Device for growing multi-group single-furnace silicon carbide crystals by liquid phase method and its usage method

Abstract

The present invention belongs to the field of silicon carbide single crystal growth, and particularly relates to single crystal growth by the molten solution pulling method. More particularly, it relates to a device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method and its usage method. Among them, the device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method includes: a graphite crucible, a heating assembly, a driving mechanism, and a pulling and rotating mechanism; wherein, the graphite crucible includes: a crucible body and a separating ring; the separating ring is arranged in the crucible body and is used for separating the crucible body into a concentric inner groove and an outer groove. By resetting the structure of the graphite crucible, the crucible body is divided into an inner groove and an outer groove. The flux is placed in the outer groove, and the seed crystal is placed in the inner groove, thereby solving the problem in the related art that when the seed crystal is placed in the crucible, the flux will melt through the seed crystal, and further realizing the simultaneous growth of multiple groups of silicon carbide crystals in a single furnace, and reducing the growth cost of silicon carbide crystals.

Description

Technical Field

[0001] The present invention belongs to the field of silicon carbide single crystal growth, and specifically relates to single crystal growth by the molten liquid pulling method, and particularly relates to a device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method and a method for using the same. Background Art

[0002] The essence of growing silicon carbide crystals by the liquid phase method is to dissolve carbon solute in a graphite crucible by a flux. Driven by a temperature gradient, the solute reaches supersaturation at the seed crystal growth interface, and then silicon carbide crystals precipitate to achieve epitaxial growth of the crystals.

[0003] In related technologies, when growing silicon carbide crystals, only the single crystal growth method in a single furnace can be adopted, resulting in too high production costs of silicon carbide crystals. If multiple seeds are pulled simultaneously, it will lead to conflicts in the temperature gradients of the pulled seeds. The low-temperature regions of different seeds will overlap or squeeze each other, resulting in disordered temperature gradients and unbalanced solute distribution, affecting the crystal quality, such as the appearance of macroscopic steps. Therefore, the method of pulling multiple seeds simultaneously for crystal growth cannot be used to achieve the growth of multiple silicon carbide crystals in a single furnace. If the seed is directly placed at the bottom of the crucible, since the density of the flux is greater than that of silicon (Si), it will sink to the bottom in the molten liquid. During growth, the seed at the bottom of the crucible will contact the flux, resulting in the seed being melted through. Therefore, it is impossible to set the seed at the bottom of the crucible to achieve the growth of multiple groups of silicon carbide crystals in a single furnace.

[0004] Therefore, how to achieve the simultaneous growth of multiple groups of silicon carbide crystals in a single furnace to reduce the growth cost of silicon carbide crystals is a technical problem to be solved urgently at present.

[0005] It should be noted that the above information disclosed in this background art section is only used to understand the background art of the concept of this application. Therefore, it is not considered that the above description constitutes information of the prior art. Summary of the Invention

[0006] The embodiments of the present disclosure at least provide a device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method and a method for using the same.

[0007] In a first aspect, the embodiments of the present disclosure provide a device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method, including:

[0008] A graphite crucible for containing raw materials;

[0009] A heating assembly disposed around the graphite crucible and used for heating the raw materials in the crucible;

[0010] A driving mechanism disposed below the graphite crucible and used for driving the graphite crucible to rotate;

[0011] A lifting and rotating mechanism is provided above the graphite crucible, and its bottom is used to place a seed crystal for crystal growth;

[0012] Wherein, the graphite crucible includes:

[0013] A crucible body and a separating ring;

[0014] The separating ring is arranged inside the crucible body and is used to divide the crucible body into a concentric inner groove and an outer groove;

[0015] The inner groove is used to place the Si blocks in the raw materials; the outer groove is used to place the flux;

[0016] An installation groove is provided at the bottom of the inner groove;

[0017] During crystal growth, the seed crystal is placed in the installation groove and at the bottom of the lifting and rotating mechanism respectively, and multiple silicon carbide crystals are grown simultaneously.

[0018] In an optional embodiment, the height of the crucible body is H1;

[0019] The height of the separating ring is H2;

[0020] Wherein, H1 > H2, and the units of H1 and H2 are mm.

