Filtering-diversion module, crystal growth device and crystal growth method

Abstract

The invention relates to the technical field of crystal growth, and discloses a filtering-flow guiding module, a crystal growth device and a crystal growth method.The filtering-flow guiding module comprises an outer shell, an inner shell and a flow guiding device, the inner shell is arranged in the containing space, a conveying channel is defined in the inner shell, the inner shell sequentially comprises a first section, a second section and a third section from top to bottom, and the first section, the second section and the third section are connected to the outer shell in an independent rotating mode. When the crystal growth device and the crystal growth method are used for crystal growth, the crystal growth speed and the crystal growth quality can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of crystal growth technology, and in particular to a filtration-guiding module, a crystal growth device and a crystal growth method. Background Art

[0002] Physical vapor transport (PVT) has become the mainstream method for growing crystals. Currently, the more mature crystal growth process takes about 12 days or even longer, which is not conducive to mass production. Furthermore, during the crystal production process, some carbon and silicon particles are easily introduced into the crystal, resulting in inclusions and affecting the crystal quality. Therefore, developing a crystal growth device that can effectively improve crystal growth efficiency and quality is one of the current challenges.

[0003] Application Contents

[0004] This application aims to at least partially address one of the technical problems in the related art. To this end, one objective of this application is to provide a filtration-flow guide module, a crystal growth device, and a crystal growth method. Using the crystal growth device and crystal growth method of this application for crystal growth can effectively improve crystal growth efficiency, shorten crystal growth time, and significantly enhance crystal quality.

[0005] In a first aspect of the present application, a filtration-flow guide module for a crystal growth device is provided, comprising:

[0006] An outer shell defines a receiving space therein;

[0007] An inner shell is arranged in the accommodating space, and a transmission channel is defined inside the inner shell. The inner shell includes a first section, a second section and a third section from top to bottom, and the first section, the second section and the third section are independently rotatably connected to the outer shell.

[0008] The filter-diversion module has a three-stage design, and all three stages can rotate independently. By adjusting the rotational speed of the first, second, and third stages of the inner shell, a positive pressure difference from bottom to top is generated in the transmission channel. As a result, when the crystal growth raw materials sublime, the positive pressure difference generated in the transmission channel can increase the sublimation speed of the crystal growth raw materials, thereby greatly improving the crystal growth efficiency.

[0009] In addition, the filter-flow guide module according to the above embodiment of the present application may also have the following additional technical features:

[0010] In some embodiments, the radial dimension of the transmission channel gradually decreases from bottom to top. Therefore, according to the core laws of fluid mechanics, the different radial dimensions of the first, second, and third sections of the transmission channel, which gradually decrease from bottom to top, also generate a positive pressure difference from bottom to top, thereby further increasing the crystal growth rate.

[0011] In some embodiments, the radial dimension of the transmission channel is R1 ≥ R2 ≥ R1 / 2, wherein R1 is the radial dimension of the lowest end of the transmission channel, and R2 is the radial dimension of the highest end of the transmission channel. Thus, a positive pressure difference is generated in the transmission channel from bottom to top.

[0012] In some embodiments, the inner shell has a hollow pattern on its sidewall, and a gap is formed between the inner shell and the outer shell, thereby facilitating the filtration and removal of particles carried by the crystal growth raw materials during the crystal growth process, thereby improving the quality of the crystal growth.

[0013] In some embodiments, the hollow pattern satisfies at least one of the following conditions:

[0014] The hollow pattern includes spiral openings.

[0015] The dimension F of the hollow pattern in the direction perpendicular to the radial dimension of the transmission channel and the radial dimension R1 of the transmission channel satisfy F=R1 / 20~R1 / 5;

[0016] Wherein, R1 is the radial dimension of the lowermost end of the transmission channel.

[0017] In this way, it is possible to ensure that particles in the crystal growth raw material are filtered out without affecting the transmission of the crystal growth raw material.

[0018] In some embodiments, the filter-flow guide module further includes at least one of the following:

[0019] An air intake assembly, disposed below the transmission channel, for allowing the raw gas to enter the filter-guiding module;

[0020] The gas outlet assembly is arranged above the transmission channel and is used to output the raw material gas to the filtering and guiding module, thereby helping to further improve the transmission speed of the crystal growth raw material during sublimation and shorten the crystal growth time.

