodiments, the heating assembly 130 may be disposed on the side of the outside of the crucible 120 (hereinafter referred to as the side). At this time, heat energy is conducted from the outer peripheral region (the region near the side of the crucible 120) inside the crucible 120 to the central region (the region near the central axis of the crucible 120) inside the crucible 120 via the wall of the crucible 120. At this time, the outer peripheral region inside the crucible 120 may be a relatively high temperature region, and the central region may be a relatively low temperature region. The temperature of the outer peripheral region of the crucible 120 is higher than the temperature of the central region of the crucible 120, so that there is a radial temperature gradient inside the crucible 120. In some embodiments, the heating assembly 130 may be disposed at the top of the outside of the crucible 120 (hereinafter referred to as the top). At this time, similar to the heating assembly 130 being disposed at the bottom of the crucible 120, the heating assembly 130 being disposed at the top of the crucible 120 makes the axial temperature gradient inside the crucible 120 monotonically decrease from top to bottom. It should be noted that the description of the axial temperature gradient and radial temperature gradient inside the crucible 120 is for the temperature gradient when the heating assembly 130 is disposed only at the corresponding position (such as the heating assembly 130 is disposed only at the bottom of the crucible 120, the heating assembly 130 is disposed only at the side of the crucible 120, or the heating assembly 130 is disposed only at the top of the crucible 120). It can be understood that the heating assembly 130 can also be disposed at multiple positions (such as the side and bottom of the crucible 120), which will make the temperature gradient inside the crucible 120 present a more complicated situation. For example, the heating component 130 can be arranged at the bottom and the top of the crucible 120. The crucible 120 may have higher temperatures at the top and the bottom, while the temperature in the middle area between the top and the bottom is lower. It should be noted that the heating component 130 arranged at the bottom of the crucible 120 can be understood as the heating component 130 mainly heats the bottom of the crucible 120 at this time, the heating component 130 arranged at the side of the crucible 120 can be understood as the heating component 130 mainly heats the side of the crucible 120 at this time; the heating component 130 arranged at the top of the crucible 120 can be understood as the heating component 130 mainly heats the top of the crucible 120 at this time.

[0061] In some embodiments, by adjusting the location of the heating assembly 130, the temperature distribution inside the crucible 120 can be adjusted to promote the growth of crystals in the crucible 120 and ensure the quality of the crystals. In some embodiments, the heating assembly 130 can be arranged at the bottom and side of the crucible 120. In some embodiments, the heating assembly 130 can be arranged at the bottom and top of the crucible 120. In some embodiments, the heating assembly 130 can be arranged at the side and top of the crucible 120. In some embodiments, the heating assembly 130 can be arranged at the bottom, side and top of the crucible 120. Figure 2-Figure 13 The configuration of the crystal growth apparatus 100 and the heating assembly 130 thereof will be further described.

[0062] The following will take the preparation of silicon carbide single crystal as an example to describe the method of preparing a crystal by using the crystal growth device 100. The method may include the following steps:

[0063] Step 1: After the seed crystal 200 and the material 140 are placed in the crucible 120, the crucible is subjected to at least one of the following treatments: vacuuming, leak detection, pressure maintenance, and furnace cleaning.

[0064] Step 1 can be viewed as an operation that is performed in the preparatory stage of the crystal growth process.

[0065] In some embodiments, the seed crystal 200 can be bonded to the inner side of the upper cover 121, and the material 140 can be placed in the main body 122, and the upper cover 121 bonded with the seed crystal can be covered on the top of the main body 122. The seed crystal 200 can be bonded to the inner side of the upper cover 121 by an adhesive. The adhesive can include but is not limited to epoxy resin glue, AB glue, phenolic resin glue or sugar glue. Preferably, the adhesive can be sucrose with a purity of 99.9%. In the process of bonding and fixing the seed crystal, due to uneven application of the adhesive, poor processing accuracy of the inner side of the upper cover, etc., bubbles or gaps may be generated between the back of the seed crystal and the inner side of the upper cover 121, thereby causing the generated crystal to contain defects. Therefore, when the seed crystal is placed in the center of the inner side of the upper cover 121, it is necessary to avoid the generation of bubbles or gaps. In some embodiments, before the seed crystal is bonded to the inner side of the upper cover, the seed crystal can also be cleaned to remove contaminants on the surface of the seed crystal. In some embodiments, the seed crystal can be cleaned with deionized water, an organic solvent, etc.

[0066] In some embodiments, the material 140 (e.g., silicon carbide powder or block) may be placed in the body 122, and the distance between the upper surface of the material 140 and the lower surface of the seed crystal 200 is 30 mm to 50 mm, 35 mm to 50 mm, 40 mm to 50 mm, 45 mm to 50 mm, 30 mm to 45 mm, 35 mm to 45 mm, 35 mm to 40 mm, 30 mm to 40 mm, 35 mm to 40 mm, 30 mm to 35 mm, 40 mm to 45 mm, etc. In some embodiments, the distance between the upper surface of the material 140 and the lower surface of the seed crystal 200 may be 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, etc. In some embodiments, the surface of the material 140 placed in the body 122 needs to be kept flat.

[0067] After the material 140 is placed in the main body 122 , the upper cover 121 bonded with the seed crystal can be covered on the top of the main body 122 to form a closed space to facilitate the growth of the crystal.

[0068] In some embodiments, the loaded and covered crucible 120 can be placed in a temperature field for sealing, vacuuming and leak detection, and then step 2 is performed. For example, the pressure in the crucible 120 can reach 10-5Pa by vacuuming. The vacuuming time can be 3h to 5h. After vacuuming, leak detection and pressure maintenance for 1h to 2h are required. When the leakage rate does not exceed 1Pa within 1h, step 2 can be started.

[0069] Step 2: The pressure of the inner cavity of the crucible 120 is adjusted by controlling the amount of gas introduced into the crucible 120 , and the temperature of the inner cavity of the crucible 120 is adjusted by the heating assembly 130 to perform crystal growth.

[0070] In some embodiments, after the operation of the preparatory stage (such as step 1) is completed, a confined space is formed in the crucible 120, and the operation of step 2 can be started at this time. Step 2 can be regarded as the operation required to be performed during the crystal growth process. The process of crystal growth may include a preheating stage, a crystal growth stage, and an annealing stage. The preheating stage refers to the stage in which the crucible 120 is heated under high pressure so that the temperature in the crucible 120 reaches the temperature at which the material can be stably sublimated. During the preheating stage, the pressure in the crucible 120 is relatively high (such as maintained at 40Kpa-80Kpa). The temperature in the crucible 120 rises (continuously or periodically). The crystal growth stage refers to the stage in which the material sublimates and then the continuous growth of the crystal is achieved on the seed crystal 200. During the crystal growth stage, the pressure in the crucible 120 will be significantly reduced compared to the preheating stage (such as maintained at 1Kpa-1.2Kpa), and the temperature in the crucible 120 may fluctuate slightly (such as increasing by 100°C-300°C), but the temperature in the crucible 120 is generally maintained within a relatively stable temperature range (such as above 2000°C, see the relevant description of the temperature during the crystal growth stage below). The annealing stage refers to the stage where the crystal almost stops growing, the pressure in the crucible 120 increases (such as increasing to 40Kpa-80Kpa again), but the temperature decreases (continuously decreases or decreases in stages). During the annealing stage, the heating component 130 can still heat the crucible 120, thereby controlling the cooling rate of the annealing stage (such as controlling it at 1°C / min to 3°C / min). In some embodiments, the changes in pressure and / or temperature in the crucible 12 can be used as nodes to distinguish between the various stages. For example, when the pressure in the crucible 120 starts to drop rapidly from the high pressure in the preheating stage (e.g., the pressure drop rate is greater than 20 KPa / h), the crystal growth stage begins. When the pressure in the crucible 120 starts to rise rapidly from the pressure in the crystal growth stage (e.g., the pressure increase rate is greater than 20 KPa / h), combined with the temperature drop, the annealing stage begins.

