Crystal growth equipment

Abstract

An embodiment of the present specification provides a crystal growth apparatus, comprising: a crucible including a raw material chamber for placing raw materials and a growth chamber for crystal growth; and the heat preservation device is arranged on at least one side surface outside the crucible.

Description

Crystal growth equipment

[0001] Cross-references

[0002] This application claims priority to Chinese application No. 202210511620.6 filed on May 12, 2022, and priority to Chinese application No. 202210584487.7 filed on May 27, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of crystal growth technology, and in particular to a crystal growth device. Background Art

[0004] When using physical vapor transport (PVT) to grow crystals (e.g., semiconductor crystals), the crucible must be heated and protected by an insulating layer. A seed crystal is placed inside the crucible's upper cover, allowing the crystal to grow on top of it.

[0005] Summary of the Invention

[0006] One or more embodiments of the present specification provide a crystal growth device, comprising: a crucible comprising a raw material cavity for placing raw materials and a growth cavity for crystal growth; and a heat preservation device disposed on at least one side outside the crucible.

[0007] In some embodiments, the crucible includes an upper cover, which includes a cover body and a seed crystal holder, and the seed crystal holder is detachably connected to the cover body.

[0008] In some embodiments, the seed crystal holder includes a connection structure, and the connection structure is disposed in a central area of ​​a side of the seed crystal holder close to the cover.

[0009] In some embodiments, the seed pad has a thickness of 2 mm to 10 mm.

[0010] In some embodiments, two surfaces of the seed holder in contact with the cover include mutually matching concave and convex structures.

[0011] In some embodiments, the seed crystal holder includes a separation groove for separating the seed crystals on the seed crystal holder.

[0012] In some embodiments, the separation groove is a circumferential groove, and the circumferential groove is arranged on the outer circumference of a side away from the cover body.

[0013] In some embodiments, a ratio of a radial depth of the circumferential groove to a radius of the seed pad is in a range of 0.028-0.042.

[0014] In some embodiments, the depth of the circumferential groove along the radial direction is 2 mm-4 mm, and the height of the circumferential groove along the axial direction is 0.5 mm-1.5 mm.

[0015] In some embodiments, the crucible includes a flow guiding device disposed between the raw material chamber and the growth chamber, and the flow guiding device includes a first flow guiding surface inclined toward a bottom surface of the raw material chamber.

[0016] In some embodiments, the guide device includes a guide groove, which is a groove arranged on the outer periphery of the guide device.

[0017] In some embodiments, the guide groove includes a second guide surface that is parallel or substantially parallel to the first guide surface, and a guide wall is formed between the first guide surface and the second guide surface.

[0018] In some embodiments, the flow guiding device further includes a supporting wall, wherein the supporting wall radially connects the flow guiding wall and the outer peripheral wall of the crucible.

[0019] In some embodiments, the guide wall has a thickness of 10 mm to 60 mm.

[0020] In some embodiments, the height of the guide groove ranges from 20 mm to 40 mm.

[0021] In some embodiments, the ratio of the thickness of the guide wall to the height of the guide groove is in the range of 0.2-1.5.

[0022] In some embodiments, the thickness of the support wall ranges from 10 mm to 60 mm.

[0023] In some embodiments, the ratio of the thickness of the guide wall to the thickness of the support wall is in the range of 0.8-1.2.

[0024] In some embodiments, the crystal growth equipment also includes a furnace chamber and a temperature measuring structure, the crucible is arranged in the furnace chamber, the temperature measuring structure includes a temperature measuring cavity and a temperature measuring window, the temperature measuring cavity includes a first cavity section, a main body and a second cavity section, the temperature measuring window is arranged in the first cavity section, and the second cavity section is connected to the furnace chamber.

[0025] In some embodiments, a diameter of the main body portion is smaller than a diameter of the furnace cavity.

[0026] In some embodiments, the diameter of the first lumen segment and / or the second lumen segment is smaller than the diameter of the main body portion.

[0027] In some embodiments, the temperature measurement structure further includes an air inlet and an air outlet, the air inlet is connected to the first cavity section, and the air outlet is connected to the second cavity section.

[0028] In some embodiments, a diameter of the air outlet is smaller than a diameter of the air inlet.

[0029] In some embodiments, the temperature measurement structure further includes a cooler, and the cooler is disposed in the second cavity section.

[0030] In some embodiments, the temperature measurement structure further includes a deposition chamber, which is communicated with the furnace chamber.

[0031] In some embodiments, the temperature in the deposition chamber is lower than the temperature in the furnace chamber.

[0032] In some embodiments, the temperature measurement structure further includes a deposition chamber, and the deposition chamber is connected to the second chamber section.

[0033] In some embodiments, the temperature in the deposition chamber is lower than the temperature in the furnace chamber and the temperature in the temperature measurement chamber, and the pressure in the deposition chamber is lower than the pressure in the temperature measurement chamber.

[0034] In some embodiments, the insulation device includes a first insulation component, which includes: an inner layer, the thickness of which meets preset conditions; an outer layer, the material of which is different from that of the inner layer; and a middle layer, which is located between the inner layer and the outer layer.