[0021] In an optional embodiment, the radius of the inner groove is R1;

[0022] The radius of the outer groove is R2;

[0023] Wherein, 1.5R1 < R2 < 2R1, and the units of R1 and R2 are mm.

[0024] In an optional embodiment, the depth of the installation groove is h;

[0025] Wherein, h < L, where L is the thickness of the seed crystal;

[0026] Moreover, the range of h is between 0.5 mm and 1 mm.

[0027] In an optional embodiment, the bottom height of the inner groove is higher than the bottom height of the outer groove;

[0028] When the driving mechanism drives the graphite crucible to rotate, the separating ring blocks the flux from entering the inner groove.

[0029] In an optional embodiment, a plurality of stirring rods are further provided in the outer groove of the graphite crucible;

[0030] The plurality of stirring rods are arranged along the circumferential direction of the outer groove and are connected to the bottom of the outer groove;

[0031] When the driving mechanism drives the graphite crucible to rotate, the molten liquid in the outer groove is stirred by the stirring rod.

[0032] In an alternative embodiment, the stirring rods include multiple groups;

[0033] The number of stirring rods in each group of the stirring rods is two;

[0034] A diversion inclined plate is arranged between the two stirring rods in each group of the stirring rods;

[0035] Moreover, the diversion direction of the diversion inclined plate is opposite to the rotation direction of the graphite crucible.

[0036] In an alternative embodiment, the diversion inclined plate includes a first arc-shaped plate and a second arc-shaped plate;

[0037] The outer arc side of the second arc-shaped plate is connected to the inner arc side of the first arc-shaped plate;

[0038] Moreover, the second arc-shaped plate is arranged to incline downward, so as to guide the flux downward when the driving mechanism drives the graphite crucible to rotate, thereby facilitating the stratification of the melted carbon and the flux.

[0039] In an alternative embodiment, the bottom of the diversion inclined plate is lower than the bottom of the inner groove;

[0040] Moreover, the top of the diversion inclined plate is lower than the top of the partition ring.

[0041] In an alternative embodiment, the stirring rod is threadedly connected to the bottom of the outer groove;

[0042] Lap blocks are respectively arranged on the two stirring rods in each group of the stirring rods;

[0043] A lap groove is formed in the side wall of one of the lap blocks;

[0044] One end of the diversion inclined plate is inserted into the lap groove, the other end is lapped with the other lap block, and the outer side wall of the diversion inclined plate abuts against the side wall of the outer groove;

[0045] When it is necessary to adjust the inclination angle a of the diversion inclined plate, the corresponding stirring rod is screwed to adjust the height of the lap block, so as to complete the adjustment of the inclination angle of the diversion inclined plate.

[0046] In a second aspect, the embodiments of the present disclosure further provide a usage method of a device applied to the device for growing single-furnace multi-group silicon carbide crystals by the liquid phase method as described above, and the usage method includes:

[0047] Seed crystals are respectively bonded to the bottom of the lifting and rotating mechanism and in the installation groove;

[0048] Place the Si block in the inner groove of the graphite crucible and place the flux in the outer groove;

[0049] Control the heating component to heat the graphite crucible until the flux is completely melted to obtain a melt;

[0050] Control the driving mechanism to drive the graphite crucible to rotate;

[0051] Adjust the position of the high-temperature wire of the heating component so that the high-temperature wire reaches the middle of the molten liquid in the inner groove;

[0052] Control the lifting and rotating mechanism to make the seed crystal at the bottom of the lifting and rotating mechanism contact the molten liquid, and continuously rotate and lift it so that the seed crystal bonded to the bottom of the lifting and rotating mechanism and in the installation groove grows crystals simultaneously.

[0053] The beneficial effect of the present invention is that the device for growing single-furnace and multi-group silicon carbide crystals by the liquid phase method re-sets the structure of the graphite crucible, divides the crucible body into an inner groove and an outer groove, places the flux in the outer groove, and places the seed crystal in the inner groove, thus solving the problem in the related technology that when the seed crystal is placed in the crucible, the flux will melt through the seed crystal, and further realizing the simultaneous growth of single-furnace and multi-group silicon carbide crystals, reducing the growth cost of silicon carbide crystals.