[0071] In some embodiments, during the preheating stage, an inert gas (e.g., argon) may be introduced into the crucible 120, and the pressure may be controlled to be maintained at 400 Pa to 800 Pa. In some embodiments, an inert gas (e.g., argon) may be introduced into the crucible 120, and the pressure may be controlled to be maintained at 450 Pa to 800 Pa, 500 Pa to 800 Pa, 550 Pa to 800 Pa, 600 Pa to 800 Pa, 650 Pa to 800 Pa, 700 Pa to 800 Pa, 750 Pa to 800 Pa, 400 Pa to 750 Pa, 450 Pa to 750 Pa, 500 Pa to 750 Pa, 550 Pa to 750 Pa, 600 Pa to 750 Pa, 650 Pa to 750 Pa, 700 Pa to 750 Pa, 400 Pa to 700 Pa, 450 Pa to 70 ...00 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 500 Pa to 700 Pa, 5 The pressure range is one of the following: 1. The pressure at which the pressure reaches 500Pa or 500Pa, and 2. The pressure at which the pressure reaches 500Pa or 500Pa is within the range of 1. The pressure at which the pressure reaches 500Pa or 500Pa is within the range of 1. The pressure at which the pressure reaches 500Pa or 500Pa is within the range of 1. The pressure at which the pressure reaches 500Pa or 500Pa is within the range of 1. In some embodiments, an inert gas (e.g., argon) may be introduced into the crucible to control the pressure to be maintained at one of 450Pa, 500Pa, 550Pa, 600Pa, 650Pa, 700Pa, 750Pa, 800Pa, etc.

[0072] In some embodiments, during the crystal growth stage, the temperature range of the crucible 120 is maintained at 2100° C. to 2400° C. when the material 140 sublimates. In some embodiments, during the crystal growth stage, the temperature range of the crucible 120 is maintained at 2150° C. to 2400° C., 2200° C. to 2400° C., 2250° C. to 2400° C., 2300° C. to 2400° C., 2350° C. to 2400° C., 2100° C. to 2350° C., 2150° C. to 2350° C., 2200° C. to 2350° C., 2250° C. to 2350° C. ℃, 2300℃~2350℃, 2100℃~2300℃, 2150℃~2300℃, 2200℃~2300℃, 2250℃~2300℃, 2100℃~2250℃, 2150℃~2250℃, 2200℃~2250℃, 2100℃~2200℃, 2150℃~2200℃, 2100℃~2150℃, etc. In some embodiments, during the crystal growth stage, the temperature of the crucible 120 is maintained at one of the temperature values ​​of 2150℃, 2200℃, 2250℃, 2300℃, 2350℃, 2400℃, etc. when the material 140 is sublimated.

[0073] In some embodiments, the material 140 is sublimated in both the preheating stage and the crystal growth stage, and the duration of the sublimation process of the material 140 can be 40 hours to 60 hours in total. In some embodiments, the duration of the sublimation process of the material 140 can be one of 40 hours to 55 hours, 40 hours to 50 hours, 40 hours to 45 hours, 45 hours to 60 hours, 45 hours to 55 hours, 45 hours to 50 hours, 50 hours to 60 hours, 50 hours to 55 hours, 55 hours to 60 hours, etc.

[0074] In some embodiments, after the crystal growth is completed, the annealing stage is entered, at which time a protective gas (eg, argon gas, etc.) may be filled to adjust the pressure to 40 KPa to 80 KPa, and the temperature may be lowered at a rate of 1° C. / min to 3° C. / min.

[0075] The above preparation process is only used as an example, and the process parameters involved may be different in different embodiments, and the order of the above steps is not unique. The order of the steps may be adjusted in different embodiments, or even one or more steps may be omitted. The above examples should not be understood as limiting the scope of protection of this application.

[0076] In some embodiments, the crystal growth device may include a temperature control system, which is used to control the temperature control related parameters of the heating assembly 130, thereby controlling the temperature and temperature gradient in the crucible 120. In some embodiments, the temperature control system can make the radial temperature gradient in the crucible not exceed the preset radial temperature gradient threshold value during crystal growth. In some embodiments, the temperature control system can make the axial temperature gradient in the crucible not exceed the preset axial temperature gradient threshold value during crystal growth. In some embodiments, a preset radial temperature gradient threshold value and / or an axial temperature gradient threshold value can be pre-set. In some embodiments, the preset radial temperature gradient threshold value and / or the axial temperature gradient threshold value can be determined according to preset conditions. In some embodiments, the preset conditions may include, but are not limited to, the size, shape and material of the crucible, the size of the seed crystal, and the type and size of the crystal to be grown.

[0077] The crystal is grown by physical vapor transport (PVT method). During the crystal growth stage, the temperature field distribution in the inner cavity of the crucible 120 can be controlled to form an axial temperature gradient between the material in the crucible 120 and the seed crystal. The material is sublimated into a gas phase component under high temperature conditions, and the gas phase component is transported to the seed crystal under the drive of the axial temperature gradient. Since the temperature at the location of the seed crystal is relatively low, the gas phase component can generate crystals on the surface of the seed crystal. In some embodiments, the crystal may include but is not limited to silicon carbide crystals, aluminum nitride crystals, zinc oxide crystals, or zinc antimonide crystals.

[0078] In some embodiments, the heating assembly 130 may include a first heating assembly 131, and the first heating assembly 131 is mainly used to heat the bottom of the crucible 120. The first heating assembly 131 may be arranged near the bottom of the crucible 120. If only the first heating assembly 131 is arranged, the axial temperature gradient in the crucible 120 may be difficult to control. If the main heating part of the heating assembly 130 is at the bottom of the crucible 120, when the heating temperature of the first heating assembly 131 is high, the axial temperature gradient in the crucible 120 may be too large, resulting in crystal growth defects and reducing the quality and yield of the crystal. Specifically, due to the excessive axial temperature gradient in the inner cavity, the mass transfer is too fast, resulting in the deposition rate of the gas phase component on the lower surface of the seed crystal being too fast, resulting in the formation of large stress on the crystal growth surface, and easily forming defects such as inclusions, which in turn leads to other dislocation defects and affects the crystal quality. When the heating temperature of the first heating assembly 131 is low, the overall temperature in the crucible 120 may be too low or the axial temperature gradient may be too small, which may lead to insufficient driving force, and the deposition speed of the gas phase components on the lower surface of the seed crystal may be too slow, which cannot meet the requirements of the physical vapor transport method for mass transfer. If the axial temperature gradient is unstable, the gas phase components are unevenly distributed in the axial direction, resulting in poor quality of the grown crystal.