[0035] In some embodiments, the first heat preservation component is at least disposed on a peripheral side of the crucible.

[0036] In some embodiments, the thickness of the inner layer ranges from 4 mm to 57 mm.

[0037] In some embodiments, the thickness of the middle layer ranges from 28 mm to 143 mm.

[0038] In some embodiments, the thickness of the middle layer is greater than the thickness of the inner layer and the thickness of the outer layer.

[0039] In some embodiments, the thickness ratio of the inner layer to the middle layer is between 1:2 and 1:10.

[0040] In some embodiments, the thickness ratio of the middle layer to the outer layer is between 2:0.5 and 10:3.

[0041] In some embodiments, the thickness ratio of the inner layer to the outer layer is between 1:0.5 and 1:3.

[0042] In some embodiments, the inner layer includes at least two insulation sections, and the at least two insulation sections are stacked one above the other.

[0043] In some embodiments, the inner layer has different thicknesses along the axial direction.

[0044] In some embodiments, the material of the inner layer includes graphite felt.

[0045] In some embodiments, the material of the outer layer includes at least one of zirconium oxide, aluminum oxide, carbon material or carbon fiber material.

[0046] In some embodiments, graphite paper is filled between the middle layer and the outer layer.

[0047] In some embodiments, the heat preservation device further includes a second heat preservation component, and the second heat preservation component is disposed on the top of the crystal growth equipment.

[0048] In some embodiments, the second thermal insulation layer includes a stacked structure, and the stacked structure is made of the same material.

[0049] In some embodiments, the heat preservation device further includes a third heat preservation component, and the third heat preservation component includes an annular structure or a circular structure.

[0050] In some embodiments, the inner diameter of the annular structure ranges from 10 mm to 90 mm.

[0051] In some embodiments, a ratio of an outer diameter of the annular structure to a radius of the crucible is 0.6-1.2.

[0052] In some embodiments, the ratio of the inner diameter to the outer diameter of the annular structure is in the range of 0.1-0.8.

[0053] In some embodiments, a ratio of an inner diameter of the annular structure to a radius of the crucible is in a range of 0.1-0.9. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present application will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0055] FIG1 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0056] FIG2 is a schematic structural diagram of an upper cover according to some embodiments of this specification;

[0057] FIG3 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0058] FIG4 is a partial enlarged schematic diagram of the seed crystal holder shown in FIG2 ;

[0059] FIG5 is a schematic structural diagram of an upper cover according to some embodiments of this specification;

[0060] FIG6 is a schematic structural diagram of a seed crystal holder according to some embodiments of this specification;

[0061] FIG7 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0062] FIG8 is a schematic structural diagram of a flow guiding device according to some embodiments of this specification;

[0063] FIG9A is a cross-sectional schematic diagram of a crystal growth apparatus according to some embodiments of the present specification;

[0064] FIG9B is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0065] FIG10 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0066] FIG11 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0067] FIG12 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0068] FIG13 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0069] FIG14 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0070] FIG15 is a schematic structural diagram of a temperature measurement structure according to some embodiments of this specification;

[0071] FIG16 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0072] FIG17A is a schematic structural diagram of the inner layer of the first thermal insulation component according to some embodiments of this specification;

[0073] FIG17B is a schematic structural diagram of a heat preservation section according to some embodiments of this specification;

[0074] FIG17C is a schematic structural diagram of the inner layer of the first thermal insulation assembly according to some embodiments of this specification;

[0075] FIG17D is a schematic structural diagram of the inner layer of the first thermal insulation assembly according to some embodiments of this specification;

[0076] FIG18 is a schematic structural diagram of a first heat preservation assembly according to some embodiments of this specification;

[0077] FIG19 is a schematic structural diagram of a first heat preservation assembly according to some embodiments of this specification;

[0078] FIG20 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of this specification;

[0079] FIG. 21 is a schematic structural diagram of a crystal growth apparatus according to some embodiments of the present specification. DETAILED DESCRIPTION

[0080] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0081] FIG1 is a schematic diagram of the structure of a crystal growth apparatus according to some embodiments of the present specification. The crystal growth apparatus is described in detail below in conjunction with FIG1. ​​In some embodiments, the crystal growth apparatus 10 can prepare crystals (e.g., semiconductor crystals, such as silicon carbide crystals, aluminum nitride crystals, zinc oxide crystals, zinc antimonide crystals, etc.) based on a physical vapor transport method. In some embodiments, as shown in FIG1, the crystal growth apparatus 10 may include a crucible 100, a heating assembly (not shown in FIG1), and a heat preservation device 200. The heat preservation device 200 is disposed on at least one side outside the crucible 100.

[0082] Crucible 100 can be used as a container for storing materials needed for crystal growth and is used to grow crystals in a high-temperature environment. In some embodiments, crucible 100 can include a raw material chamber 102 for placing raw materials and a growth chamber 101 for crystal growth. In some embodiments, raw material chamber 102 is located below growth chamber 101, and raw material chamber 102 and growth chamber 101 are in gas communication.