[0021] In some embodiments, the air inlet assembly and the air outlet assembly each independently include a blower, thereby promoting the raw gas to enter the transmission channel or exit the transmission channel through the operation of the blower.

[0022] In a second aspect of the present application, a crystal growth device is proposed, comprising the aforementioned filtration-guiding module.

[0023] In some embodiments, the crystal growth apparatus further comprises:

[0024] Crucible, used to hold crystal growth raw materials;

[0025] A graphite cover that can move up and down is arranged on the crucible, and the filtering and guiding module is arranged on the inner wall of the graphite cover. Therefore, using the crystal growth device for crystal growth can effectively improve the crystal growth efficiency and improve the crystal quality.

[0026] In some embodiments, the crucible has a first thread on its upper edge and a second thread on its lower edge, wherein the first thread and the second thread match. Connecting the graphite cover and crucible via the threads simplifies installation and further enhances the flexibility of the crystal growth apparatus.

[0027] In some embodiments, a movable height H is reserved between the first thread and the second thread;

[0028] The movable height refers to the height of a non-contact region between the first thread and the second thread.

[0029] Thus, the matching height between the first thread and the second thread can be flexibly adjusted according to the crystal growth time.

[0030] In some embodiments, the crystal growth apparatus further comprises:

[0031] A rotating shaft is arranged above the graphite cover;

[0032] A drive assembly is connected to the rotating shaft and is used to drive the graphite cover to rotate via the rotating shaft. Thus, the graphite cover can be rotated during the crystal growth process to maintain a fixed distance between the crystal growth feedstock and the seed crystal, thereby further improving the quality of the crystal.

[0033] In some embodiments, the crystal growth apparatus further comprises a base, and the crucible is fixedly connected to the base, thereby improving the stability of the crystal growth apparatus.

[0034] In a third aspect of the present application, a method for crystal growth using the aforementioned crystal growth apparatus is provided, comprising: continuously rotating the first, second, and third sections of the transmission channel during the crystal growth process. This generates a positive pressure differential from bottom to top in the transmission channel during the crystal growth process, accelerating the transfer of feedstock gas and improving crystal growth efficiency.

[0035] In some embodiments, the crystal growth method satisfies any one of the following conditions:

[0036] The first section, the second section and the third section rotate at speeds of V3, V4 and V5 respectively, and V3>V4>V5;

[0037] The radial dimension of the transmission channel gradually decreases from bottom to top, and the first section, the second section and the third section rotate at the same speed. Thus, any of the above methods can achieve an increase in crystal growth rate.

[0038] In some embodiments, the filter-guiding module in the crystal growth apparatus includes an air inlet assembly and an air outlet assembly, and satisfies at least one of the following conditions:

[0039] V2>V3>V4>V5>V1;

[0040] 50rpm≥V2-V1≥5rpm;

[0041] V1=1rpm~100rpm;

[0042] V2 = 10 rpm ~ 150 rpm;

[0043] Wherein, V1 is the rotation speed of the air inlet component of the crystal growth device, and V2 is the rotation speed of the air outlet component of the crystal growth device. This helps to further improve the crystal growth speed.

[0044] In some embodiments, during the crystal growth process, the height of the graphite cap is continuously decreased to maintain a constant distance between the upper surface of the crystal growth feedstock and the lower surface of the growing crystal, thereby helping to increase the crystal growth rate and improve the crystal quality.

[0045] In some embodiments, the graphite cover is continuously rotated along a thread matched with the crucible so that its height is continuously decreased, and the rotation speed P of the graphite cover is 0.01 rpm to 1 rpm. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a structural diagram of a filtering-guiding device according to an embodiment of the present application.

[0047] Figure 2 It is a structural schematic diagram of a filtering-guiding device according to an embodiment of the present application.

[0048] Figure 3 It is a structural schematic diagram of a crystal growth device according to an embodiment of the present application.

[0049] Figure 4 It is a structural schematic diagram of a crystal growth device in the related art.

