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 hearth comprises a plurality of cavities, the number of the crucibles is multiple, and the multiple crucibles are arranged in the multiple cavities respectively; the crystal growth equipment further comprises a conveying mechanism, at least part of the conveying mechanism is located in the hearth, the multiple cavities are arranged in the conveying direction of the conveying mechanism, and the conveying mechanism conveys the multiple crucibles so that the multiple crucibles can move among the different cavities.

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 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 furnace chamber includes a plurality of chambers, and there are a plurality of crucibles, and the plurality of crucibles are respectively arranged in the plurality of chambers; the crystal growth device also includes a conveying mechanism, at least part of which is located in the furnace chamber, and the plurality of chambers are arranged along the conveying direction of the conveying mechanism, and the conveying mechanism conveys the plurality of crucibles so that the plurality of crucibles move between different chambers.

[0004] In some embodiments, the multiple chambers form a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are arranged along the conveying direction; the maximum temperature in the second chamber is higher than the maximum temperature in the first chamber, and the maximum temperature in the second chamber is higher than the maximum temperature in the third chamber; the maximum pressure in the second chamber is lower than the maximum pressure in the first chamber, and the maximum pressure in the second chamber is lower than the maximum pressure in the third chamber.

[0005] In some embodiments, the crystal growth process includes a preheating stage, a crystal growth stage and an annealing stage, the crystal production in the crucible in the first chamber is in the preheating stage, the crystal production in the crucible in the second chamber is in the crystal growth stage, and the crystal production in the crucible in the third chamber is in the annealing stage.

[0006] In some embodiments, a passage and an openable and closable partition are provided between two adjacent chambers.

[0007] In some embodiments, the heating assembly includes at least one induction coil and at least one coil pulling device, at least one of the induction coil and at least one of the coil pulling devices are arranged in at least one of the chambers, the coil pulling device is correspondingly connected to the induction coil, and the coil pulling device can pull the induction coil along the axial direction of the crucible.

[0008] In some embodiments, the device further comprises a plurality of heat-insulating structures, which are arranged one by one on the outside of the plurality of crucibles; the heat-insulating structure comprises a side heat-insulating portion and a top heat-insulating portion, and a temperature measuring port is provided on the top heat-insulating portion.

[0009] In some embodiments, a temperature measuring mechanism is further included, and the temperature measuring mechanism capable of extending into the temperature measuring port is telescopically arranged.

[0010] In some embodiments, the crystal growth equipment includes a first temperature measuring component, which includes a first electrical rail and a plurality of first thermometers, wherein the plurality of first thermometers respectively measure the temperature in the inner cavity of the plurality of crucibles, the first electrical rail is arranged on the outside of the crucible, and a portion of each of the plurality of first thermometers that passes through the crucible is in sliding electrical contact with the first electrical rail, and the first electrical rail is parallel to the conveying direction of the conveying mechanism.

[0011] In some embodiments, a sealing structure is provided at the position on the crucible where the first thermometer passes through.

[0012] In some embodiments, the crystal growth equipment further comprises a plurality of resistance heaters, which are respectively disposed in the plurality of chambers and respectively located at the bottom of the plurality of crucibles, and the plurality of resistance heaters are disposed below the conveying mechanism in the axial direction of the crucible. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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:

[0014] Figure 1 is a block diagram of a crystal growth apparatus according to some embodiments of the present specification;

[0015] Figure 2 is a schematic diagram of the structure of a crystal growth device according to some embodiments of this specification;

[0016] Figure 3 is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification;

[0017] Figure 4 is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification;

[0018] Figure 5 It is a schematic diagram of the structure of a coil pulling device according to some embodiments of the present specification.

[0019] Explanation of the reference numerals: 100, crystal growth equipment; 110, furnace body; 111, first chamber; 112, second chamber; 113, third chamber; 114, partition; 120, crucible; 130, heating assembly; 121, upper cover; 122, main body; 131, first heating assembly; 132, second heating assembly; 136, resistance heater; 137, induction coil; 140, material; 160, insulation structure; 161, top insulation part; 162, side insulation part; 163, temperature measuring port; 170, conveying mechanism; 171, belt conveying mechanism; 180, first temperature measuring assembly; 181, first electric rail; 182, first thermometer; 138, coil pulling device; 1381, suspension rod; 1382, driving member; 200, seed crystal. DETAILED DESCRIPTION

[0020] 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.