[0083] In some embodiments, the raw material chamber 102 can be used to store raw materials such as silicon carbide, aluminum nitride, zinc oxide or zinc antimonide, and the raw materials can be sublimated into gas phase components under high temperature (for example, taking the preparation of silicon carbide crystals as an example, the gas phase components may include Si2C, SiC2, Si).

[0084] In some embodiments, a seed crystal 303 may be disposed within growth chamber 101. Gas-phase components crystallize upon contact with the seed crystal within growth chamber 101 to form a crystal. In some embodiments, seed crystal 303 may be fixedly bonded to the inner side surface (e.g., the center of the inner side surface) of the top (e.g., the upper cover) of crucible 100.

[0085] The heating assembly can be arranged outside the crucible 100 (for example, arranged around) the crucible 100 for heating the crucible 100. During the crystal growth process, the heating parameters of the heating assembly can be controlled so that an axial temperature gradient is formed between the raw material and the seed crystal 303. The raw material can be decomposed and sublimated into gaseous components when heated (for example, taking the preparation of silicon carbide crystals as an example, the gaseous components can include Si2C, SiC2, Si). Under the driving action of the axial temperature gradient, the gaseous components are transferred from the surface of the raw material to the surface of the seed crystal 303. Since the temperature at the seed crystal 303 is relatively low, the gaseous components crystallize on the surface of the seed crystal 303 to form a crystal. In some embodiments, the heating assembly can include an induction heating assembly, a resistance heating assembly, etc.

[0086] The heat preservation device 200 can reduce heat exchange between the crucible 100 and the outside of the crucible 100, thereby maintaining a stable temperature within the crucible 100. In some embodiments, the heat preservation device 200 can have a single-layer structure or a multi-layer structure. In some embodiments, the heat preservation device 200 can fully cover the sidewalls and / or bottom of the crucible 100. For more information about the heat preservation device 200, please refer to the description elsewhere in this specification.

[0087] In some embodiments, taking the preparation of silicon carbide crystals as an example, silicon carbide raw materials are loaded into the raw material chamber 102. A seed crystal 303 is loaded into the growth chamber 101, with the seed crystal 303 facing downward. The crucible 100 is heated by a heating assembly, causing the silicon carbide in the raw material chamber 102 to sublime and produce gaseous components. The gaseous components rise into the growth chamber 101 and come into contact with the seed crystal 303, crystallizing on the surface of the seed crystal 303 to grow a crystal. The heat preservation device 200 is disposed outside the crucible 100 to insulate the crucible 100 and maintain the temperature within the crucible 100 within the temperature range required for crystal growth.

[0088] Hereinafter, each component of the crystal growth apparatus 10 and its detailed structure will be described.

[0089] Figure 2 is a schematic diagram of the structure of an upper cover according to some embodiments of this specification. The upper cover is described in detail below in conjunction with Figure 2. As shown in Figures 1 and 2, crucible 100 includes an upper cover 300. In some embodiments, the top of crucible 100 is open, and upper cover 300 is disposed at the opening of crucible 100. Upper cover 300 includes a cover body 301 and a seed crystal holder 302. In some embodiments, cover body 301 and seed crystal holder 302 are detachably connected.

[0090] The upper cover 300 can be connected to the opening of the crucible 100 to close the opening, so that the gas phase components are mainly concentrated in the growth chamber. In some embodiments, the upper cover 300 is adapted to the shape of the opening. In some embodiments, the upper cover 300 can be a disc-shaped structure.

[0091] The cover 301 may be a structure in the upper cover 300 mainly used to close the opening. The cover 301 may also serve as a mounting base for mounting the seed crystal holder 302 . The upper cover 300 is connected to the opening of the crucible 100 via the cover 301 .

[0092] The seed crystal holder 302 can be used to support and secure the seed crystal 303. In some embodiments, the seed crystal 303 can be bonded to the lower surface of the seed crystal holder 302. The seed crystal holder 302 is mounted on the lower surface of the upper cover 300. After the upper cover 300 is installed in place, the seed crystal 303 is located in the growth chamber 101.

[0093] In some embodiments, the seed crystal holder 302 is detachably connected to the cover 301. During crystal growth, the seed crystal holder 302 is mounted on the cover 301. After crystal growth is complete, the seed crystal holder 302 can be removed from the cover 301. To remove the crystal, the seed crystal holder 302 can be destroyed or specially treated, while the cover 301 remains in use, thus reducing production costs.

[0094] Figure 3 is a schematic diagram of a crystal growth apparatus according to some embodiments of this specification. The lid is further described below in conjunction with Figure 3. As shown in Figures 2 and 3, in some embodiments, a first stepped surface 304 is provided on the lid 301, and a second stepped surface is provided at the opening of the crucible 100. The first stepped surface 304 and the second stepped surface can be assembled in a coordinated manner. In some embodiments, the first stepped surface 304 is provided on the circumference of the lid 301.

[0095] In some embodiments, there may be a gap between the first step surface 304 and the second step surface, so as to achieve ventilation inside and outside the crucible 100 and prevent the internal pressure of the crucible 100 from being too high.