[0079] In some embodiments, the heating assembly 130 may include a second heating assembly 132, which is mainly used to heat the side of the crucible 120. The second heating assembly 132 may be arranged near the side of the crucible 120 or around the side of the crucible 120. If only the second heating assembly 132 is arranged, the axial temperature gradient and the radial temperature gradient in the crucible 120 may be difficult to control. If the main heating part of the heating assembly 130 is on the side of the crucible 120, when the heating temperature of the first heating assembly 131 is high, the temperature of the gas phase component after the sublimation of the material may be significantly different in the radial direction of the crucible 120, and the large radial temperature gradient may cause crystal growth defects and reduce the quality and yield of the crystal. In addition, due to the large radial temperature gradient of the crucible 120, the concentration of the gas phase component after the sublimation of the material is unevenly distributed along the radial direction, and the gas phase transmission path is obliquely transmitted from the edge to the center. This transmission method will cause differences in gas phase concentration at the crystal growth interface, resulting in non-planar crystal growth, high internal stress in the crystal, and easy generation of defects such as dislocation and cracking, which directly limits the improvement of crystal quality. When the heating temperature of the first heating component 131 is low, the axial temperature gradient in the crucible 120 may be too small, which may also lead to insufficient driving force, and the deposition speed of the gas phase components on the lower surface of the seed crystal is too slow, which cannot meet the requirements of the physical vapor transport method for mass transfer.

[0080] The crystal growth device provided in some embodiments of the present specification affects the temperature distribution or temperature gradient in the crucible 120 through the specific setting of the heating component 130, so that the temperature gradient in the crucible 120 can meet the requirements of physical vapor transport for temperature-related parameters such as radial temperature gradient and axial temperature gradient of crystal growth, so as to ensure the growth quality of the crystal.

[0081] Figure 2 Schematic diagram of the structure of the crystal growth equipment shown in some embodiments of this specification. Figure 2As shown, the heating assembly 130 includes a first heating assembly 131 and a second heating assembly 132. The first heating assembly 131 heats the bottom of the crucible 120, and the second heating assembly 132 heats the side of the crucible 120. The first heating assembly 131 heating the bottom of the crucible 120 can be understood as the first heating assembly 131 is mainly used to heat the bottom of the crucible 120, that is, the heat provided by the first heating assembly 131 to the bottom is higher than the heat provided by the first heating assembly 131 to other parts of the crucible (such as the side and the top). In addition, the bottom of the crucible 120 may include the bottom wall of the crucible 120 and the area of ​​the side wall of the crucible 120 close to the bottom wall. For example, the side wall of the crucible 120 is equally divided into three areas of the upper part, the middle part, and the lower part along the axial length of the crucible 120, and the area of ​​the side wall of the crucible 120 close to the bottom wall can be the lower area of ​​the side wall. The second heating component 132 heats the side of the crucible 120, which can be understood as the second heating component 132 is mainly used to heat the side of the crucible 120, that is, the heat provided by the second heating component 132 to the side is higher than the heat provided by the second heating component 132 to other parts of the crucible (such as the bottom and the top). The side of the crucible 120 may refer to the side wall of the crucible 120.

[0082] In this embodiment, the heating assembly 130 includes both the first heating assembly 131 and the second heating assembly 132, so that the bottom and the side of the crucible 120 can be heated in a targeted manner, and the bottom heating and the side heating of the crucible 120 can be controlled separately, which is conducive to the regulation of the temperature gradient (including the axial temperature gradient and the radial temperature gradient) in the crucible 120. By separately regulating the heating power, heating time and other parameters of the first heating assembly 131 and the second heating assembly 132, the bottom temperature and the side temperature can be adjusted more flexibly to control and adjust the temperature distribution in the crucible 120. Specifically, since the first heating assembly 131 mainly heats the bottom of the crucible 120, it can provide a larger axial temperature gradient, and the heating area of ​​the second heating assembly 132 can cover a longer area range in the axial direction of the crucible 120, which is conducive to ensuring the overall temperature in the crucible 120, so that the heating temperature of the first heating assembly 131 does not need to be set too high, thereby avoiding the situation where the axial temperature gradient in the inner cavity is too large. Furthermore, due to the existence of the first heating component 131, the heating temperature of the second heating component 132 does not need to be set too high, thereby avoiding the situation where the radial temperature gradient in the inner cavity is too large.

[0083] In some embodiments, the first heating assembly 131 includes a first resistance heater 1311, and heating is achieved by resistive heating. In some embodiments, the first resistance heater 1311 can be arranged along a surface parallel to the bottom wall of the crucible 120 (the wall near the bottom of the crucible), and can be spaced apart from the bottom wall of the crucible 120. In some embodiments, the projection coverage area of ​​the first resistance heater 1311 along the axial direction of the crucible 120 can be greater than or equal to the projection coverage area of ​​the inner cavity of the crucible 120 along the axial direction, so that the heat radiation range of the first resistance heater 1311 can cover the bottom of the crucible 120, thereby uniformly heating the material. Among them, the projection coverage area refers to the area of ​​the area covered by the projection. In some embodiments, in order to avoid the phenomenon of sparking during resistance heating, the distance between the first resistance heater 1311 and the bottom wall of the crucible 120 along the axial direction can be greater than 20 mm (for example, 25 mm or 30 mm).

[0084] Figure 3 is a schematic diagram of the structure of the resistance heater according to some embodiments of this specification. In some embodiments, Figure 3 As shown, the first resistance heater 1311 includes a resistance wire 13111, and the resistance wire 13111 can be arranged in one or more distribution modes such as serpentine distribution, coil distribution, row distribution or column distribution. In some embodiments, to avoid the phenomenon of resistive heating ignition, the minimum spacing distance l between the resistance wires 13111 is in the range of 10mm-15mm (for example, 11mm-14mm or 12mm-13mm). It should be noted that the minimum spacing distance l between the resistance wires 13111 can be understood as the minimum value of the spacing distance between the spaced resistance wires 13111 at each position and each angle. Taking the resistance wire 13111 distributed in a row as an example, the minimum spacing distance can be the row spacing.

[0085] In some embodiments, the first resistance heater 1311 may be embedded in the bottom wall of the crucible 120. For example, a groove is provided on the bottom wall of the crucible 120, and the first resistance heater 1311 is installed in the groove accordingly. In this case, there may be a gap between the first resistance heater 1311 and the bottom wall of the crucible 120 to avoid sparking. The first resistance heater 1311 directly transfers heat to the inside of the crucible 120 through the bottom wall of the crucible 120, thereby improving the heat transfer efficiency.

[0086] Figure 4 is a schematic diagram of the arrangement of the first induction coil according to some embodiments of this specification. Figure 4As shown, the first heating assembly 131 includes a first induction coil 1312, and the first induction coil 1312 heats the bottom of the crucible 120 by electromagnetic induction. The first induction coil 1312 is sleeved outside the crucible 120 and is arranged around the bottom wall of the crucible 120. In some embodiments, the bottom end of the first induction coil 1312 in the axial direction is lower than the bottom of the crucible 120 in the axial direction. In some embodiments, the central axis of the first induction coil 1312 coincides with the central axis of the crucible 120, so that the crucible 120 is heated evenly. In some embodiments, the midpoint of the axial length of the first induction coil 1312 can be located on the plane where the bottom wall of the crucible 120 is located, or the midpoint of the axial length of the first induction coil 1312 is located below the plane where the bottom wall of the crucible 120 is located.