[0021] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0022] 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.

[0023] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0024] 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 .

[0025] 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.

[0026] 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.

[0027] 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 .

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In some embodiments, at least one temperature measuring component ( Figure 2 (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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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:

[0041] 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.

[0042] Step 1 can be viewed as an operation that is performed in the preparatory stage of the crystal growth process.

[0043] 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.

[0044] 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. 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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~3°C / min). In some embodiments, the changes in pressure and / or temperature in the crucible 120 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.

[0049] In some embodiments, during the preheating stage, an inert gas (eg, argon) may be introduced into the crucible 120 to control the pressure to be maintained at 400 Pa to 800 Pa. In some embodiments, an inert gas (eg, argon) may be introduced into the crucible 120 to control the pressure to be maintained at 450 Pa to 800 Pa.

[0050] In some embodiments, during the crystal growth stage, the temperature of the crucible 120 is maintained in the range of 2100° C. to 2400° C. when the material 140 is sublimated. In some embodiments, during the crystal growth stage, the temperature of the crucible 120 is maintained in the range of 2150° C. to 2400° C. when the material 140 is sublimated.

[0051] In some embodiments, the material 140 will sublime during 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 40 hours to 55 hours. In some embodiments, the constant pressure time of the constant pressure cooling stage can also be one of 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours, 50 hours, 52 hours, 54 hours, 56 hours, 58 hours, 60 hours, etc.

[0052] 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.

[0053] 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.

[0054] Figure 2 Schematic diagram of the structure of the crystal growth equipment shown in some embodiments of this specification. Figure 2 As 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 fact that the first heating assembly 131 heats the bottom of the crucible 120 can be understood as that the first heating assembly 131 is mainly used to heat the bottom of the crucible 120, that is, the heat provided to the bottom by the first heating assembly 131 is higher than the heat provided to other parts of the crucible (such as the side and the top) by the first heating assembly 131. 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 may 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.

[0055] 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.

[0056] Figure 3 Schematic diagram of the structure of the crystal growth equipment according to some embodiments of this specification. Figure 3 As shown, the furnace of the furnace body 110 includes a plurality of chambers, and the number of crucibles 120 is multiple, and the plurality of crucibles 120 are respectively arranged in the plurality of chambers. Specifically, a crucible 120 is correspondingly arranged in one chamber. The crystal growth device 100 also includes a conveying mechanism 170, which is located in the furnace, and the plurality of chambers are arranged along the conveying direction of the conveying mechanism 170. The conveying mechanism 170 conveys the plurality of crucibles 120 so that the plurality of crucibles 120 move between different chambers. In some embodiments, the crystal growth in the crucibles 120 in different chambers may be at different stages. In some embodiments, the temperature in different chambers is different. In some embodiments, the conveying mechanism 170 may include a belt conveying mechanism 171, a chain transmission mechanism, a push rod or a pull rod, etc. A passage is provided between adjacent chambers so that the crucible 120 can move between different chambers. The conveying mechanism 170 may be arranged at the top, bottom, etc. of the furnace. It should be noted that the conveying mechanism 170 being located in the furnace may mean that the conveying mechanism 170 is completely located in the furnace, or may mean that part of the structure of the conveying mechanism 170 is located in the furnace, and the conveying mechanism 170 can realize the movement of the crucible 120 between different chambers. As an example only, both ends of the conveying direction of the belt conveying mechanism 171 may be located outside the furnace.