[0054] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the specification and the drawings.

[0055] To make the above objectives, features, and advantages of the present invention more obvious and understandable, specific preferred embodiments are hereby given, and in conjunction with the accompanying drawings, the following detailed description is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0057] Figure 1 The device for growing single-furnace and multi-group silicon carbide crystals provided by the embodiments of the present disclosure;

[0058] Figure 2 The structural schematic diagram of the graphite crucible provided by the embodiments of the present disclosure;

[0059] Figure 3A cross-sectional view of the graphite crucible provided by an embodiment of the present disclosure;

[0060] Figure 4 A cross-sectional view of the graphite crucible provided by an embodiment of the present disclosure from another perspective;

[0061] Figure 5 A schematic structural diagram of the diversion inclined plate provided by an embodiment of the present disclosure;

[0062] Figure 6 A flowchart of the usage method for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method provided by an embodiment of the present disclosure;

[0063] Figure 7 A schematic diagram of the overlap of one set of stirring rods and the diversion inclined plate in the graphite crucible provided by an embodiment of the present disclosure.

[0064] In the figure: 100, graphite crucible; 110, crucible body; 120, partition ring; 130, inner groove; 131, installation groove; 140, outer groove; 141, stirring rod; 141a, overlapping block; 141b, overlapping groove; 142, diversion inclined plate; 142a, first arc plate; 142b, second arc plate; 200, heating assembly; 300, driving mechanism; 400, lifting and rotating mechanism; 500, seed crystal. Detailed implementation manners

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0066] After research, it is found that for the two growth methods of multiple groups of seed crystals in a single furnace in the related art, the first one is to lift multiple seed crystals simultaneously, which will lead to temperature gradient conflicts in the lifted and grown seed crystals. The low-temperature regions of different seed crystals will overlap or squeeze each other, resulting in temperature gradient disorder and solute distribution imbalance. There are obvious macroscopic steps in the multiple silicon carbide crystals generated, which cannot meet the usage requirements; the second one is to place the seed crystal at the bottom of the crucible, which will cause the seed crystal to be melted through by the flux, and silicon carbide crystals cannot be obtained.

[0067] Based on the above research, embodiments of the present disclosure provide an apparatus for growing multiple groups of silicon carbide crystals in a single furnace by liquid phase method and its usage method. By improving the structure of the crucible, the graphite crucible 100 is divided into two grooves, and the flux and the seed crystal 500 are placed in different grooves simultaneously. Without affecting the growth of the seed crystal 500 at the bottom of the lifting and rotating mechanism 400, multiple silicon carbide crystals can be generated. After the silicon carbide crystals grown from the seed crystal 500 in the crucible are appropriately cut, they can meet the usage requirements, thereby realizing the simultaneous growth of multiple groups of silicon carbide crystals in a single furnace.

[0068] Regarding the defects existing in the above solutions, they are all the results obtained by the inventors through practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed by the present disclosure in this article for the above problems should all be the contributions made by the inventors to the present disclosure during the process of the present disclosure.

[0069] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0070] The following will describe in detail some embodiments of the present invention with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0071] Please refer to Figure 1 and Figure 2 , at least one embodiment provides an apparatus for growing multiple groups of silicon carbide crystals in a single furnace by liquid phase method, including the following structures:

[0072] A graphite crucible 100, which is used to hold raw materials. Through the flux in the raw materials, the graphite of the graphite crucible 100 is dissolved to provide carbon (C) to the molten liquid.

[0073] Among them, the flux is one or more of Cr, Al, Sc, Co, Ti, Fe, Sn.

[0074] A heating assembly 200, which is arranged around the graphite crucible 100 and is used to heat the raw materials in the crucible.

[0075] Among them, the heating assembly 200 includes a heat insulation layer, a heating coil, and a lifting mechanism; the heat insulation layer 210 is wrapped around the graphite crucible 100; the heating coil is wrapped around the heat insulation layer and is used to heat the graphite crucible 100, and the middle part of the heating coil is the place with the highest heat, that is, the high-temperature wire of the heating assembly 200 is located in the middle of the heating coil; the lifting mechanism is used to drive the heating coil to expand and contract, and the lifting speed of the lifting mechanism is the same as the lifting speed of the lifting and rotating mechanism 400.