[0096] In some embodiments, a tiny protrusion structure may be provided on the first stepped surface 304 . When the first stepped surface 304 and the second stepped surface are assembled together, the protrusion structure can be used to adjust the size of the gap formed between the first stepped surface 304 and the second stepped surface.

[0097] 2 , the seed crystal holder 302 includes a connection structure 305 . The connection structure 305 and the seed crystal 303 are disposed on opposite sides of the seed crystal holder 302 .

[0098] In some embodiments, the seed crystal holder 302 can be detachably connected to the cover body 301 via a connecting structure 305. In some embodiments, the connecting structure 305 may include a clamping structure or a threaded connecting structure. In some embodiments, the connecting structure 305 may include a screw having an external thread, and the cover body 301 is provided with an internal threaded hole connected to the external thread. In some embodiments, the connecting structure 305 may include a threaded hole having an internal thread, and the cover body 301 is provided with a screw connected to the threaded hole. In some embodiments, the connecting structure 305 may be a slider, and the cover body 301 is provided with a groove connected to the slider. In some embodiments, the slider may be a T-shaped slider, and the groove may be a T-shaped groove.

[0099] In some embodiments, the connection structure 305 is disposed in the central region of the seed crystal holder 302 on a side adjacent to the cover 301. In some embodiments, the geometric center of the seed crystal holder 302 coincides with the center of gravity, and the central region may be the region where the geometric center of the seed crystal holder 302 is located. For example, the central region may be a circular region with the geometric center of the seed crystal holder 302 as the center and a radius within a predetermined range.

[0100] By providing a detachable seed crystal holder 302, the seed crystal holder 302 can be separated from the cover 301 after the crystal growth is completed. The crystal removal operation only needs to be completed on the seed crystal holder 302 without destroying the cover 301, so that the cover 301 can be reused.

[0101] Fig. 4 is a partial enlarged schematic diagram of the seed crystal holder shown in Fig. 2. The seed crystal holder will be described in detail below with reference to Fig. 4.

[0102] In some embodiments, after crystal growth is complete, the seed crystal holder 302 can be polished during the crystal retrieval process. Once the material of the seed crystal holder 302 is consumed, the crystal can be retrieved. This method of retrieval can effectively reduce the mechanical stress caused by the retrieval process and prevent damage to the crystal. In some embodiments, the thickness of the seed crystal holder 302 can affect the efficiency and reliability of the crystal retrieval operation. The thinner the seed crystal holder 302, the higher the efficiency of the crystal retrieval. However, the thickness of the seed crystal holder 302 cannot be too thin, so as not to affect the structural strength of the seed crystal holder 302.

[0103] In some embodiments, the thickness a of the seed crystal holder may be 2 mm to 10 mm. In some embodiments, the thickness a of the seed crystal holder may be 3 mm to 9 mm. In some embodiments, the thickness a of the seed crystal holder may be 4 mm to 8 mm.

[0104] Figure 5 is a schematic diagram of the structure of the upper cover according to some embodiments of this specification. The upper cover is described in detail below in conjunction with Figure 5. As shown in Figure 5, the two surfaces of the seed crystal holder 302 that contact the cover 301 include mutually cooperating concave-convex structures. When the seed crystal holder 302 is connected to the cover 301, the cooperating concave-convex structures can be used to increase the contact area and connection strength between the seed crystal holder 302 and the cover 301, while also facilitating heat transfer from the seed crystal holder 302 to the cover 301.

[0105] In some embodiments, the concave-convex structure may include a protruding structure 306 disposed on the seed crystal holder 302 and a concave structure 307 disposed on the cover 301 . The protruding structure 306 and the concave structure 307 may be cooperatively installed.

[0106] In other embodiments, the protrusion structure 306 may be disposed on the cover 301 , and the groove structure 307 may be disposed on the seed holder 302 .

[0107] In some embodiments, the protrusion structure 306 and the groove structure 307 can be fitted on three sides. In some embodiments, a plurality of protrusion structures 306 can be provided, and the protrusion structures 306 are arranged parallel to each other, and the groove structure 307 is arranged one-to-one with the protrusion structure 306. In some embodiments, the cross-section of the protrusion structure 306 (whose cross-section is parallel to the axis direction of the crucible 100) can be one of a rectangle, a triangle, a semicircle, and a semi-ellipse, and the cross-section of the groove structure 307 is arranged corresponding to the protrusion structure 306. In some embodiments, the specific structural shape of the connection structure 305 can be set according to the connection method of the seed crystal holder 302 and the cover body 301. In some embodiments, the seed crystal holder 302 and the cover body 301 can be detachably connected by snapping, and the connection structure 305 can be a slider, and the cover body 301 is provided with a groove connected to the slider, and the cover body 301 and the seed crystal holder 302 can slide relative to each other through the cooperation of the slider and the groove. In some embodiments, the seed crystal holder 302 and the cover body 301 can be detachably connected by snapping or threading. The protrusion structure 306 can be a circular protrusion, and multiple protrusions are coaxially arranged. The groove structure 307 can be a circular groove, and the groove structure 307 is arranged in a one-to-one correspondence with the protrusion structure 306.