[0087] In some embodiments, in order to make the first induction coil 1312 have a better heating effect on the bottom of the crucible 120, a graphite ring 133 is provided at the bottom of the crucible 120. The graphite ring 133 is a ring structure, and the shape of the cross section of the graphite ring 133 perpendicular to the axis of the crucible 120 can match the shape of the main body 122 of the crucible 120. For example, when the main body 122 is a cylindrical barrel, the graphite ring 133 is a circular ring structure. In some embodiments, the central axis of the graphite ring 133 can coincide with the central axis of the crucible 120. In some embodiments, the side of the graphite ring 133 close to the crucible 120 can be connected to the bottom wall of the crucible 120. In some embodiments, the outer diameter of the graphite ring 133 can be smaller than the diameter of the bottom of the crucible. In some embodiments, in order to ensure a higher heat generation efficiency and heat transfer efficiency, the outer diameter of the graphite ring 133 is equal to the diameter of the bottom of the crucible 120. In some embodiments, in the axial direction, the height dimension of the graphite ring 133 is 1 / 4-1 / 2 (e.g., 1 / 3) of the height dimension of the crucible 120. During the growth of the crystal, the heat energy concentration area of ​​the first induction coil 1312 is adjusted to the graphite ring 133, and the graphite ring 133 conducts the heat energy to the bottom of the crucible 120. At this time, the heat obtained by the bottom of the crucible 120 includes the heat conducted by the graphite ring 133 and the heat of the induction heating of the first induction coil 1312, so as to achieve a better effect of heating the bottom of the crucible 120 by electromagnetic induction.

[0088] In some embodiments, see Figure 2In order to better heat the side of the crucible 120, the second heating assembly 132 includes a second induction coil 1321, which is sleeved on the side of the crucible 120 and arranged around the crucible 120, so as to achieve relatively uniform heating of the side of the crucible 120 by electromagnetic induction. In some embodiments, the bottom end of the second induction coil 1321 in the axial direction is lower than the bottom wall of the crucible 120, or the bottom end of the second induction coil 1321 in the axial direction is located on the plane where the bottom wall of the crucible 120 is located. In some embodiments, the top end of the second induction coil 1321 in the axial direction is higher than the top end of the crucible 120 (such as the upper cover of the crucible 120), or the top end of the second induction coil 1321 in the axial direction is flush with the top end of the crucible 120 (such as the top end of the second induction coil 1321 in the axial direction is located on the plane where the upper cover of the crucible 120 is located). By positioning the top and bottom of the second induction coil 1321 relative to the top and bottom of the crucible 120, the heat energy of the second induction coil 1321 can cover the entire side of the crucible 120. In some embodiments, the central axis of the second induction coil 1321 coincides with the central axis of the crucible 120, so that the heat received by the entire side of the crucible 120 is uniform.

[0089] Figure 2 The embodiment shown is that the first heating component 131 includes a first resistance heater 1311 and the second heating component 132 includes a second induction coil 1321. By heating the bottom of the crucible 120 by the first resistance heater 1311, the heating efficiency can be improved, and a more ideal axial temperature gradient can be formed in the inner cavity. Figure 5 shown.

[0090] Figure 5 is a schematic diagram of the arrangement of the first induction coil and the second induction coil according to some embodiments of this specification. Figure 5 As shown, the first induction coil 1312 and the second induction coil 1321 are both arranged around the side of the crucible 120, and the first induction coil 1312 is located at the lower part of the second induction coil 1321 in the axial direction of the crucible 120. The first induction coil 1312 heats the bottom and the lower part of the side of the crucible 120, and the second induction coil 1321 heats the upper part of the side of the crucible 120. Arranging multiple induction coils to heat the side of the crucible 120 in different areas can well regulate the temperature difference in the crystal plane and the material 140, and achieve a better temperature gradient setting in the crucible 120. In some embodiments, the heating power of the first induction coil 1312 can be greater than the heating power of the second induction coil 1321.

[0091] In some embodiments, the bottom end of the second induction coil 1321 in the axial direction is spaced from the top end of the first induction coil 1312 in the axial direction to avoid mutual influence between the first induction coil 1312 and the second induction coil 1321. The top end of the second induction coil 1321 in the axial direction is on the same horizontal line (perpendicular to the axial direction) as the top end of the crucible 120 in the axial direction, or the top end of the second induction coil 1321 in the axial direction is higher than the top end of the crucible 120 in the axial direction. The bottom end of the first induction coil 1312 in the axial direction is lower than the bottom end of the crucible 120 in the axial direction, or the lower end of the first induction coil 1312 in the axial direction is on the same horizontal line (perpendicular to the axial direction) as the bottom end of the crucible 120 in the axial direction. In some embodiments, the central axis of the first induction coil 1312 and the central axis of the second induction coil 1321 both coincide with the central axis of the crucible 120. About Figure 5 For more information about the first induction coil 1312, please refer to Figure 3 Related content of the first induction coil 1312.

[0092] In some embodiments, an annular barrier 134 is provided between the bottom end of the second induction coil 1321 in the axial direction and the top end of the first induction coil 1312 in the axial direction, and the annular barrier 134 is used to block electromagnetic interference between the induction coils. In some embodiments, the annular barrier 134 is an annular structure, and the annular barrier 134 is arranged around the crucible 120. In some embodiments, the material of the annular barrier 134 is a material that can shield electromagnetic interference (such as aluminum, copper, iron, nickel, silver, etc.).

[0093] In some embodiments, in the crystal growth stage, in order to provide an axial temperature gradient, the first heating component 131 for bottom heating can be used as the main component, and the second heating component 132 for side heating can be used as the auxiliary component, that is, the heat given to the crucible 120 by the first heating component 131 is greater than the heat given to the crucible 120 by the second heating component 132. In some embodiments, in the crystal growth stage, the ratio of the bottom heat to the side heat obtained by the material in the crucible 120 is 1-4 (i.e., 1:1-4:1). In some embodiments, in the crystal growth stage, the ratio of the bottom heat to the side heat is 3:2-4:1 (e.g., 3:1 or 2:1). The bottom heat refers to the heat provided by the first heating component 131 and received by the crucible 120; the side heat refers to the heat provided by the second heating component 132 and received by the crucible 120. In some embodiments, the effective power ratio of the first heating component 131 to the second heating component 132 can be 3:2-4:1 (e.g., 3:1 or 2:1). In some embodiments, in the annealing stage, in order to minimize the radial temperature gradient inside the crystal, only the first heating assembly 131 may be used for heating. For the description of the crystal growth stage, please refer to the above related content.

[0094] It should be noted that Figure 2-Figure 5 The structures and arrangements of the first heating assembly 131 and the second heating assembly 132 shown are for illustration only and are not intended to be limiting. Those skilled in the art may make modifications or adjustments to the embodiments without intellectual effort. For example, the first heating assembly 13 may include a first resistance heater 1311 (in this case, the first resistance heater 1311 may be wrapped with an electromagnetic shielding shell) and a first induction coil 1312 at the same time, and the first resistance heater 1311 may be arranged in a graphite ring 133, and the graphite ring 133 separates the first induction coil 1312 and the first resistance heater 1311. These modifications or adjustments are still within the scope of this specification.

[0095] In some embodiments, the second heating assembly 132 disposed on the side of the crucible 120 may heat the side of the crucible 120 by providing a plurality of induction coils. Fig. 6A is a schematic diagram of the structure of the second heating component according to some embodiments of this specification. Fig. 6A As shown, the second heating component 132 includes a second induction coil 1321 and a third induction coil 1322, and the third induction coil 1322 is sleeved on the outside of the second induction coil 1321. The structure of the third induction coil 1322 may be similar to that of the second induction coil 1321. In some embodiments, the axial lengths of the second induction coil 1321 and the third induction coil 1322 are greater than the inner cavity height of the crucible 120 along its axial direction. By using the second induction coil 1321 and the third induction coil 1322 in conjunction, the second heating component 132 can be more flexible in regulating the temperature in the crucible 120, and the maximum heat that can be obtained in the crucible 120 can also be increased.