[0057] In some embodiments, the crystal growth in the crucibles in the multiple chambers is at the same or different stages. In some embodiments, the number of chambers is at least three. That is, the multiple chambers may include a first chamber 111, a second chamber 112, and a third chamber 113. The first chamber 111, the second chamber 112, and the third chamber 113 are arranged along the conveying direction. The maximum temperature in the second chamber 112 is higher than the maximum temperature in the first chamber 111, and the maximum temperature in the second chamber 112 is higher than the maximum temperature in the third chamber 113. The maximum pressure in the second chamber 112 is lower than the maximum pressure in the first chamber 111, and the maximum pressure in the second chamber 112 is lower than the maximum pressure in the third chamber 113. The temperature and pressure settings of the first chamber 111, the second chamber 112, and the third chamber 113 are in accordance with the temperature and pressure change process during the crystal growth process, so that each chamber can match the temperature and pressure change process during the crystal growth process, which is conducive to convenient and efficient growth of crystals.

[0058] Referring to the above, since the crystal growth process may include a preheating stage, a crystal growth stage, and an annealing stage, at least three chambers may be respectively arranged corresponding to the preheating stage, the crystal growth stage, and the annealing stage to form a first chamber 111, a second chamber 112, and a third chamber 113. In some embodiments, the crystal growth in the crucible 120 in the first chamber 111, the second chamber 112, and the third chamber 113 is in different stages. The crystal production in the crucible 120 in the first chamber 111 is in the preheating stage, the crystal production in the crucible 120 in the second chamber 112 is in the crystal growth stage, and the crystal production in the crucible 120 in the third chamber 113 is in the annealing stage. Among them, the temperature range in the crucible 120 of the first chamber 111 is the temperature range in the crucible 120 corresponding to the preheating stage; the temperature range in the crucible 120 of the second chamber 112 is the temperature range in the crucible 120 corresponding to the crystal growth stage; the temperature range in the crucible 120 of the third chamber 113 is the temperature range in the crucible 120 corresponding to the annealing stage.

[0059] By setting the chamber in correspondence with the stage of crystal growth, each crucible 120 can be placed in the corresponding chamber at each stage of crystal growth in the crucible 120, and the movement of the crucible 120 between different chambers can be conveniently completed by means of a conveying mechanism. The temperature in the chamber only needs to be set in accordance with the crystal growth stage and can be adjusted within the temperature range of the corresponding crystal growth stage. In this way, crystal growth of multiple crucibles 120 can be performed simultaneously, and there is no need for frequent heating and cooling for a single chamber, thus achieving continuous production of crystals and greatly improving the output efficiency of crystals.

[0060] In some embodiments, an openable and closable partition 114 is provided between two adjacent chambers, and the partition 114 can isolate the two adjacent chambers. In some embodiments, the partition 114 can open or close the passage between the two adjacent chambers. When the partition 114 is closed, the two adjacent chambers are isolated to prevent the pressure and temperature between the two adjacent chambers from affecting each other. When the crucible 120 needs to be moved, the partition 114 can be opened to allow the crucible 120 to pass through, so as to prevent the partition 114 from affecting the movement of the crucible 120.

[0061] In some embodiments, each of the first chamber 111, the second chamber 112, and the third chamber 113 may be provided with Figure 2 The heating assembly 130 heats the crucible 120. In other embodiments, the heating assembly 130 in each of the first chamber 111, the second chamber 112, and the third chamber 113 may include only the first heating assembly 131, or only the second heating assembly 132. In some embodiments, the heating assembly 130 includes a plurality of resistance heaters 136, and the plurality of resistance heaters 136 are respectively disposed in a plurality of chambers. Specifically, one resistance heater 136 is correspondingly disposed in one chamber. The resistance heater 135 is located at the bottom of the plurality of crucibles 120 to heat the bottom of the crucible 120.

[0062] In some embodiments, the resistance heater 136 is disposed axially below the belt conveyor 171. The distance between the resistance heater 136 and the belt conveyor 171 in the axial direction of the crucible 120 is in the range of 30 mm to 10 mm (eg, 25 mm, 20 mm, or 15 mm).