[0108] In some embodiments, the seed crystal holder 302 may include a separation groove 308. The separation groove 308 may be a structure that facilitates crystal retrieval. The separation groove 308 facilitates separation of the seed crystal 303 from the seed crystal holder 302. In some embodiments, the separation groove 308 may be configured in different structural forms depending on the crystal retrieval method.

[0109] In some embodiments, the separation groove 308 may include a breakable structure that facilitates the destruction of the seed crystal holder 302. By pre-setting the breakable structure on the seed crystal holder 302, the seed crystal holder 302 can be destroyed during crystal extraction, reducing the amount of seed crystal holder material adhering to the seed crystal 303 and facilitating crystal extraction through methods such as grinding. In some embodiments, the separation groove 308 is provided on the circumferential side of the seed crystal holder 302. The separation groove 308 is a groove structure or crack structure that is concave inward from the circumferential side of the seed crystal holder 302. By applying a force near the separation groove 308, the seed crystal holder 302 is easily cracked from the separation groove 308, making the seed crystal holder 302 more easily destroyed, thereby facilitating the removal of the crystal from the seed crystal holder 302.

[0110] In some embodiments, a plurality of separation grooves 308 (e.g., fragile structures) may be provided along the circumference of the seed holder 302. The plurality of separation grooves 308 may be distributed equidistantly or unequally. In some embodiments, the separation grooves 308 may also be provided around the circumference of the seed holder 302 to form an annular fragile structure (or fragile annular band).

[0111] In some embodiments, the cross-section of the separation slot 308 may be rectangular, triangular, or semicircular.

[0112] In some embodiments, the separation tank 308 may include an auxiliary separation structure to facilitate separation of the seed crystal 303 from the seed crystal holder 302. In some embodiments, the auxiliary separation structure may be provided near the connection surface between the seed crystal holder 302 and the seed crystal 303. Since the seed crystal 303 may be connected to the seed crystal holder 302 by bonding, during crystal retrieval, the auxiliary separation structure may allow bonding and separation liquid to penetrate into the bonding surface between the seed crystal holder 302 and the seed crystal 303, thereby facilitating separation of the seed crystal holder 302 from the seed crystal 303.

[0113] Figure 6 is a schematic diagram of the structure of a seed crystal holder according to some embodiments of this specification. The separation groove is described in detail below in conjunction with Figure 6. As shown in Figure 6, the separation groove 308 is a circumferential groove (i.e., an auxiliary separation structure) disposed on the outer periphery of the seed crystal holder 302 away from the cover 301.

[0114] In some embodiments, a circumferential groove is provided at the edge of the bottom surface of the seed crystal holder 302 (i.e., the side connected to the seed crystal). In some embodiments, the circumferential groove may be in the shape of a concave platform that is recessed toward the cover 301. By providing the circumferential groove, the contact area between the seed crystal holder 302 and the seed crystal 303 can be reduced. After the seed crystal 303 is bonded to the seed crystal holder 302, a space is reserved for accommodating the separation liquid, allowing the bonding separation liquid to directly infiltrate the connection surface between the seed crystal holder 302 and the seed crystal 303, thereby facilitating the destruction of the bonded connection between the seed crystal holder 302 and the seed crystal 303 and making it easier to separate the seed crystal.

[0115] In some embodiments, the depth M of the circumferential groove can affect the wetting effect of the adhesive separation liquid on the connection surface between the seed crystal holder 302 and the seed crystal 303. If the depth M is too small, the adhesive separation liquid will not be able to remain in the circumferential groove for a long time and will easily flow out of the circumferential groove, thereby weakening the wetting effect of the adhesive separation liquid on the connection surface between the seed crystal holder 302 and the seed crystal 303. If the depth M is too large, the contact area between the seed crystal holder 302 and the seed crystal 303 will be excessively reduced, and the connection strength between the seed crystal holder 302 and the seed crystal 303 will be reduced, reducing the connection stability between the seed crystal 303 and the seed crystal holder 302. If the contact area is too small, the heat transfer between the seed crystal holder 302 and the seed crystal 303 will also be affected, and the heat transfer efficiency from the edge of the seed crystal 303 to the seed crystal holder 302 will be reduced, resulting in uneven temperature distribution of the seed crystal 303, which may affect the growth of the seed crystal. In order to ensure the wetting effect of the circumferential groove, the depth M should be set within a reasonable range. In some embodiments, the ratio of the radial depth M of the circumferential groove to the radius of the seed pad is in the range of 0.02-0.05. In some embodiments, the ratio of the radial depth M of the circumferential groove to the radius of the seed pad is in the range of 0.028-0.042. In some embodiments, the ratio of the radial depth M of the circumferential groove to the radius of the seed pad is in the range of 0.03-0.04.

[0116] To further ensure the wetting effect of the circumferential groove, the axial height L of the circumferential groove should also be set within a reasonable range. In some embodiments, as shown in Figure 6, the radial depth M of the circumferential groove is 2mm-4mm, and the axial height L of the circumferential groove is 0.5mm-1.5mm. In some embodiments, the radial depth M of the circumferential groove is 2.5mm-3.5mm, and the axial height L of the circumferential groove is 0.8mm-1.2mm.