[0076] Among them, the lifting mechanism can adopt the method of using a lifting cylinder or a push rod motor to push the lifting plate to lift the heating coil, so as to change the position of the high-temperature wire of the heating coil.

[0077] The driving mechanism 300 is arranged below the graphite crucible 100 and is used to drive the graphite crucible 100 to rotate. Among them, the driving mechanism 300 can adopt the method of cooperating a rotating motor with a rotating table to realize the rotation of the graphite crucible 100.

[0078] The lifting and rotating mechanism 400 is arranged above the graphite crucible 100, and its bottom is used to place the seed crystal 500 for crystal growth.

[0079] Among them, the structure of the lifting and rotating mechanism 400 is prior art. Specifically, a linkage structure of a lifting cylinder cooperating with a rotating motor can be adopted to realize rotation and lifting.

[0080] Please continue to refer to Figure 1 and 2 , where the graphite crucible 100 includes: a crucible body 110 and a separating ring 120; the separating ring 120 is arranged in the crucible body 110 and is used to divide the crucible body 110 into a concentric inner groove 130 and an outer groove 140; the inner groove 130 is used to place the Si blocks in the raw materials; the outer groove 140 is used to place the flux; an installation groove 131 is arranged at the bottom of the inner groove 130; during crystal growth, the seed crystal 500 is respectively placed in the installation groove 131 and the bottom of the lifting and rotating mechanism 400, and multiple silicon carbide crystals are grown simultaneously.

[0081] By resetting the structure of the graphite crucible 100, the crucible body 110 is divided into an inner groove 130 and an outer groove 140, the flux is placed in the outer groove 140, and the seed crystal 500 is placed in the inner groove 130, thereby solving the problem in the related art that when the seed crystal 500 is placed in the crucible, the flux will melt through the seed crystal 500, and further realizing the simultaneous growth of multiple groups of silicon carbide crystals in a single furnace, and reducing the growth cost of silicon carbide crystals.

[0082] Please refer to Figure 3 , the height of the crucible body 110 is H1; the height of the separating ring 120 is H2; among them, H1 > H2, and the units of H1 and H2 are mm. Since the height H2 of the separating ring 120 is lower than the height H1 of the crucible body 110, the melted carbon enters the inner groove 130 for crystal growth.

[0083] Among them, the radius of the inner groove 130 is R1; the radius of the outer groove 140 is R2; where 1.5R1 < R2 < 2R1, and the units of R1 and R2 are mm. By reasonably setting the sizes of R1 and R2, the carbon dissolution rate is restricted so that the carbon dissolution rate meets the growth requirements of multiple seeds 500.

[0084] It should be noted that the depth of the installation groove 131 is h; where h < L, where L is the thickness of the seed 500; and the range of h is between 0.5 mm and 1 mm. The thickness of the seed 500 is higher than the depth of the installation groove 131, which facilitates crystal growth on the surface of the seed 500.

[0085] In a preferred embodiment, the bottom height of the inner groove 130 is higher than the bottom height of the outer groove 140; when the driving mechanism 300 drives the graphite crucible 100 to rotate, the partition ring blocks the flux from entering the inner groove 130. By deepening the groove depth of the outer groove 140, the liquid level height of the molten flux is reduced, thereby reducing the amount of flux entering the inner groove 130 during rotation and further preventing the seed 500 from being melted through.

[0086] Please refer to Figures 2 to 4 , a plurality of stirring rods 141 are further provided in the outer groove 140 of the graphite crucible 100; the plurality of stirring rods 141 are arranged along the circumferential direction of the outer groove 140 and are connected to the bottom of the outer groove 140; when the driving mechanism 300 drives the graphite crucible 100 to rotate, the molten liquid in the outer groove 140 is stirred by the stirring rods 141. Through the stirring rods 141, the stratification of the flux and the molten carbon is accelerated. Since the density of the flux is relatively large, it will gradually sink to the bottom during stirring, and the molten carbon will be located above the molten liquid, facilitating the growth of silicon carbide.