[0063] In some embodiments, the heating assembly 130 includes at least one induction coil 137, and at least one induction coil 137 is disposed in at least one chamber. The induction coil 137 is disposed around the crucible 120 and is located at the side of the crucible 120 to heat the side of the crucible 120. In some embodiments, since the crystal growth stage requires a higher temperature in the crucible 120 (if both the axial temperature gradient and the radial temperature gradient in the crucible 120 have higher requirements), the induction coil 137 is disposed in the second chamber 112, and is disposed around the crucible 120 in the second chamber 112, and heats the side of the crucible 120 in the second chamber 112 to increase the temperature in the crucible 120. In some embodiments, to prevent the induction coil 137 from affecting the conveying mechanism to convey the crucible 120, the heating assembly 130 includes at least one coil pulling device 138, and at least one coil pulling device 138 is disposed in the chamber where the induction coil 137 is located, and the coil pulling device 138 can pull the induction coil 137 along the axial direction. In some embodiments, when the induction coil 137 is disposed in the second chamber 112, the coil pulling device 138 is also correspondingly disposed in the second chamber 112. In addition, the coil pulling device 138 can also adjust the position of the induction coil 137 relative to the crucible 120 surrounded by the induction coil 137 in the axial direction of the crucible 120, thereby adjusting the temperature field distribution (such as the axial temperature gradient) in the corresponding crucible 120.

[0064] In some embodiments, the coil pulling device 138 is used to drive the induction coil 137 to move along the axial direction of the crucible 120, and the coil pulling device 138 is connected to the induction coil 137. In some embodiments of the present specification, the coil pulling device 138 drives the induction coil 137 to move along its axial direction, so as to adjust the relative position of the crucible 120 and the induction coil 137, 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).

[0065] Figure 5 is a schematic diagram of the structure of the coil pulling device according to some embodiments of this specification. In some embodiments, Figure 5As shown, the coil pulling device 138 may include one or more suspension rods 1381 and a driving member 1382, the upper end of each suspension rod 1381 is connected to the driving member 1382, and the lower end of the suspension rod 1381 is connected to the induction coil 137. The driving member 1382 can drive the induction coil 137 to move axially along the crucible 120 through the suspension rod 1381. The driving member 1382 may include a motor, a hydraulic cylinder, a pneumatic cylinder, etc. It can be understood that the suspension rod 1381 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 1382 can drive the pulley to rotate so that the suspension rope lifts or puts down the induction coil 137 to adjust the axial position of the induction coil 137 relative to the crucible 120. In other embodiments, the coil pulling device 138 may include a lifting mechanism disposed below the induction coil 137. For example, the lifting mechanism may include a telescopic rod and a driving member 1382 that drives the telescopic rod to extend and retract. The driving member 1382 drives the telescopic rod to extend and retract. The telescopic rod can be extended to lift the induction coil 137 or shortened to lower the induction coil 137 , so as to adjust the axial position of the induction coil 137 relative to the crucible 120 .

[0066] In some embodiments, the relative position of the crucible 120 and the induction coil 137 can be changed and adjusted by moving the crucible 120 along the axial direction of the crucible 120. As an example only, the crucible 120 can be disposed on a lifting platform.

[0067] In some embodiments, the crystal growth device further includes a plurality of insulation structures 160, and the plurality of insulation structures 160 are respectively arranged in a plurality of chambers. The plurality of insulation structures 160 are arranged one by one on the outside of the plurality of crucibles 120. The insulation structure 160 is arranged to wrap the crucible 120 to keep the crucible 120 warm. In some embodiments, the insulation structure 160 includes a top insulation portion 161 and a side insulation portion 162, the top insulation portion 161 is located at the top of the crucible 120, and the side insulation portion 162 is located at the side of the crucible 120. In some embodiments, the top end of the side insulation portion 162 along the axial direction is connected to the top insulation portion 161. In some embodiments, a temperature measuring port 163 is provided on the top insulation portion 161, and the temperature measuring port 163 passes through the top insulation portion 161, and the temperature measuring port 163 is used for a thermometer to extend into for temperature measurement. In some embodiments, the crystal growth device further includes a temperature measuring mechanism, and the temperature measured by the temperature measuring mechanism extending through the temperature measuring port 163 is the temperature of the top of the upper cover 121 of the crucible 120. In some embodiments, the temperature measuring mechanism that can extend into the temperature measuring port 163 can be arranged in a retractable manner, for example, the temperature measuring mechanism itself is a retractable structure, or the temperature measuring mechanism is connected to the retractable structure. That is, when the temperature needs to be measured, the retractable structure is extended, and the temperature measuring mechanism extends into the temperature measuring port 163; when the conveying mechanism 170 conveys the crucible 120, the retractable structure is retracted, and the temperature measuring mechanism leaves the temperature measuring port 163.