[0117] FIG. 7 is a block diagram of an exemplary crystal growth apparatus according to some embodiments of the present specification.

[0118] In some embodiments, referring to FIG. 1 and FIG. 7 , the crucible includes a flow guide device 103 disposed between the raw material chamber and the growth chamber.

[0119] The flow guide device 103 can be a device that controls the direction of gas flowing within and / or outside the crucible. In some embodiments, the flow guide device 103 can be disposed between the feedstock chamber and the growth chamber. In some embodiments, the flow guide device 103 can be disposed within the feedstock chamber. In some embodiments, the flow guide device 103 includes a flow channel 104 connecting the feedstock chamber 102 and the growth chamber 101. In some embodiments, the inlet of the flow guide device 103 faces the feedstock chamber, and the end of the flow guide device 103 faces the growth chamber 101. The size of the end of the end (e.g., diameter) is smaller than the size of the inlet. That is, the size of the end of the flow guide channel 104 near the feedstock chamber 102 (i.e., the inlet) is larger than the size of the end near the growth chamber 101 (i.e., the end). In some embodiments, the size of the end of the flow guide channel 104 near the growth chamber 101 (e.g., diameter) is smaller than the size of the feedstock chamber 102. In some embodiments, the shape of the flow guide device 103 can be a hollow frustum. In some embodiments, the shape of the flow guide device 103 can also be various other shapes, including but not limited to a hollow arcuate cone.

[0120] FIG8 is a partial structural block diagram of a flow guiding device of an exemplary crystal growth apparatus according to some embodiments of the present specification.

[0121] In some embodiments, the flow guide device 103 includes a first flow guide surface 1031 that is inclined toward the bottom surface of the feed chamber 102. The first flow guide surface 1031 is located on the outer wall of the feed chamber and below the growth chamber 101. For example, as shown in FIG8 , the bottom of the first flow guide surface 1031 is connected to the inner wall of the feed chamber 102, and the top of the first flow guide surface 1031 extends obliquely toward the growth chamber 101.

[0122] Since the edge area of ​​the seed crystal is closer to the heating component and its temperature is usually slightly higher than that of the central area, by providing a guide device 103 with a first guide surface 1031, the gas phase components flowing from the raw material chamber 102 to the growth chamber 101 can be converged to the center, thereby increasing the temperature of the central area of ​​the growth chamber 101 and the concentration of the gas phase components, reducing the difference between the central temperature and the edge temperature of the seed crystal, and improving the quality of crystal growth.

[0123] In some embodiments, by setting the inclination angle α of the first guide surface 1031 (i.e., the angle between the first guide surface 1031 and the horizontal direction), the flow direction of the high-temperature airflow flowing from the raw material chamber to the growth chamber can be changed, and the temperature distribution of the crystal growth area (e.g., the seed crystal) in the growth chamber and the distribution of the gas phase components in the growth chamber can be adjusted. A smaller inclination angle α is conducive to the high-temperature airflow converging to the center of the crystal growth area, reducing the temperature gradient between the center and the edge, and facilitating uniform growth of the crystal. However, the inclination angle α should not be set too small. A too small inclination angle α may cause the gas phase components to converge excessively to the center, which is not conducive to uniform growth of the crystal. Therefore, in some embodiments, the inclination angle α of the first guide surface can be in the range of 20°-80°. In some embodiments, the inclination angle α of the first guide surface can be in the range of 30°-70°. In some embodiments, the inclination angle α of the first guide surface can be in the range of 40°-60°.

[0124] In some embodiments, the radius of the closing of the flow guide device 103 can also be set to achieve the above-mentioned effect of reducing the temperature gradient between the center and the edge. In some embodiments, the radius of the closing of the flow guide device 103 can be 50 mm to 110 mm. In some embodiments, the radius of the closing of the flow guide device 103 can be 55 mm to 100 mm. In some embodiments, the radius of the closing of the flow guide device 103 can be 60 mm to 90 mm.

[0125] In some embodiments, the flow guiding device 103 includes a flow guiding groove 1032, which is a groove disposed on the outer periphery of the flow guiding device 103. Because the dimension (e.g., diameter) of the end of the flow guiding channel 104 near the growth chamber is smaller than that of the feedstock chamber, the radial thickness of the flow guiding device 103 near the growth chamber is greater. This greater thickness may, to a certain extent, affect the thermal conductivity of the flow guiding device 103. Therefore, by providing the flow guiding groove, the thickness of the flow guiding device 103 can be reduced, making the thickness of the flow guiding device 103 more uniform, thereby improving the thermal conductivity of the flow guiding device 103.

[0126] The flow guide groove 1032 is disposed on the periphery of the flow guide device 103, on the outer wall of the crucible, and below the growth chamber 101. For example, as shown in FIG8 , a circle of concave flow guide grooves 1032 is disposed on the outer wall of the crucible above the feedstock chamber 102. In some embodiments, the flow guide groove 1032 may be in the shape of a conical annular groove. In some embodiments, the flow guide groove 1032 may also have various other shapes, including but not limited to an arcuate annular groove.