[0087] In order to accelerate the sinking of the flux, the stirring rods 141 include multiple groups; the number of stirring rods 141 in each group of stirring rods 141 is two; a diversion inclined plate 142 is arranged between the two stirring rods 141 in each group of stirring rods 141; and the diversion direction of the diversion inclined plate 142 is opposite to the rotation direction of the graphite crucible 100.

[0088] The molten liquid at the lower part of the outer groove 140 is lifted by the diversion inclined plate 142 to promote the stratification of the flux and the melted carbon.

[0089] Among them, the rotation direction of the graphite crucible 100 is as shown by F1 in Figure 2 , and the diversion direction of the diversion inclined plate 142 is as shown by F2 in Figure 2 .

[0090] Please refer to Figure 5, the diversion inclined plate 142 includes a first arc plate 142a and a second arc plate 142b; the outer arc side of the second arc plate 142b is connected to the inner arc side of the first arc plate 142a; and, the second arc plate 142b is inclined downward, so as to guide the flux downward when the driving mechanism 300 drives the graphite crucible 100 to rotate, thereby facilitating the stratification of the melted carbon and the flux.

[0091] Please refer to Figure 3 , the bottom of the diversion inclined plate 142 is lower than the bottom of the inner groove 130; and, the top of the diversion inclined plate 142 is lower than the top of the separation ring 120. By limiting the position of the diversion inclined plate 142, the flux is prevented from being introduced into the inner groove 130 by the diversion inclined plate 142, and the amount of flux entering the inner groove 130 is reduced.

[0092] Please refer to Figure 3 and Figure 7 , in order to adapt to the pulling growth requirements of different sizes of seed crystals 500, the stirring rod 141 is threadedly connected to the bottom of the outer groove 140; lap joints 141a are respectively arranged on two stirring rods 141 in each group of stirring rods 141; a lap joint groove 141b is formed in the side wall of one of the lap joints 141a; one end of the diversion inclined plate 142 is inserted into the lap joint groove 141b, and the other end is lapped with the other lap joint 141a, and the outer side wall of the diversion inclined plate 142 abuts against the side wall of the outer groove 140; when the inclination angle a of the diversion inclined plate 142 needs to be adjusted, the corresponding stirring rod 141 is screwed to adjust the height of the lap joint 141a, so as to complete the adjustment of the inclination angle a of the diversion inclined plate 142.

[0093] By adjusting the inclination angle a of the diversion inclined plate 142, the content of carbon entering the inner groove 130 is adjusted, so as to meet the pulling growth requirements of different sizes of seed crystals 500.

[0094] Among them, the range of a is between 15° and 50°.

[0095] Please refer to Figure 6 , at least one embodiment further provides a use method of an apparatus for growing single furnace and multiple groups of silicon carbide crystals by a liquid phase method as described above, and the use method includes:

[0096] Step S1, bonding the seed crystal 500 to the bottom of the lifting and rotating mechanism 400 and in the installation groove 131 respectively;

[0097] Step S2, placing the Si block in the inner groove 130 of the graphite crucible 100, and placing the flux in the outer groove 140;

[0098] Step S3: Control the heating component 200 to heat the graphite crucible 100 until the flux is completely melted to obtain a melt.

[0099] Step S4: Control the driving mechanism 300 to drive the graphite crucible 100 to rotate.

[0100] Step S5: Adjust the position of the high-temperature wire of the heating component 200 so that the high-temperature wire reaches the middle of the molten liquid in the inner groove.

[0101] Step S6: Control the lifting and rotating mechanism 400 to make the seed crystal 500 at the bottom of the lifting and rotating mechanism 400 contact the molten liquid, and continuously rotate and lift, so that the seed crystal 500 bonded at the bottom of the lifting and rotating mechanism and in the mounting groove 131 grows crystals simultaneously.

[0102] Example 1: Grow multiple groups of silicon carbide crystals according to the above device for growing multiple groups of silicon carbide crystals by the liquid phase method and its usage method.