[0068] In some embodiments, the crystal growth apparatus 100 includes a plurality of chambers, each of which can measure temperature and pressure separately, so as to control the temperature and pressure in each chamber separately. In some embodiments, each chamber is provided with a device for sensing temperature and pressure separately. Figure 4 Schematic diagram of the structure of the crystal growth equipment shown in some embodiments of this specification. Figure 4 As shown, in some embodiments, the crystal growth device includes a first temperature measuring component 180, the first temperature measuring component 180 includes a first electric rail 181 and a plurality of first thermometers 182, the plurality of first thermometers 182 respectively measure the temperature in the inner cavity of the plurality of crucibles 120, the first electric rail 181 is arranged outside the crucible 120, and the portion of each of the plurality of first thermometers 182 that passes through the crucible is in sliding electrical contact with the first electric rail 181. The first electric rail 181 is parallel to the conveying direction of the conveying mechanism 170. The first electric rail 181 is located in the furnace and extends in a plurality of chambers. When the conveying mechanism 170 conveys the crucible 120, the first thermometer 182 moves synchronously with the crucible 120. The first thermometer 182 is in sliding electrical contact with the first electric rail 181, so that the first electric rail 181 can supply power to the first thermometer 182 in real time. In some embodiments, the temperature signal detected by the first thermometer 182 can be derived through the first electric rail 181. With such an arrangement, the first thermometer 182 can continuously measure the temperature of the crucible 120 during the process of being transported by the transport mechanism 170 , and the measured temperature can also be conveniently transmitted.

[0069] In some embodiments, the first thermometer is fixed at the temperature measuring port 163 for temperature measurement. The first electrical rail is located at the upper part of the crucible 120 in the axial direction. Specifically, the first thermometer is kept in the temperature measuring port 163, and the part passing through the temperature measuring port 163 is kept in sliding electrical contact with the first electrical rail. When the crucible 120 is transported by the conveying mechanism 170, the first thermometer slides relative to the first electrical rail, and the temperature is monitored during the movement of the crucible 120. In other embodiments, the first thermometer can be fixed on the side wall or the bottom wall of the crucible 120, and the first thermometer passes through the side wall or the bottom wall of the crucible 120. This makes it easy to measure the temperature of the material in the crucible 120. In some embodiments, a sealing structure can be provided at the position on the side wall or the bottom wall of the crucible 120 where the first thermometer passes through.

[0070] In some embodiments, each chamber (such as the first chamber 111, the second chamber 112, and the third chamber 113) may be provided with a pressure control mechanism to control the pressure in each chamber. In some embodiments, the pressure control mechanism may include a butterfly valve, a mechanical pump, and the like.

[0071] As an example only, the transfer of a certain crucible 120 in multiple chambers is used as an example for explanation. In the first chamber 111, the temperature is raised to a first preset temperature (such as 1900°C-2000°C) under a first preset pressure (such as a high pressure of 40Kpa-80Kpa). The pressure of the second chamber 112 is raised to the same as that of the first chamber 111, and the temperature in the second chamber 112 is controlled within a second preset temperature range (such as 1900°C-2100°C). The conveying mechanism 170 starts depressurization growth after transferring the crucible 120 to the second chamber 112. The second chamber 112 can be quickly depressurized to a second preset pressure (such as 1Kpa-1.2Kpa) at a rate of 50Kpa / h-60Kpa / h. In the second chamber 112, it can be grown for a certain time at the second preset pressure. During the crystal growth stage, the temperature in the second chamber 112 can slowly increase to a third preset temperature (such as 2100°C-2400°C). In addition, the first chamber 111 needs to be cooled down. When there are 10 hours left before the crystal growth stage in the crucible 120 in the second chamber 112 ends, the first chamber 111 is opened and another crucible 120 is placed in to heat up. After the crystal growth stage in the crucible 120 in the second chamber 112 ends, the crucible 120 in the second chamber 112 is transferred to the third chamber 113. While the crucible in the second chamber 112 is transferred to the third chamber 113, another crucible 120 in the first chamber 111 is transferred to the second chamber 112 to continue growing. In the third chamber 113, the crucible 120 is annealed in situ. Specifically, in the third chamber 113, the pressure is increased to a third preset pressure (such as a high pressure of 40Kpa-80Kpa, for example), and the temperature is reduced at a certain cooling rate (such as 1°C / min to 3°C / min). After the in-situ annealing of the crucible 120 in the third chamber 113 is completed, the third chamber 113 is opened and the crucible 120 is taken out. The above method can realize the sequential circulation of the crucible 120.