[0050] Figure 5 This is the result of slice dislocation of the crystal of one embodiment of the present application.

[0051] Figure 6 This is the result of slice dislocation of the crystal of one embodiment of the present application.

[0052] Figure 7 This is the result of slice dislocation of a crystal in a comparative example of the present application.

[0053] Possession Mark:

[0054] 1: Outer shell 2: Inner shell 3: Transmission channel 4: Intake assembly

[0055] 5: Gas outlet assembly 6: Filter-flow guide module 7: Crucible 8: Graphite cover

[0056] 9: Rotating shaft 10: Driving assembly 11: Base 12: Seed crystal 13: Crystal growth material 2-1: First section of inner shell 2-2: Second section of inner shell 2-3: Third section of inner shell

[0057] D: Hollow pattern E: Gap between inner and outer shell G1: First thread

[0058] G2: Second thread H: Reserved height between the first thread and the second thread DETAILED DESCRIPTION

[0059] The embodiments of the present application are described in detail below. The embodiments described below are exemplary and intended to be used to explain the present application, but should not be understood as limiting the present application.

[0060] This application is based on the following findings and knowledge of the applicant:

[0061] When silicon carbide seed crystals are grown at 2000℃~2300℃, 4H single crystals with consistent crystal form can be prepared, and the crystal growth rate is fast, and the required growth time is relatively short. However, at 2000℃~2300℃, silicon carbide seed crystals will also grow 15R single crystals and 6H single crystals, resulting in the grown crystals being polymorphic single crystals, and the higher the temperature, the easier it is to grow polymorphic single crystals. For this reason, the related art reduces the growth temperature to 1800℃~2000℃. Although this can avoid the appearance of polymorphic single crystals to a certain extent, the lower the temperature, the lower the thermal field effect, resulting in a slower transmission speed of the crystal growth raw material after it sublimates into raw material gas to the seed crystal, thereby requiring a longer growth time, generally 12 days to 15 days, which is not conducive to mass production. On the other hand, during the growth process, the raw material gas will erode the graphite thermal field during transmission, causing some carbon particles in the graphite thermal field to fall off. The carbon particles will be transmitted into the crystal along with the raw material gas, causing inclusions in the crystal, affecting the crystal quality.

[0062] Based on the above findings, the inventors considered that by generating a bottom-up pressure difference in the channel where the raw material gas is transmitted to the seed crystal when growing crystals at 1800℃~2000℃, the transmission speed of the raw material gas can be increased, thereby shortening the crystal growth time. In addition, by filtering and removing particles in the raw material gas during crystal growth, the crystal quality can be further improved.

[0063] In view of this, in the first aspect of the present application, a filter-flow guide module 6 for a crystal growth device is proposed, referring to Figure 1 ,include:

[0064] The outer shell 1 defines a receiving space therein;

[0065] The inner shell 2 is arranged in the accommodating space, and the interior of the inner shell defines a transmission channel 3. The inner shell includes a first section 2-1, a second section 2-2 and a third section 2-3 from top to bottom. The first section, the second section and the third section are independently rotatably connected to the outer shell.

[0066] The filter-flow guide module is a three-stage design, and all three stages can rotate independently. According to the core law of fluid mechanics: for incompressible fluids, pressure energy + dynamic potential energy + kinetic energy = constant. In this application, as an example, during the crystal growth process, when the raw gas is transmitted from bottom to top in the transmission channel, by adjusting the rotational speeds of the first, second and third stages of the inner shell, the rotational speed of the first stage of the transmission channel is greater than the rotational speed of the second stage and greater than the rotational speed of the third stage, resulting in the pressure energy of the first stage of the transmission channel being less than the pressure energy of the second stage and less than the pressure energy of the third stage, thereby generating a positive pressure difference from bottom to top in the transmission channel. When the raw gas is transmitted in the transmission channel, the positive pressure difference generated in the transmission channel can increase the transmission speed of the raw gas for crystal growth and shorten the time for the raw gas to be transmitted along the same path, thereby greatly improving the crystal growth efficiency.