[0096] In some embodiments, the crystal growth device 100 includes a first induction coil moving mechanism 60 and a second induction coil moving mechanism, wherein the first induction coil moving mechanism 60 is used to drive the second induction coil 1321 to move along the axial direction of the crucible 120, and the first induction coil moving mechanism 60 is connected to the second induction coil 1321; the second induction coil moving mechanism is used to drive the third induction coil 1322 to move along the axial direction of the crucible 120, and the second induction coil driving mechanism is connected to the third induction coil 1322. In some embodiments of the present specification, the induction coil moving mechanism drives the induction coil located at the side of the crucible 120 to move along its axial direction, so as to adjust the relative position of the crucible 120 and the second heating assembly 132, thereby adjusting the position of the side of the crucible 120 that can obtain the most heat, thereby adjusting the temperature distribution inside the crucible 120 (for example, adjusting the position of the high temperature line in the crucible 120). When the second induction coil 1321 and the third induction coil 1322 are driven to move in the same direction along the axial direction of the crucible 120, it is equivalent to that the relative positions of the second induction coil 1321 and the third induction coil 1322 remain unchanged, and the position of the crucible 120 is adjusted. At this time, the temperature distribution inside the crucible 120 will also change. For details, please refer to Figure 7 and Figure 8 In some embodiments, when the second induction coil 1321 and the third induction coil 1322 are driven to move in opposite directions along the axial direction of the crucible 120, at this time, the heating temperature at the position where the second induction coil 1321 and the third induction coil 1322 overlap is the highest, and the temperature distribution inside the crucible 120 can be adjusted by adjusting the position where the second induction coil 1321 and the third induction coil 1322 overlap relative to the crucible 120 (for example, adjusting the position of the high-temperature line in the crucible 120).

[0097] Figure 6B is a schematic diagram of the structure of the second heating component and the first induction coil moving mechanism according to some embodiments of this specification. Figure 6BAs shown, the first induction coil moving mechanism 60 may include one or more suspension rods 61 and a driving member 62, the upper end of each suspension rod 61 is connected to the driving member 62, and the lower end of the suspension rod 61 is connected to the second induction coil 1321. The driving member 62 can drive the second induction coil 1321 to move axially along the crucible 120 through the suspension rod 61. The driving member 62 may include a motor, a hydraulic cylinder, a pneumatic cylinder, etc. It can be understood that the suspension rod 61 can also be replaced by a combination of a suspension rope and a pulley, and the suspension rope is wound around the pulley. At this time, the driving member 62 can drive the pulley to rotate so that the suspension rope lifts or puts down the second induction coil 1321 to adjust the axial position of the second induction coil 1321 relative to the crucible 120. In other embodiments, the first induction coil moving mechanism 60 may include a lifting mechanism disposed below the second induction coil 1321. For example, the lifting mechanism may include a telescopic rod and a driving member 62 that drives the telescopic rod to extend and retract. The telescopic rod is driven to extend and retract by the driving member 62, and the telescopic rod can be extended to lift the second induction coil 1321 or shortened to lower the second induction coil 1321, so as to adjust the axial position of the second induction coil 1321 relative to the crucible 120. The structure of the second induction coil moving mechanism can be similar to that of the first induction coil moving mechanism, and the details can refer to the relevant description of the first coil moving mechanism.

[0098] In some embodiments, the relative position of the crucible 120 and the second heating assembly may be changed and adjusted by moving the crucible 120 along the axial direction of the crucible 120. As an example only, the crucible 120 may be disposed on a lifting platform.

[0099] Figure 7 It is the axial temperature gradient diagram of the inner cavity of the crucible corresponding to the crucible at different positions. Figure 8It is the axial temperature distribution diagram of the inner cavity of the crucible when the crucible is in different positions. Under the condition that the structure, position and power input of the second induction coil 1321 and the third induction coil 1322 remain unchanged, the crucible 120 is moved up 20mm, 40mm, 60mm and down 20mm, 40mm, 60mm equidistantly in the axial direction from the original position of the crucible 120, respectively, to simulate the influence of the change of the crucible position on the temperature of the inner cavity of the crucible. In other words, the variable is only the position of the crucible 120 relative to the second induction coil 1321 and the third induction coil 1322. The tops and bottoms of the second induction coil 1321 and the third induction coil 1322 are aligned. When the crucible 120 is in the original position, the bottom ends of the second induction coil 1321 and the third induction coil 1322 are located below the bottom wall of the crucible 120, and the distance between the bottom wall of the crucible 120 and the bottom ends of the second induction coil 1321 and the third induction coil 1322 is 50mm-150mm; the top ends of the second induction coil 1321 and the third induction coil 1322 are located above the upper cover of the crucible 120, and the distance between the upper cover 121 of the crucible 120 and the top ends of the second induction coil 1321 and the third induction coil 1322 is 50mm-100mm. Figure 7 In the figure, the abscissa represents the axial position in the inner cavity of the crucible 120 ( Figure 8 , Fig. 9 , Fig. 11B The horizontal axis and Figure 7 The horizontal axis is similar to the horizontal axis of the crucible 120, and the vertical axis represents the temperature difference in the inner cavity of the crucible 120 (i.e., ° C). Figure 7 The curve in FIG. 1 can show the temperature change values ​​corresponding to different axial positions of the crucible 120 (temperature change values ​​relative to the reference position with a horizontal coordinate of 0 mm). For example, the point with a horizontal coordinate of 0 mm corresponds to the upper surface of the bottom wall of the crucible 120 ( Figure 8 , Fig. 9 , Fig. 11B The horizontal axis and Figure 7 The horizontal axis is similar to the horizontal axis of the crucible 120, and the temperature difference at this time is 0°C. The position with the horizontal axis of 0.01 mm corresponds to 0.01 mm above the upper surface of the bottom wall. For the curve where the crucible 120 moves down 60 mm, the temperature difference between the upper surface of the bottom wall of the crucible 120 and the upper surface of the bottom wall of the crucible 120 is about 4°C. Therefore Figure 7 The curve in can represent the temperature gradient in the inner cavity of the crucible 120. Figure 7It can be seen that after the crucible 120 moves upward by 60 mm from the original position, its overall axial temperature gradient is the smallest. The axial temperature gradient in the crucible 120 decreases as the height of the crucible 120 relative to the induction coils (such as the second induction coil 1321 and the third induction coil 1322) increases. The result of the crucible 120 moving downward by 60 mm from the original position is the opposite. Overall, as the position of the crucible 120 relative to the induction coils (such as the second induction coil 1321 and the third induction coil 1322) moves from bottom to top, the temperature gradient of the inner cavity of the crucible 120 gradually decreases. Figure 8 In FIG. 1 , the abscissa represents the axial position in the inner cavity of the crucible 120, and the ordinate represents the temperature (° C.) in the inner cavity of the crucible 120. Figure 8 It can be seen that compared with moving the crucible 120 downward, moving the crucible 120 upward has a greater impact on the temperature inside the crucible 120. In the process of moving the crucible 120 upward, as the height of the crucible 120 gradually increases, the overall temperature inside the crucible 120 decreases; in the process of moving the crucible downward at an equal distance, the overall temperature changes little, the temperature field changes complexly, and there is no obvious pattern. Figure 7 and Figure 8 It can be seen that the relative position of the crucible 120 and the induction coil will affect the overall temperature and temperature gradient in the crucible 120. By adjusting the axial position of the second induction coil 1321 and the third induction coil 1322 relative to the crucible 120, the overall temperature and temperature gradient inside the crucible 120 can be adjusted.