[0103] The steps are as follows:

[0104] Step 1: Bond a 6-inch seed crystal 500 to the bottom of the seed crystal rod of the lifting and rotating mechanism 400, and bond 3 pieces of 2-inch seed crystals 500 to the mounting groove 131 at the center bottom of the graphite crucible 100.

[0105] Step 2: After assembling the experimental device, close the furnace chamber, perform vacuum pumping, then fill the furnace chamber with inert gas, place the Si block above the 2-inch seed crystal 500 in the inner groove 130 of the graphite crucible 100, place the Cr block in the outer groove 140 of the graphite crucible 100, and heat the raw materials until they are completely melted.

[0106] Step 3: Rotate the graphite crucible 100 at a speed of 15 rpm.

[0107] Step 4: Move the heating coil of the heating component 200 and adjust the high-temperature wire to the middle of the molten liquid in the inner groove.

[0108] Step 5: Lower the seed crystal rod 500, and start rotating and lifting the 6-inch seed crystal 500 for growth after it contacts the liquid surface at 30 rpm.

[0109] Finally, there are a small number of steps distributed on the surface of the grown 6-inch silicon carbide single crystal, but there is no solvent inclusion; the 3 pieces of 2-inch silicon carbide crystals at the bottom are obtained after appropriate cutting, the growth surface is effectively remelted, and the whole is a single crystal without solvent inclusion, meeting the usage requirements.

[0110] Example 2: Grow multiple groups of silicon carbide crystals according to the above device for growing multiple groups of silicon carbide crystals by the liquid phase method and its usage method.

[0111] Step 1: Bond a 6-inch seed crystal 500 to the bottom of the seed crystal rod of the lifting and rotating mechanism 400, and bond three 2-inch seed crystals 500 to the mounting groove 131 at the center bottom of the graphite crucible 100.

[0112] Step 2: After assembling the experimental device, close the furnace chamber, perform a vacuum pumping process, and then fill the furnace chamber with an inert gas. Place the Si block above the 2-inch seed crystal 500 in the inner groove 130 of the graphite crucible 100, and place the Cr block and Al block in the outer groove 140 of the graphite crucible 100, and heat the raw materials until they are completely melted.

[0113] Step 3: Rotate the graphite crucible 100 at a speed of 15 rpm.

[0114] Step 4: Move the heating coil of the heating assembly 200 and adjust the high-temperature wire to the middle of the molten liquid in the inner groove.

[0115] Step 5: Lower the seed crystal rod 500. After the 6-inch seed crystal 500 touches the liquid surface, start rotating and pulling to grow at 30 rpm.

[0116] Finally, the surface of the 6-inch single-crystal silicon carbide obtained by growth is smooth, without obvious macroscopic steps. The three 2-inch silicon carbide crystals at the bottom are obtained after appropriate cutting. The growth surface is effectively remelted, and the whole is a single crystal without solvent inclusions.

[0117] Through Example 1 and Example 2, the effectiveness of the device and its use method for growing multiple groups of silicon carbide crystals in a single furnace by the liquid-phase method for growing multiple groups of silicon carbide crystals was verified.

[0118] Comparative Example 1: The experimental steps are basically the same as those in Example 2, except that the rotation speed of the graphite crucible 100 is 20 rpm.

[0119] Finally, before the seed crystal rod 500 touches the liquid surface, a large number of floating silicon carbide crystals float on the liquid surface. Finally, a large number of polycrystalline attachments exist in the 6-inch silicon carbide crystal obtained by growth. The 2-inch silicon carbide crystal at the bottom is obtained after appropriate cutting. The growth surface is effectively remelted, and the whole is a single crystal without solvent inclusions. This phenomenon shows that when the graphite crucible rotates at 20 rpm, the heat dissipation of the liquid surface increases, increasing the risk of silicon carbide grains appearing on the free liquid surface, but having little effect on the growth of the bottom crystal.

[0120] Comparative Example 2: The experimental steps are basically the same as those in Example 2, except that the placement position of the raw materials in the graphite crucible 100 is different.

[0121] In Comparative Example 2, the Si block and the Cr block are evenly mixed in advance and placed in the inner and outer rings of the crucible.