[0127] In some embodiments, the guide groove 1032 includes a second guide surface 1033 that is parallel or substantially parallel to the first guide surface 1031. "Substantially parallel" as used in this specification means that the minimum angle between two mutually referenced surfaces or lines does not exceed 10°.

[0128] In some embodiments, second guide surface 1033 faces the outside of crucible 100 and is located below growth chamber 101. In some embodiments, as shown in FIG8 , the bottom of second guide surface 1033 is located on the outer wall of crucible 100, and the top of second guide surface 1033 extends toward growth chamber 101.

[0129] In some embodiments, a guide wall 1034 is formed between the first guide surface 1031 and the second guide surface 1033 .

[0130] The guide wall 1034 may be the crucible wall between the first guide surface 1031 and the second guide surface 1033 outside the raw material chamber 102. For example, as shown in FIG8 , the inner side of the guide wall 1034 is the first guide surface 1031, and the outer side of the guide wall 1034 is the second guide surface 1033. The distance between the first guide surface 1031 and the second guide surface 1033 may be the thickness of the guide wall 1034. It should be noted that when the first guide surface 1031 and the second guide surface 1033 are not parallel, the thickness of the guide wall may be the average distance between the first guide surface 1031 and the second guide surface 1033, which can be calculated by averaging the maximum and minimum distances.

[0131] By adjusting the thickness of the guide wall 1034, the thermal conductivity of the guide device 103 can be changed, thereby affecting the temperature distribution within the crucible 100. In some embodiments, the thickness of the guide wall 1034 can be set within a certain thickness range based on the temperature distribution within the crucible 100. In some embodiments, the thickness of the guide wall 1034 is 10 mm to 60 mm. In some embodiments, the thickness of the guide wall 1034 is 10 mm to 40 mm. In some embodiments, the thickness of the guide wall 1034 is 10 mm to 30 mm.

[0132] In some embodiments, referring to FIG8 , flow guide device 103 further includes a support wall 1035 that radially connects flow guide wall 1034 to the outer peripheral wall of growth chamber 101. In some embodiments, support wall 1035 can be arranged horizontally. In some embodiments, support wall 1035 can also be arranged at an angle to the horizontal. In some embodiments, the angle between support wall 1035 and the horizontal is no greater than 30°.

[0133] By adjusting the thickness of support wall 1035, the heat conduction capacity of flow guide device 103 to growth chamber 101 can be changed, thereby affecting the temperature distribution within growth chamber 101. In some embodiments, the thickness of support wall 1035 can be set within a certain thickness range based on the temperature distribution within growth chamber 101. The thickness of support wall 1035 can be represented by the distance between the inner side surface (the side facing growth chamber 101) and the outer side surface (the side facing flow guide groove 1032) of support wall 1035.

[0134] In some embodiments, the thickness of the support wall 1035 ranges from 10 mm to 60 mm. In some embodiments, the thickness of the support wall 1035 ranges from 15 mm to 50 mm. In some embodiments, the thickness of the support wall 1035 ranges from 20 mm to 40 mm.

[0135] In some embodiments, when the thickness of the support wall 1035 is constant, the height h of the guide groove 1032 can be adjusted to simultaneously change the thickness and length of the guide wall 1034, thereby changing the thermal conductivity of the guide device 103 and, in turn, affecting the temperature distribution within the crucible 100. In some embodiments, the height h of the guide groove 1032 ranges from 20 mm to 40 mm. In some embodiments, the height h of the guide groove 1032 ranges from 22 mm to 38 mm. In some embodiments, the height h of the guide groove 1032 ranges from 25 mm to 35 mm.

[0136] In some embodiments, the ratio of the thickness of the guide wall 1034 to the height h of the guide groove 1032 can represent the degree of inclination (e.g., the inclination angle) of the first guide surface 1031 and the second guide surface 1033. This inclination can further affect the flow of gas-phase components within the guide channel 104, thereby affecting the temperature distribution of the growth chamber 101. In some embodiments, taking into account the temperature distribution within the growth chamber 101, the ratio of the thickness of the guide wall 1034 to the height h of the guide groove 1032 can be set within a certain range. In some embodiments, the ratio of the thickness of the guide wall 1034 to the height h of the guide groove 1032 ranges from 0.2 to 1.5. In some embodiments, the ratio of the thickness of the guide wall 1034 to the height h of the guide groove 1032 ranges from 0.5 to 1. In some embodiments, the ratio of the thickness of the guide wall 1034 to the height h of the guide groove 1032 ranges from 0.2 to 0.8.

[0137] Since the thickness of support wall 1035 primarily affects the ability of guide device 103 to conduct heat to the edge of growth chamber 101, and thus primarily affects the edge temperature of crystal growth, the thickness of guide wall 1034 primarily affects the ability of guide device 103 to conduct heat to the closing area, and thus primarily affects the temperature in the center of growth chamber 101. In some embodiments, to minimize the difference between the center temperature and the edge temperature during crystal growth, the ratio of the thickness of guide wall 1034 to the thickness of support wall 1035 can be set within a certain range.