[0067] In some embodiments, reference Figure 1 The filter-guiding module also includes: an air inlet component 4, which is arranged at the lower end of the transmission channel 3 and is used to allow the raw gas to enter the filter-guiding module, thereby further accelerating the transmission speed of the raw gas and improving the crystal growth efficiency.

[0068] In some embodiments, reference Figure 1 The filter-flow guide module further includes a gas outlet assembly 5 disposed at the upper end of the transmission channel 3 for allowing the raw gas to exit the filter-flow guide module. This facilitates rapid transmission of the raw gas to the seed crystal, thereby improving crystal growth efficiency.

[0069] In some embodiments, the air inlet assembly and the air outlet assembly each independently include a fan, and the fan includes at least one exhaust fan structure, thereby promoting the raw gas to enter the transmission channel or output the transmission channel through the operation of the exhaust fan.

[0070] In some embodiments, the rotation direction of the gas outlet component 5 in the filter-guiding module can be opposite to the rotation direction of the gas inlet component 4. Therefore, after the crystal growth is completed, the rotation direction of the gas outlet component can be set to the opposite direction of the rotation of the gas inlet component, which can immediately prevent the upward transmission of the gas in the transmission channel, thereby achieving a good blocking effect.

[0071] In some embodiments, reference Figure 2 , the radial dimension of the transmission channel gradually decreases from bottom to top. According to the law of conservation of mass in fluid mechanics, when the fluid flows steadily in the channel, the mass of the fluid passing through any cross section per unit time is equal, and the expression is A1V1=A2V2=constant, where A1 and A2 are the channel cross-sectional areas, and V1 and V2 are the fluid flow rates. If the flow channel cross-sectional area A1 decreases, the flow rate V1 will inevitably increase. Conversely, if the cross-sectional area increases, the flow rate decreases. According to the aforementioned core law of fluid mechanics, the Bernoulli equation, the radial dimension of the transmission channel gradually decreases from bottom to top, which will also generate a positive pressure difference from bottom to top, thereby further increasing the crystal growth rate.

[0072] In some embodiments, reference Figure 2 , the radial dimension of the transmission channel R1≥R2≥R1 / 2; wherein, R1 is the radial dimension of the bottom of the transmission channel, and R2 is the radial dimension of the top of the transmission channel. Thus, a positive pressure difference from bottom to top is generated in the transmission channel. If R2 is too small, eddy currents will cause vibration and cavitation noise in the transmission channel, and long-term operation may cause fatigue damage to the filter-guiding device; if R1 is too large, the raw gas transmission speed at the inlet of the transmission channel will be too small, which is insufficient to generate a pressure difference.

[0073] In some embodiments, reference Figure 1 The first, second, and third sections of the inner housing of the filter-flow module can all be spirally ascending tubular structures. As the inner housing rotates, the centrifugal force generated by the feed gas changes direction during transmission, creating more regular spiral streamlines. This reduces eddy current losses caused by the change in direction and helps more efficiently convert energy into pressure differential energy. For example, the spiral inlet design of a turbocharger uses this spiral structure to smoothly accelerate the airflow, reducing turbulent noise and energy loss.

[0074] In some embodiments, reference Figure 1The inner shell has a hollow pattern D on its sidewall, and a gap E is defined between the inner shell 2 and the outer shell 1. This allows carbon particles carried in the feedstock gas to be filtered out through the hollow pattern during crystal growth and collected in the gap between the inner and outer shells. This prevents inclusions in the grown crystals, thereby improving crystal growth quality.

[0075] Specifically, the hollow pattern includes a spiral opening, and thus the hollow pattern is adapted to the structure of the inner shell, which helps to remove carbon particles in the raw gas from the spiral opening with the help of the centrifugal force generated by the rotation of the inner shell, thereby achieving the effect of filtering carbon particles.

[0076] In some embodiments, reference Figure 1 , the radial dimension of the transmission channel is R, and the dimension F of the hollow pattern in the direction perpendicular to the radial dimension of the transmission channel satisfies F=R / 20~R / 5, and can be specifically R / 5, R / 6, R / 7, R / 8, R / 9, R / 10, R / 11, R / 12, R / 13, R / 14, R / 15, R / 16, R / 17, R / 18, R / 19, R / 20, etc. The above range can basically ensure the filtration and removal of particles in the crystal growth raw materials without affecting the transmission of the crystal growth raw materials, and can basically avoid the problems of the hollow pattern being too large in the direction perpendicular to the radial dimension of the transmission channel, which hinders the transmission of the raw material gas, and the drainage effect being poor due to being too small, thereby hindering the filtration and removal of carbon particles.