[0100] In some embodiments, the temperature distribution inside the crucible 120 can be adjusted by adjusting the power of the second induction coil 1321 and the third induction coil 1322. Fig. 9 and Fig.10 . Fig. 9 is the axial temperature distribution diagram of the inner cavity of the crucible corresponding to the third induction coil at different powers. Fig. 9 In FIG. 1 , the abscissa represents the axial position in the inner cavity of the crucible 120 , and the ordinate represents the temperature (° C.) in the inner cavity of the crucible 120 . Fig.10 It is a bar graph of the temperature difference between the seed crystal and the material surface corresponding to the third induction coil at different powers. Fig.10 In the figure, the horizontal axis represents the power of the third induction coil 1322, and the vertical axis represents the temperature difference (°C) between the seed crystal and the material surface (the upper surface of the material in the crucible 120). The power P1 of the second induction coil is set to 50kW, and the power P2 of the third induction coil is adjusted to 20kW, 30kW, 40kW, 50kW, 60kW, 70kW, and 80kW, respectively. The power P2 of the third induction coil is equal to the power of the second induction coil P1, and the experimental group with P1=P2=50kW is the control group. Fig. 9It can be seen that as the power of the third induction coil increases, the temperature in the crucible cavity gradually increases. Fig.10 It can be seen that when the power of the third induction coil is 80kW, the temperature difference between the seed crystal and the material surface is the smallest, and when the power is 20kW, the temperature difference between the seed crystal and the material surface is the largest. As the power of the third induction coil increases, the temperature difference between the seed crystal surface and the material surface gradually decreases. Fig. 9 and Fig.10 It can be seen that the power of the induction coils (such as the second induction coil 1321 and the third induction coil 1322) will affect the overall temperature and temperature gradient in the crucible 120. By adjusting the power of the second induction coil 1321 and the third induction coil 1322, the overall temperature and temperature gradient inside the crucible 120 can be adjusted.

[0101] In some embodiments, the crystal growth apparatus further includes a fourth induction coil 1323, which may be disposed below the second induction coil 1321 in the axial direction of the crucible 120. The fourth induction coil 1323 may be spaced apart from the second induction coil 1321 along the axial direction of the crucible 120. In some embodiments, the fourth induction coil 1323 may be mainly used to heat the material contained in the crucible 120. In some embodiments, the second induction coil 1321 may be mainly used to heat the area between the upper surface of the material in the crucible 120 and the crystal growth cross section. By arranging the induction coils (such as the second induction coil 1321 and the fourth induction coil 1323) at intervals along the axis of the crucible 120, the temperature of different areas of the crucible 120 may be more flexibly controlled, thereby controlling the axial temperature gradient in the crucible 120.

[0102] Fig.11A is a schematic diagram of the structure of the second heating component according to other embodiments of this specification. Fig.11AAs shown, the second heating assembly 132 includes a second induction coil 1321 and a third induction coil 1322 as well as a fourth induction coil 1323 and a fifth induction coil 1324. The second induction coil 1321 and the fourth induction coil 1323 are both arranged around the side of the crucible 120, the third induction coil 1322 is sleeved on the outside of the second induction coil 1321, and the fifth induction coil 1324 is sleeved on the outside of the fourth induction coil 1323. The fourth induction coil 1323 is arranged below the second induction coil 1321 in the axial direction, and the fifth induction coil 1324 is arranged below the third induction coil 1322 in the axial direction. In some embodiments, the bottom end of the second induction coil 1321 in the axial direction is spaced apart from the top end of the fourth induction coil 1323 in the axial direction, and the bottom end of the third induction coil 1322 in the axial direction is spaced apart from the top end of the fifth induction coil 1324 in the axial direction. In some embodiments, the top of the second induction coil 1321 in the axial direction is higher than the top of the crucible 120 in the axial direction, the bottom of the fourth induction coil 1323 in the axial direction is lower than the bottom of the crucible 120 in the axial direction, and the top of the third induction coil 1322 in the axial direction is higher than the top of the crucible 120 in the axial direction, and the bottom of the fifth induction coil 1324 in the axial direction is lower than the bottom of the crucible 120 in the axial direction. In some embodiments, the central axes of the second induction coil 1321, the third induction coil 1322, the fourth induction coil 1323, and the fifth induction coil 1324 all coincide with the central axis of the crucible 120. In some embodiments, the temperature distribution inside the crucible 120 can be adjusted by adjusting the axial positions of the second induction coil 1321, the third induction coil 1322, the fourth induction coil 1323, and the fifth induction coil 1324 relative to the crucible 120, and / or adjusting the power of the second induction coil 1321, the third induction coil 1322, the fourth induction coil 1323, and the fifth induction coil 1324, respectively.

[0103] By setting the above-mentioned four induction coils (the second induction coil 1321, the third induction coil 1322, the fourth induction coil 1323 and the fifth induction coil 1324), the second induction coil 1321 and the third induction coil 1322 located at the upper part and the fourth induction coil 1323 and the fifth induction coil 1324 located at the lower part respectively heat different axial areas of the crucible 120, so that the radial temperature of the crucible 120 can be adjusted more flexibly, and the adjustable temperature range is also larger.

[0104] In some embodiments, the fourth induction coil 1323 and / or the fifth induction coil 1324 may also be connected to an induction coil moving mechanism so that the position of the fourth induction coil 1323 and / or the fifth induction coil 1324 relative to the crucible 120 can be changed. For example, the fourth induction coil 1323 may be connected to the third induction coil moving mechanism, and the fifth induction coil 1324 may be connected to the fourth induction coil moving mechanism. The structure of the third induction coil moving mechanism and the structure of the fourth induction coil moving mechanism may be similar to the structure of the first induction coil moving mechanism.

[0105] In some embodiments, the temperature distribution inside the crucible 120 can be adjusted by adjusting the power of the second induction coil 1321, the third induction coil 1322, the fourth induction coil 1323, and the fifth induction coil 1324. For details, refer to Fig. 11B and Fig. 11C . Fig. 11B is the axial temperature distribution diagram of the inner cavity of the crucible corresponding to the fourth induction coil and the fifth induction coil at different powers. Fig. 11B In FIG. 1 , the abscissa represents the axial position in the inner cavity of the crucible 120 , and the ordinate represents the temperature (° C.) in the inner cavity of the crucible 120 . Fig. 11C It is a bar graph of the temperature difference between the seed crystal and the material surface corresponding to the fourth induction coil and the fifth induction coil at different powers. Fig. 11C In the figure, the horizontal axis represents the power P3 of the fourth induction coil 1323 (the power P4 of the fifth induction coil 1324 = P3), and the vertical axis represents the temperature difference (°C) between the seed crystal and the material surface (the upper surface of the material in the crucible 120). Make the power P1 of the second induction coil 1321 and the power P2 of the third induction coil 1322 equal, both are 50kW, and make the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 equal. Adjust the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 to be equal and to be 20kW, 30kW, 40kW, 50kW, 60kW, 70kW, 80kW respectively. Among them, the experimental group in which the power P1 of the second induction coil 1321, the power P2 of the third induction coil 1322, the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 are equal and all are 50kW is the control group. By Fig. 11B It can be seen that as the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 increase, the temperature in the inner cavity of the crucible 120 gradually increases. Fig. 11CIt can be seen that when the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 are 80kW, the temperature difference between the seed crystal and the material surface is the largest, and when the power is 20kW, the temperature difference between the seed crystal and the material surface is the smallest. As the power P3 of the fourth induction coil 1323 and the power P4 of the fifth induction coil 1324 increase, the temperature difference between the seed crystal surface and the material surface also gradually increases. Fig. 11B and Fig. 11C It can be seen that the power of the induction coils (such as the fourth induction coil 1323 and the fifth induction coil 1324) will affect the overall temperature and temperature gradient in the crucible 120. By adjusting the fourth induction coil 1323 and the fifth induction coil 1324, the overall temperature and temperature gradient inside the crucible 120 can be adjusted.