[0072] 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.

[0073] 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.

[0074] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A crystal growth device, characterized in that: The device comprises a furnace body, a crucible and a heating component; wherein the furnace body comprises a furnace chamber, the crucible and the heating component are both arranged in the furnace chamber; the heating component heats the crucible; The furnace comprises a plurality of chambers, and there are a plurality of crucibles, and the plurality of crucibles are respectively arranged in the plurality of chambers; The crystal growth equipment also includes a conveying mechanism, at least part of which is located in the furnace, and the multiple chambers are arranged along a conveying direction of the conveying mechanism. The conveying mechanism conveys the multiple crucibles to move the multiple crucibles between different chambers.

2. The crystal growth device according to claim 1, characterized in that The multiple chambers form a first chamber, a second chamber and a third chamber; the first chamber, the second chamber and the third chamber are arranged along the conveying direction; the maximum temperature in the second chamber is higher than the maximum temperature in the first chamber, and the maximum temperature in the second chamber is higher than the maximum temperature in the third chamber; the maximum pressure in the second chamber is lower than the maximum pressure in the first chamber, and the maximum pressure in the second chamber is lower than the maximum pressure in the third chamber.

3. The crystal growth device according to claim 2, characterized in that: The crystal growth process includes a preheating stage, a crystal growth stage and an annealing stage. The crystal production in the crucible in the first chamber is in the preheating stage, the crystal production in the crucible in the second chamber is in the crystal growth stage, and the crystal production in the crucible in the third chamber is in the annealing stage.

4. The crystal growth device according to claim 1, characterized in that: A passage and an openable and closable partition are provided between two adjacent chambers.

5. The crystal growth apparatus according to claim 1, characterized in that The heating component includes at least one induction coil and at least one coil pulling device, at least one induction coil and at least one coil pulling device are arranged in at least one chamber, the coil pulling device is correspondingly connected to the induction coil, and the coil pulling device can pull the induction coil along the axial direction of the crucible.

6. The crystal growth apparatus according to claim 1, characterized in that The device also includes a plurality of heat-insulating structures, which are arranged one by one on the outside of the plurality of crucibles; the heat-insulating structure includes a side heat-insulating part and a top heat-insulating part, and the top heat-insulating part is provided with a temperature measuring port.

7. The crystal growth apparatus according to claim 1, characterized in that It also includes a temperature measuring mechanism, and the temperature measuring mechanism that can be extended into the temperature measuring port is telescopically arranged.

8. The crystal growth apparatus according to claim 1, characterized in that The crystal growth equipment includes a first temperature measuring component, which includes a first electrical rail and a plurality of first thermometers. The plurality of first thermometers respectively measure the temperature in the inner cavity of the plurality of crucibles. The first electrical rail is arranged outside the crucible, and a portion of each of the plurality of first thermometers that passes through the crucible is in sliding electrical contact with the first electrical rail. The first electrical rail is parallel to the conveying direction of the conveying mechanism.

9. The crystal growth apparatus according to claim 8, characterized in that A sealing structure is provided at the position on the crucible where the first thermometer passes through.

10. The crystal growth apparatus according to claim 1, characterized in that The crystal growth device further includes a plurality of resistance heaters, which are respectively disposed in the plurality of chambers and located at the bottom of the plurality of crucibles, and are disposed below the conveying mechanism in the axial direction of the crucible.

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