[0077] Further, refer to Figure 2 When the radial dimension of the transmission channel decreases from bottom to top, R1 is the radial dimension of the bottom of the transmission channel, and the dimension F of the hollow pattern in the direction perpendicular to the radial dimension of the transmission channel satisfies F=R1 / 20~R1 / 5, and specifically can be R1 / 5, R1 / 6, R1 / 7, R1 / 8, R1 / 9, R1 / 10, R1 / 11, R1 / 12, R1 / 13, R1 / 14, R1 / 15, R1 / 16, R1 / 17, R1 / 18, R1 / 19, R1 / 20, etc. The above range can ensure the filtration and removal of particles in the crystal growth raw materials without affecting the transmission of the crystal growth raw materials.

[0078] In some embodiments, the inner sides of the inner shell and the outer shell need to be polished, and the surface finish requirement is ≤3.2, so as to avoid the raw material gas from corroding the inner shell and the outer shell, and also to avoid the surface of the inner shell and the outer shell being too rough to hinder the transmission of gas.

[0079] In a second aspect of the present application, a crystal growth device is proposed, referring to Figure 3, including the aforementioned filtering-guiding module 6, using the crystal growth device to perform crystal growth can effectively improve the crystal growth efficiency and at the same time improve the crystal quality.

[0080] In some embodiments, reference Figure 3 The crystal growth device also includes: a crucible 7 for accommodating crystal growth raw materials, thereby helping to isolate the crystal growth raw materials from the outside world to avoid contamination, and further fix the position and shape of the crystal growth raw materials to ensure smooth crystal growth.

[0081] During the crystal growth process, the raw material gas is gradually transferred to the seed crystal, and the height of the crystal growth raw material in the crucible will gradually decrease, which indirectly increases the transmission path of the raw material gas and also affects the heating degree of the raw material gas to a certain extent, thereby affecting the crystal quality. In this application, the distance between the crystal growth raw material and the seed crystal can be kept unchanged by adjusting the equipment, thereby further improving the crystal growth efficiency and crystal quality.

[0082] In some embodiments, reference Figure 3 The crystal growth apparatus further includes a graphite cover 8, which is movable up and down on the crucible 7. The filter-flow guide module 6 is disposed on the inner wall of the graphite cover 8. The movable graphite cover can solve the problem of the distance between the raw material and the seed crystal gradually increasing as the raw material is consumed during the crystal growth process. By adjusting the up and down movement of the graphite cover, the distance between the upper surface of the raw material and the crystal growth interface can be ensured to remain stable, which can also increase the crystal growth rate to a certain extent and improve the crystal quality.

[0083] In some embodiments, reference Figure 3 The crystal growth device further includes: a rotating shaft 9, which is arranged above the graphite cover 8. Thus, the up and down movement of the graphite cover can be adjusted by rotating the rotating shaft, and the operation process is simple.

[0084] In some embodiments, reference Figure 3 The crystal growth device further includes: a driving component 10, connected to the rotating shaft 9, for driving the graphite cover to rotate through the rotating shaft 9, thereby enabling the graphite cover to move up and down with the help of the driving component. Specifically, the driving component can be a motor, thereby ensuring precise control of the rotation speed by setting program parameters, thereby further ensuring the quality of crystal growth.

[0085] Specifically, the rotation speed P of the rotating shaft is 0.01rpm~1rpm, specifically 0.01rpm, 0.1rpm, 0.2rpm, 0.3rpm, 0.4rpm, 0.5rpm, 0.6rpm, 0.7rpm, 0.8rpm, 0.09rpm, 1rpm, etc., and can be rotated according to the height to which the crystal growth raw material descends during the actual crystal growth process.