[0106] Fig.12 Schematic diagram of the structure of the crystal growth equipment according to other embodiments of this specification. Fig.12 As shown, based on the above embodiment, the heating assembly 130 further includes a third heating assembly 135, and the third heating assembly 135 heats the top of the crucible 120. Fig.12 In the illustrated embodiment, the heating assembly 130 includes a first heating assembly 131, a second heating assembly 132 and a third heating assembly 135. It can be understood that the third heating assembly 135 can be provided separately (not combined with the first heating assembly 131 and the second heating assembly 132), and the third heating assembly 135 can also be combined with any one of the first heating assembly 131 and the second heating assembly 132. The third heating assembly 135 heats the top of the crucible 120, which can be understood as the third heating assembly 135 is mainly used to heat the top of the crucible 120, that is, the heat provided to the top by the third heating assembly 135 is higher than the heat provided to other parts of the crucible (such as the side and the bottom) by the third heating assembly 135. By combining the third heating component 135 with the first heating component 131, the third heating component 135 with the second heating component 132, or the first heating component 131, the second heating component 132, and the third heating component 135, the crucible 120 can be heated from multiple different locations, and the heating of various locations of the crucible 120 (e.g., bottom heating, side heating, top heating) can be controlled separately, which is beneficial to regulating the temperature gradient (including axial temperature gradient and radial temperature gradient) in the inner cavity of the crucible 120.

[0107] In some embodiments, the third heating assembly 135 includes a second resistance heater 1351, and heating is achieved by resistive heating. In some embodiments, the second resistance heater 1351 can be arranged along a surface parallel to the upper cover of the crucible 120, and can be spaced apart from the upper cover of the crucible 120. In some embodiments, the projection coverage area of ​​the second resistance heater 1351 along the axial direction can be greater than or equal to the projection coverage area of ​​the inner cavity of the crucible 120 along the axial direction, so that the heat radiation range of the second resistance heater 1351 can include the inside of the crucible 120. In some embodiments, to avoid the phenomenon of resistive heating ignition, the distance between the second resistance heater 1351 and the top wall of the crucible 120 along the axial direction can be greater than 20mm (for example, greater than 25mm or greater than 30mm). In some embodiments, the second resistance heater 1351 includes a resistance wire, and the relevant content of the resistance wire included in the second resistance heater 1351 can refer to the description of the resistance wire 13111. In some embodiments, the second resistance heater 1351 can be embedded in the top of the crucible 120.

[0108] In some embodiments, the third heating assembly 135 includes an induction coil, which is heated by electromagnetic induction. The relevant contents of the induction coil included in the third heating assembly 135 can refer to the description of the first induction coil 1312. For example, a graphite ring can also be set on the top of the crucible 120, and the induction coil of the third heating assembly 135 can at least partially surround the outside of the graphite ring on the top of the crucible 120.

[0109] In some embodiments, during the crystal growth stage, the third heating assembly 135 may also heat the crucible 120. In some embodiments, during the crystal growth stage, the ratio of the side heat to the top heat obtained by the material in the crucible is 1-3. In some embodiments, during the crystal growth stage, the ratio of the bottom heat to the top heat obtained by the material in the crucible is 1-8.

[0110] In some embodiments of the present specification, the temperature distribution in the crucible 120 is controlled and adjusted by heating the bottom, side and top of the crucible 120 through the first heating component 131, the second heating component 132 and the third heating component 135 respectively. In some embodiments, in the crystal growth stage, in order to ensure the best gas phase and temperature gradient, the heat given to the crucible 120 by the heating component 130, that is, the heat obtained by the material 140 in the crucible 120, is mainly provided by the first heating component 131 for bottom heating, and supplemented by the second heating component 132 and the third heating component 135 for side heating and top heating. In some embodiments, in the crystal growth stage, the ratio of bottom heat, side heat and top heat is 8:3:1-1:1:1 (for example, 5:3:1, 5:2:1 or 3:2:1). The bottom heat refers to the heat provided by the first heating component 131 and received by the bottom of the crucible 120; the side heat refers to the heat provided by the first heating component 131 or the second heating component 132 and received by the side of the crucible 120; the top heat refers to the heat provided by the third heating component 135 and received by the top of the crucible 120. In some embodiments, the effective power ratio of the first heating component 131, the second heating component 132 and the third heating component 135 can be regarded as 8:3:1-1:1:1. In some embodiments, in the annealing stage, in order to minimize the radial temperature gradient inside the crystal, the first heating component 131 for bottom heating can be used as the main heating component, and the second heating component 132 for side heating can be used as the auxiliary heating component, or only the first heating component 131 at the bottom of the crucible 120 can do work. In some embodiments, in the annealing stage, the ratio of the bottom heat to the side heat is 5:1-1.5:1 (e.g., 4:1, 3:1, 2:1).

[0111] Fig.13 is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification. Fig.13 As shown, the crystal growth apparatus 100 may include a second heating assembly 132 and a third heating assembly 135. By respectively arranging the second heating assembly 132 and the third heating assembly 135 on the side and the top of the crucible 120, the temperature distribution in the crucible 120 is controlled and adjusted. In some embodiments, the second heating assembly 132 may be used during the crystal growth stage. If a higher temperature of the inner cavity of the crucible 120 is required, the third heating assembly 135 may be used as an auxiliary. In some embodiments, during the annealing stage, in order to minimize the radial temperature gradient inside the crystal, only the third heating assembly 135 on the top of the crucible 120 does work, which can effectively reduce the stress during the cooling process.

[0112] The present specification also provides a crystal growth method, which includes: in the crystal growth stage, heating the crucible 120 by the first heating component 131 and the second heating component 132; in the annealing stage, heating the crucible 120 by the second heating component 132 and the third heating component 135. In the crystal growth stage, in order to ensure a suitable axial temperature gradient to drive the gas phase components to be transported to the crystal growth interface, a relatively ideal temperature gradient can be formed by the cooperation of the first heating component 131 and the second heating component 132, and at this time, the third heating component 135 does not work, which will not cause a decrease in the axial temperature gradient. In the annealing stage, in order to minimize the radial temperature gradient inside the crystal, the third heating component 135 can be used as the main heating component and the second heating component 132 can be used as the auxiliary heating component.

[0113] In some embodiments, the crystal includes a silicon carbide crystal. Graphite inclusions are produced during the growth of the silicon carbide crystal. In the early stage of crystal growth, the temperature in the cavity is low, the pressure of the silicon carbide gas phase component in the crucible cavity is low, the growth rate is slow, and the material graphitization has not yet begun. As the growth proceeds, the pressure of the gas phase component in the crucible cavity gradually increases, and the material begins to graphitize. The fine particles after graphitization are very likely to be brought to the growth surface by the convection of the gas phase component in the crucible cavity, and graphite inclusions are produced in the crystal. The presence of graphite inclusions will cause lattice distortion and generate stress, and will also induce defects such as microtubes, dislocations, and stacking faults, which will seriously affect the product quality of silicon carbide.

[0114] Therefore, in order to suppress the generation of graphite inclusions, in some embodiments, the crystal growth apparatus 100 includes a filtering structure disposed in the inner cavity of the crucible. Fig.14 It is a schematic diagram of the structure of the filtering structure shown in some embodiments of this specification.