[0122] As a result, during the chemical material addition process, due to the large density of Cr, it sank to the bottom center of the crucible, causing the bottom seed crystal 500 to melt through, and it was impossible to grow multiple groups of silicon carbide crystals simultaneously in a single furnace.

[0123] Comparative Example 3: The experimental steps were basically the same as those in Example 2, except that the high-temperature wire was placed at the bottom of the graphite crucible 100.

[0124] As a result, the surface of the grown 6-inch silicon carbide single crystal was smooth, without obvious macroscopic steps, and the bottom three 2-inch silicon carbide crystals were completely dissolved under the action of high temperature.

[0125] From the above Examples 1 and 2 and Comparative Examples 1 - 3, it can be concluded that the device and its use method for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method can place the seed crystal 500 in the graphite crucible 100 to grow multiple silicon carbide crystals simultaneously, and it will not affect the crystal growth of the seed crystal 500 lifted by the lifting and rotating mechanism 400.

[0126] The beneficial effects of the present invention are as follows: The present invention provides a device and its use method for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method. Among them, the device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method includes: a graphite crucible 100, which is used to hold raw materials; a heating component 200, which is arranged around the graphite crucible 100 and is used to heat the raw materials in the crucible; a driving mechanism 300, which is arranged below the graphite crucible 100 and is used to drive the graphite crucible 100 to rotate; a lifting and rotating mechanism 400, which is arranged above the graphite crucible 100, and its bottom is used to place the seed crystal 500 for crystal growth; among them, the graphite crucible 100 includes: a crucible body 110 and a partition ring 120; the partition ring 120 is arranged in the crucible body 110 and is used to divide the crucible body 110 into a concentric inner groove 130 and an outer groove 140; the inner groove 130 is used to place Si blocks in the raw materials; the outer groove 140 is used to place a flux; an installation groove 131 is arranged at the bottom of the inner groove 130; during crystal growth, the seed crystal 500 is placed in the installation groove 131 and at the bottom of the lifting and rotating mechanism 400 respectively to grow multiple silicon carbide crystals simultaneously. By re-setting the structure of the graphite crucible 100, the crucible body 110 is divided into an inner groove 130 and an outer groove 140, the flux is placed in the outer groove 140, and the seed crystal 500 is placed in the inner groove 130, thus solving the problem in the related art that when the seed crystal 500 is placed in the crucible, the flux will melt through the seed crystal 500, and further realizing the simultaneous growth of multiple groups of silicon carbide crystals in a single furnace and reducing the growth cost of silicon carbide crystals.

[0127] Inspired by the above-described ideal embodiments of the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An apparatus for growing multiple groups of single furnace silicon carbide crystals by liquid phase method, characterized in that, Comprising: A graphite crucible (100) for containing raw materials; A heating assembly (200) disposed around the graphite crucible (100) and used for heating the raw materials in the crucible; A driving mechanism (300) disposed below the graphite crucible (100) and used for driving the graphite crucible (100) to rotate; A lifting and rotating mechanism (400) disposed above the graphite crucible (100), and its bottom is used for placing a seed crystal (500) for crystal growth; Wherein, the graphite crucible (100) comprises: A crucible body (110) and a separating ring (120); The separating ring (120) is disposed inside the crucible body (110) and used for separating the crucible body (110) into a concentric inner groove (130) and an outer groove (140); The inner groove (130) is used for placing Si blocks in the raw materials; the outer groove (140) is used for placing a flux; The bottom of the inner groove (130) is provided with a mounting groove (131); During crystal growth, the seed crystal (500) is respectively placed in the mounting groove (131) and the bottom of the lifting and rotating mechanism (400), and multiple silicon carbide crystals are grown simultaneously.

2. The apparatus for growing multi-group single-furnace silicon carbide crystals by the liquid phase method according to claim 1, characterized in that, The height of the crucible body (110) is H1; The height of the separating ring (120) is H2; Wherein, H1 > H2, and the units of H1 and H2 are mm.

3. The apparatus for growing multi-group single-furnace silicon carbide crystals by the liquid phase method according to claim 1, characterized in that, The radius of the inner groove (130) is R1; The radius of the outer groove (140) is R2; Wherein, 1.5R1 < R2 < 2R1, and the units of R1 and R2 are mm.