[0086] In some embodiments, reference Figure 3 The crystal growth device further comprises a base 11, and the crucible 7 is fixedly connected to the base 11. Thus, the stability of the crystal growth device is improved.

[0087] In some embodiments, a first thread G1 is provided on the upper edge of the crucible 7, and a second thread G2 is provided on the lower edge of the graphite cover 8. The first thread and the second thread match each other. Thus, the graphite cover and the crucible are connected by the thread, which is simple to install and can further improve the flexibility of the crystal growth device.

[0088] Further, refer to Figure 3 , the connection between the first thread G1 and the second thread G2 needs to reserve a certain movable height H before crystal growth. Specifically, the movable height is the height of the non-contact area between the first thread and the second thread, that is, the non-engaged area. The movable height H and the crystal growth time satisfy: H=QPt, where Q is the pitch of the first thread and the second thread, t is the crystal growth time, P is the rotation speed of the rotating shaft, and Q×P is the height of the first thread descending per unit time. Here, the pitch is not limited, and the reserved height can be adjusted according to the actual pitch. As a result, it is helpful to maintain a consistent distance between the crystal growth raw material and the seed crystal during the crystal growth process, thereby further improving the crystal growth rate and crystal growth quality.

[0089] In addition, conventional crystal growth devices in related art, refer to Figure 4 The apparatus comprises a crucible 7 and a graphite cover 8. A seed crystal 8 is disposed inside the graphite cover 8. The crucible 7 contains a crystal growth feedstock 13. The crucible and graphite cover of the crystal growth apparatus are fixedly connected. During crystal growth using the apparatus, as the crystal growth feedstock is consumed, the distance between the crystal growth feedstock and the seed crystal increases, which, to a certain extent, slows the crystal growth rate and also affects the crystal quality.

[0090] In a third aspect of the present application, a method for crystal growth using the aforementioned crystal growth apparatus is provided, comprising: continuously rotating the first, second, and third sections of the transmission channel during the crystal growth process. This generates a positive pressure differential from bottom to top in the transmission channel during the crystal growth process, thereby accelerating the transfer of feedstock gas and improving crystal growth efficiency.

[0091] In some embodiments, the radial dimensions of the first section, the second section, and the third section of the transmission channel are the same, and the first section, the second section, and the third section of the transmission channel rotate at speeds of V3, V4, and V5, respectively, V3>V4>V5. According to the aforementioned fluid mechanics theory, kinetic energy and static pressure are converted into each other. Therefore, the static pressures of the first section, the second section, and the third section of the transmission channel satisfy P3<P4<P5, thereby generating a positive pressure difference from bottom to top.

[0092] In some embodiments, the radial dimension of the transmission channel gradually decreases from bottom to top, and the first section, the second section and the third section rotate at the same speed. According to the aforementioned fluid mechanics theory, the cross-sectional area increases and the flow rate decreases. Therefore, the transmission speed of the raw gas between the first section, the second section and the third section of the transmission channel is different, and a positive pressure difference from bottom to top can also be generated.

[0093] In some embodiments, V1 is the rotational speed of the air inlet component in the crystal growth device, V2 is the rotational speed of the air outlet component in the crystal growth device, the filter-guiding module in the crystal growth device includes an air inlet component and an air outlet component, the rotational speeds of the first section, the second section and the third section of the transmission channel, and the rotational speeds between the air inlet component and the air outlet component satisfy V2>V3>V4>V5>V1, thereby helping to generate a positive pressure difference from bottom to top in the filter-guiding device in the crystal growth device, further improving the transmission speed of the raw gas.

[0094] In some embodiments, V1 = 1rpm ~ 100rpm, preferably, V1 = 10rpm ~ 60rpm, specifically 10rpm, 20rpm, 30rpm, 40rpm, 50rpm, 60rpm, etc. The rotation speed of the air intake component within the above range is helpful to input the raw gas into the transmission channel, and can basically avoid the situation where the rotation speed is too low to increase the speed and the rotation speed is too high to interfere with the transmission of the raw gas.