[0115] In some embodiments, Fig.14 As shown, the filter structure 150 is located above the material 140 in the crucible 120 in the axial direction, and the filter structure 150 includes a through hole 151 that penetrates the filter structure 150 from top to bottom along the axial direction of the crucible 120. The filter structure 150 can block the carbonized fine particles from reaching the growth surface under the convection of the gas phase components in the crucible 120 cavity, thereby avoiding the generation of graphite inclusions in the crystal. In some embodiments, the peripheral side of the filter structure 150 is connected to the inner wall of the crucible 120, dividing the inner cavity of the crucible 120 along the axial direction. The through hole can allow gas phase components to pass through, but the filter structure 150 will block the passage of graphitized fine particles, thereby achieving the effect of suppressing the generation of graphite inclusions and uniformizing the transmission of airflow. It should be noted that Fig.14 The through hole 151 is only an example and is not intended to be a description or limitation of its size.

[0116] In some embodiments, the porosity of the filter structure 150 is in the range of 5% to 40% (e.g., 10% to 35%, 15% to 25%), where the porosity refers to the ratio of the pore area to the surface area of ​​the filter structure 150. If the porosity of the filter structure 150 is too large, it will not be able to effectively inhibit the generation of graphite inclusions. If the porosity of the filter structure 150 is too small, it will affect the transmission of gas phase components. When the porosity of the filter structure 150 is controlled within the range of 5% to 40%, it can inhibit the generation of graphite inclusions without affecting the transmission of gas phase components, and can grow crystals with better quality.

[0117] In some embodiments, the aperture of the through hole 151 on the filter structure 150 ranges from 5 μm to 100 μm. In some embodiments, the aperture of the through hole 151 on the filter structure 150 ranges from 5 μm to 80 μm. In some embodiments, the aperture of the through hole 151 on the filter structure 150 ranges from 10 μm to 50 μm. It should be noted that Fig.14 The through holes 151 in the figure are only for illustration and do not represent their size. In some embodiments, the through holes are axially symmetrically distributed on the filter structure 150 (the axis of symmetry can be the diameter of the filter structure 150), so that the airflow in the crucible 120 cavity is evenly transmitted. In some embodiments, the through holes are rotationally symmetrically distributed on the filter structure 150, further making the airflow in the crucible 120 cavity evenly transmitted. In some embodiments, the size and position of the through holes can be set according to the enrichment distribution of graphite in the crucible 120 cavity. It was found that the carbonization of the peripheral area in the crucible 120 cavity was more serious (more fine particles after carbonization), and the pore size of the through holes in the edge area of ​​the filter structure 150 was smaller than the pore size of the through holes 151 in the central area of ​​the filter structure 150, so as to better prevent the fine particles after carbonization from reaching the crystals. In some embodiments, the porosity of the through holes 151 in the edge area of ​​the filter structure 150 is greater than the porosity of the through holes 151 in the central area of ​​the filter structure. Since the pore size of the through hole 151 in the edge area of ​​the filter structure 150 is relatively small, in order to avoid the edge area of ​​the filter structure 150 hindering the transmission of the gas phase components, the porosity of the through hole 151 in the edge area of ​​the filter structure 150 is increased, which can better inhibit the generation of graphite inclusions and ensure the temperature transmission of the gas phase components.

[0118] In some embodiments, the material of the filter structure 150 may be a material that does not react with the gas phase component. In some embodiments, the material of the filter structure 150 includes graphite. In some embodiments, the material of the filter structure 150 includes one or more of tantalum, tungsten, titanium, and corresponding nitrides or carbides.

[0119] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0120] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0121] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

Claims

1. A crystal growth device, characterized in that: The device includes a furnace body, a crucible and a heating assembly; wherein the furnace body includes a furnace chamber, and the crucible and the heating assembly are both arranged in the furnace chamber; the heating assembly heats the crucible; the heating assembly includes a first heating assembly and / or a second heating assembly, wherein the first heating assembly heats the bottom of the crucible; and the second heating assembly heats the side of the crucible.

2. The crystal growth device according to claim 1, characterized in that The second heating assembly includes a second induction coil; the second induction coil is arranged around the side wall of the crucible; The first heating assembly comprises a first induction coil, and the first induction coil is arranged around the bottom wall of the crucible; or, The first heating component includes a first resistance heater, and the first heating component is arranged below the bottom wall of the crucible.

3. The crystal growth device according to claim 2, characterized in that: A graphite ring is provided at the bottom of the crucible, and the first induction coil at least partially surrounds the outside of the graphite ring; or The first resistance heater is embedded in the bottom wall of the crucible.

4. The crystal growth device according to claim 3, characterized in that An annular barrier is provided between the first induction coil and the second induction coil, and the annular barrier is arranged around the crucible.

5. The crystal growth device according to claim 2, characterized in that: The heating assembly further includes a third heating assembly, and the third heating assembly heats the top of the crucible.

6. The crystal growth device according to claim 5, characterized in that The third heating assembly includes a second resistive heater; The distances between the first resistance heater and the second resistance heater and the crucible are both greater than 20 mm; and / or, The first resistance heater and / or the second resistance heater include resistance wires, and a minimum spacing distance between the resistance wires is in the range of 10 mm-15 mm.

7. The crystal growth apparatus according to claim 5, characterized in that During the crystal growth stage, the ratio of bottom heat to side heat obtained by the material in the crucible is 1-4, and the ratio of side heat to top heat is 1-3; during the annealing stage, the ratio of top heat to side heat obtained by the material in the crucible is in the range of 1.5-5, the bottom heat is provided by the first heating component, the side heat is provided by the second heating component, and the top heat is provided by the third heating component.

8. The crystal growth apparatus according to claim 2, characterized in that The second heating component also includes a third induction coil, and the third induction coil is sleeved outside the second induction coil.

9. The crystal growth apparatus according to claim 8, characterized in that The power of the first induction coil is greater than the power of the second induction coil.

10. The crystal growth apparatus according to claim 8, characterized in that The device also includes: a first induction coil moving mechanism, used for driving the second induction coil to move along the axial direction of the crucible, the first induction coil moving mechanism being connected to the second induction coil; The second induction coil moving mechanism is used to drive the third induction coil to move along the axial direction of the crucible, and the second induction coil driving mechanism is connected to the third induction coil.

11. The crystal growth apparatus according to claim 8, characterized in that The device further comprises a fourth induction coil and a fifth induction coil, wherein the fourth induction coil is arranged below the second induction coil in the axial direction of the crucible; The fifth induction coil is sleeved on the outside of the fourth induction coil, and the fifth induction coil is arranged below the third induction coil in the axial direction of the crucible.

12. The crystal growth apparatus according to claim 1, characterized in that The device also includes a filtering structure arranged in the furnace, the filtering structure is located above the material in the crucible in the axial direction of the crucible, wherein the filtering structure includes a through hole that penetrates the filtering structure from top to bottom along the axial direction of the crucible.

13. The crystal growth apparatus according to claim 12, characterized in that The material of the filter structure includes graphite; or The material of the filter structure includes one or more of tantalum, tungsten, titanium and corresponding nitrides or carbides.

14. The crystal growth apparatus according to claim 12, characterized in that The pore size of the through holes in the edge region of the filter structure is smaller than that of the through holes in the central region of the filter structure, and the porosity of the through holes in the edge region of the filter structure is greater than that of the through holes in the central region of the filter structure.

15. The crystal growth apparatus according to claim 12, characterized in that The porosity of the filter structure is in the range of 5% to 40%.

16. A crystal growth method, characterized in that: Using the crystal growth apparatus according to claim 5, the process of crystal growth includes a crystal growth stage and an annealing stage, and the method includes: During the crystal growth stage, the crucible is heated by a first heating component and a second heating component; During the annealing stage, the crucible is heated by the second heating assembly and the third heating assembly.

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