4. The apparatus for growing multiple groups of single furnace silicon carbide crystals by liquid phase method according to claim 1, wherein, The depth of the mounting groove (131) is h; Wherein, h < L, where L is the thickness of the seed crystal (500); And the range of h is between 0.5 mm and 1 mm.

5. The apparatus for growing multi-group single-furnace silicon carbide crystals by the liquid phase method according to claim 1, characterized in that, The bottom height of the inner groove (130) is higher than the bottom height of the outer groove (140); When the driving mechanism (300) drives the graphite crucible (100) to rotate, the separating ring blocks the flux from entering the inner groove (130).

6. The device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method according to claim 5, characterized in that The outer groove (140) of the graphite crucible (100) is further provided with a plurality of stirring rods (141); The plurality of stirring rods (141) are arranged along the circumferential direction of the outer groove (140) and are connected to the bottom of the outer groove (140); When the driving mechanism (300) drives the graphite crucible (100) to rotate, the molten liquid in the outer groove (140) is stirred by the stirring rods (141).

7. The device for growing multiple groups of silicon carbide crystals in a single furnace by the liquid phase method according to claim 6, characterized in that The stirring rods (141) include multiple groups; The number of stirring rods (141) in each group of the stirring rods (141) is two; A flow guiding inclined plate (142) is arranged between the two stirring rods (141) in each group of the stirring rods (141); And the flow guiding direction of the flow guiding inclined plate (142) is opposite to the rotation direction of the graphite crucible (100).

8. The device for growing multiple groups of single-furnace silicon carbide crystals by liquid phase method according to claim 7, characterized in that the diversion inclined plate (142) includes a first arc plate (142a) and a second arc plate (142b); the outer arc side of the second arc plate (142b) is connected to the inner arc side of the first arc plate (142a); moreover, the second arc plate (142b) is arranged obliquely downward, so that when the driving mechanism (300) drives the graphite crucible (100) to rotate, the flux is guided downward, thereby facilitating the stratification of the melted carbon and the flux.

9. The device for growing multiple groups of single-furnace silicon carbide crystals by liquid phase method according to claim 7, characterized in that the bottom of the diversion inclined plate (142) is lower than the bottom of the inner groove (130); moreover, the top of the diversion inclined plate (142) is lower than the top of the partition ring (120).

10. The device for growing multiple groups of single-furnace silicon carbide crystals by liquid phase method according to claim 7, characterized in that the stirring rod (141) is threadedly connected to the bottom of the outer groove (140); lap blocks (141a) are respectively arranged on two stirring rods (141) in each group of stirring rods (141); a lap groove (141b) is formed on the side wall of one of the lap blocks (141a); one end of the diversion inclined plate (142) is inserted into the lap groove (141b), and the other end is lapped with the other lap block (141a), and the outer side wall of the diversion inclined plate (142) abuts against the side wall of the outer groove (140); when it is necessary to adjust the inclination angle a of the diversion inclined plate (142), by screwing the corresponding stirring rod (141), the height of the lap block (141a) is adjusted to complete the adjustment of the inclination angle of the diversion inclined plate (142).

11. A method of using an apparatus for growing single-furnace multi-group silicon carbide crystals by a liquid-phase method as described in claim 1, characterized in that, The usage method includes: adhering seed crystals (500) to the bottom of the lifting and rotating mechanism (400) and in the installation groove (131) respectively; placing Si blocks in the inner groove (130) of the graphite crucible (100), and placing the flux in the outer groove (140); controlling the heating component (200) to heat the graphite crucible (100) until the flux is completely melted to obtain a melt; controlling the driving mechanism (300) to drive the graphite crucible (100) to rotate; adjusting the position of the high-temperature wire of the heating component (200) to make the high-temperature wire reach the middle of the molten liquid in the inner groove; controlling the lifting and rotating mechanism (400) to make the seed crystal (500) at the bottom of the lifting and rotating mechanism (400) contact the molten liquid, and continuously rotating and lifting, so that the seed crystals (500) adhered to the bottom of the lifting and rotating mechanism (400) and in the installation groove (131) grow crystals simultaneously.

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