[0095] In some embodiments, V2 = 10 rpm to 150 rpm, preferably, V2 = 40 rpm to 100 rpm, specifically 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, etc. The speed of the gas outlet assembly within the above range is conducive to the transmission of the raw gas to the seed crystal. Further, the speed of the gas inlet assembly and the speed of the gas outlet assembly satisfy 50 rpm ≥ V2 - V1 ≥ 5 rpm, specifically V2 - V1 can be 5 rpm, 10 rpm, 15 rpm, 20 rpm, 25 rpm, 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, etc. The above range is conducive to forming a positive pressure difference from bottom to top in the filter-guiding device; if V2 - V1 is too small, it will not accelerate the transmission and may also hinder the transmission of the raw gas; if V2 - V1 is too large, it is easy to cause interference and diversion, which will also affect the stable transmission of the raw gas.

[0096] In some embodiments, the height of the graphite cap is continuously lowered during crystal growth to maintain a constant distance between the upper surface of the crystal growth feedstock and the lower surface of the growing crystal. This ensures that the path of the feedstock gas to the seed crystal remains constant throughout the crystal growth process, helping to increase crystal growth speed while also preventing uneven heating of the feedstock gas, thereby improving crystal quality.

[0097] It can be understood that the crystal growth method of the present application is implemented through the crystal growth apparatus described above. The specific operations, performance parameters, etc. involved in each step of the crystal growth method can be consistent with the description of the crystal growth apparatus above, and will not be repeated here.

[0098] The present application is described below with reference to specific examples. It should be noted that these examples are merely illustrative and do not limit the present application in any way. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in the art or in the product instructions shall be followed.

[0099] Example 1

[0100] The crystal growth apparatus in this application (refer to Figure 3 ) for crystal growth:

[0101] Parameter settings during crystal growth:

[0102] The rotation rate of the rotating shaft is 0.017 rpm; the movable height (H) between the first and second threads is 24 mm, and the pitch of the threads is 0.2 mm; the speed of the first section of the transmission channel is 35 rpm, the speed of the second section is 30 rpm, and the speed of the third section is 25 rpm; the speed of the air inlet assembly is set to 20 rpm, and the speed of the air outlet assembly is set to 40 rpm;

[0103] The dimension (F) of the hollow pattern in the direction perpendicular to the radial dimension of the transmission channel is set to 0.5 mm, which is 1 / 10 of the radial dimension of the corresponding transmission channel; the crystal growth time is set to 120 h;

[0104] When the program enters the crystal growth stage, the gas outlet assembly and the gas inlet assembly are started at the same time, the crystal growth raw materials are set in the crucible, the crucible and the graphite cover are screwed together to form a dense crystal growth device, and crystal growth begins to obtain crystal A.

[0105] Example 2

[0106] The same as Example 1, the main differences are: the radial dimension of the transmission channel gradually decreases from the bottom, and R2=2 / 3R1; the rotation speed of the transmission channel is set to 30 rpm, and crystal growth is carried out under the above conditions to obtain crystal B.

[0107] Comparative Example 1

[0108] A conventional crystal growth apparatus (ie, without a filtering-guiding device) was used for crystal growth, the crystal growth time was 120 h, and crystal growth was carried out according to the above conditions to obtain crystal C.

[0109] Performance Testing

[0110] Macroscopic inspection: crystal thickness and inclusions.

[0111] Slice detection: microtubule density, screw dislocation, basal plane dislocation, edge dislocation, etc. of the crystal. The test data of the crystals prepared in Examples 1 to 2 and Comparative Example 1 are shown in Table 1.

[0112] The crystal A obtained in Example 1 was tested using a dislocation defect detector. The dislocation results of the slices were shown in Figure 2. Figure 5 .

[0113] The crystal B obtained in Example 2 was tested using a dislocation defect detector. The dislocation results of the slices were shown in Fig. Figure 6 .

[0114] The crystal C obtained in Example 3 was tested using a dislocation defect detector. The dislocation results of the slices were shown in Fig. Figure 7 .

[0115] Table 1

[0116]

[0117] Conclusion: Using the crystal growth device in this application for crystal growth can effectively improve the crystal growth rate and crystal quality.

[0118] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0119] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0120] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A filter-flow guide module for a crystal growth device, characterized in that: include: An outer shell defines a receiving space therein; An inner shell is arranged in the accommodating space, and a transmission channel is defined inside the inner shell. The inner shell includes a first section, a second section and a third section from top to bottom, and the first section, the second section and the third section are independently rotatably connected to the outer shell.

2. The filter-flow guide module according to claim 1, characterized in that: The radial dimension of the transmission channel gradually decreases from bottom to top.

3. The filter-flow guide module according to claim 2, characterized in that: The radial dimension of the transmission channel is R1≥R2≥R1 / 2; Wherein, R1 is the radial dimension of the lowermost end of the transmission channel, and R2 is the radial dimension of the uppermost end of the transmission channel.

4. The filter-flow guide module according to claim 1, characterized in that: A hollow pattern is provided on the side wall of the inner shell, and a gap is provided between the inner shell and the outer shell.

5. The filter-flow guide module according to claim 4, characterized in that: The hollow pattern satisfies at least one of the following conditions: The hollow pattern includes a spiral opening; The dimension F of the hollow pattern in the direction perpendicular to the radial dimension of the transmission channel and the radial dimension R1 of the transmission channel satisfy F=R1 / 20~R1 / 5; Wherein, R1 is the radial dimension of the lowermost end of the transmission channel.

6. The filter-flow guide module according to claim 1, characterized in that: Also includes at least one of the following: An air intake assembly, disposed below the transmission channel, for allowing the raw gas to enter the filter-guiding module; The gas outlet component is arranged above the transmission channel and is used to output the raw gas from the filtering-guiding module.

7. The filter-flow guide module according to claim 6, characterized in that: The air inlet assembly and the air outlet assembly each independently include a fan.

8. A crystal growth device, characterized in that: The invention comprises the filter-flow guide module according to any one of claims 1 to 7.

9. The crystal growth apparatus according to claim 8, wherein: Also includes: Crucible, used to hold crystal growth raw materials; A graphite cover that can move up and down is arranged on the crucible, and the filtering-guiding module is arranged on the inner wall of the graphite cover.

10. The crystal growth apparatus according to claim 9, wherein: The upper edge of the crucible is provided with a first thread, and the lower edge of the graphite cover is provided with a second thread, and the first thread and the second thread match.

11. The crystal growth apparatus according to claim 10, wherein: A movable height H is reserved between the first thread and the second thread; The movable height refers to the height of a non-contact region between the first thread and the second thread.

12. The crystal growth apparatus according to claim 11, wherein: Also includes: A rotating shaft is arranged above the graphite cover; A driving assembly is connected to the rotating shaft and is used to drive the graphite cover to rotate through the rotating shaft.

13. The crystal growth apparatus according to claim 12, wherein: Also includes: A base is provided, and the crucible is fixedly connected to the base.

14. A method for growing crystals using the crystal growth apparatus according to any one of claims 8 to 13, characterized in that: include: During the crystal growth process, the first section, the second section and the third section of the transport channel are continuously rotated.

15. The crystal growth method according to claim 14, characterized in that: Meet any of the following conditions: The first section, the second section and the third section rotate at speeds of V3, V4 and V5 respectively, and V3>V4>V5; The radial dimension of the transmission channel gradually decreases from bottom to top, and the first section, the second section and the third section rotate at the same speed.

16. The crystal growth method according to claim 15, characterized in that: The filter-guiding module in the crystal growth device includes an air inlet component and an air outlet component and meets at least one of the following conditions: V2>V3>V4>V5>V1; 50rpm≥V2-V1≥5rpm; V1=1rpm~100rpm; V2 = 10 rpm ~ 150 rpm; Wherein, V1 is the rotation speed of the air inlet component in the crystal growth device, and V2 is the rotation speed of the air outlet component in the crystal growth device.

17. The crystal growth method according to claim 14, characterized in that: During the crystal growth process, the height of the graphite cap continues to decrease so that the distance between the upper surface of the crystal growth feedstock and the lower surface of the growing crystal remains constant.

18. The crystal growth method according to claim 17, characterized in that: The graphite cover is continuously rotated along a thread matched with the crucible so that its height is continuously reduced, and the rotation speed P of the graphite cover is 0.01 rpm to 1 rpm.

Images