[0138] In some embodiments, the ratio of the thickness of the guide wall 1034 to the thickness of the support wall 1035 is in a range of 0.8-1.2. In some embodiments, the ratio of the thickness of the guide wall 1034 to the thickness of the support wall 1035 is in a range of 0.6-1.5. In some embodiments, the ratio of the thickness of the guide wall 1034 to the thickness of the support wall 1035 is in a range of 0.9-1.

[0139] Figure 9A is a schematic cross-sectional view of a crystal growth apparatus according to some embodiments of this specification. Figure 9B is a schematic structural view of a crystal growth apparatus according to some embodiments of this specification. The crystal growth apparatus is described in detail below in conjunction with Figures 9A and 9B. As shown in Figures 9A and 9B, the crystal growth apparatus further includes a temperature measurement structure 500. In some embodiments, the temperature measurement structure 500 includes a temperature measurement cavity 501 and a temperature measurement window 502.

[0140] The temperature measurement structure 500 can be used to measure the temperature inside the crystal growth device, thereby determining whether the crystal growth is within a suitable temperature range. When the measured temperature is not within a threshold range, timely measures can be taken.

[0141] In some embodiments, the crystal growth apparatus further includes a furnace chamber 400, and the crucible 100 and the heat preservation device 200 can be disposed within the furnace chamber 400. An opening 401 is provided at the top of the furnace chamber 400, and the temperature measurement structure 500 can be disposed at the opening 401 and communicate with the opening 401. In some embodiments, the furnace chamber 400 is exposed to a high temperature environment (e.g., 1200°C-2000°C or 800°C-1600°C) during operation. Using traditional contact temperature measurement can affect the accuracy of temperature measurement. Therefore, the temperature of the high-temperature furnace can be measured using a non-contact temperature measurement method. In some embodiments, temperature detection can be achieved using infrared temperature measurement.

[0142] The temperature measurement window 502 can serve as a temperature detection window. For example, an infrared thermometer can be used to measure the temperature within the furnace cavity 400 or the crucible 100. The temperature measurement structure 500 is connected to the opening 401, and the infrared thermometer can collect infrared rays emitted from the furnace cavity 400 through the temperature measurement window 502 to achieve temperature measurement. In some embodiments, the temperature measurement window 502 can be made of infrared thermometric glass (e.g., barium fluoride crystal glass).

[0143] FIG10 is a schematic diagram of a temperature measurement structure according to some embodiments of the present disclosure. The temperature measurement structure will be described in detail below with reference to FIG10 .

[0144] In some embodiments, referring to FIG. 10 , the temperature measurement chamber 501 includes a first chamber section 5011, a main body 5012, and a second chamber section 5013. The temperature measurement window 502 is disposed in the first chamber section 5011. The second chamber section 5013 communicates with the furnace chamber 400 to enable temperature monitoring within the furnace chamber 400. In some embodiments, the growth chamber 101 can be in gaseous communication with the furnace chamber 400 through a gap near the lid 300 of the crucible 100, and further in gaseous communication with the second chamber section 5013. In some embodiments, the second chamber section 5013 can also be directly in gaseous communication with the growth chamber 101 through a temperature measurement hole provided in the lid 300, thereby enabling temperature monitoring within the growth chamber.

[0145] The first cavity section 5011 may refer to the top portion of the temperature measurement cavity 501. In some embodiments, the temperature measurement window 502 may be disposed in the first cavity section 5011. In some embodiments, the temperature measurement window 502 may be disposed on the upper end surface of the first cavity section 5011.

[0146] In some embodiments, the temperature measuring window 502 may be parallel or substantially parallel to the upper end surface of the first cavity section 5011. In some embodiments, “substantially parallel” may mean that the angle between the temperature measuring window 502 and the upper end surface of the first cavity section 5011 is within a first preset range.

[0147] In some embodiments, the first preset range may be -10° to 10°. In some embodiments, the first preset range may be -8° to 8°. In some embodiments, the first preset range may be -6° to 6°. In some embodiments, the first preset range may be -5° to 5°. In some embodiments, the first preset range may be -2° to 2°. In some embodiments, the first preset range may be 0° to 1°. In some embodiments, the first preset range may be 1° to 2°.

[0148] In some embodiments, the temperature measuring window 502 may be non-parallel to the upper end surface of the first cavity section 5011, and the angle between the two may be within a second preset range. In some embodiments, the second preset range may be 10° to 60°. In some embodiments, the second preset range may be 15° to 55°. In some embodiments, the second preset range may be 20° to 50°. In some embodiments, the second preset range may be 25° to 45°. In some embodiments, the second preset range may be 30° to 40°. In some embodiments, the second preset range may be 10° to 20°. In some embodiments, the second preset range may be 20° to 30°. In some embodiments, the second preset range may be 50° to 60°.

[0149] The main body portion 5012 may refer to the portion between the first cavity section 5011 and the second cavity section 5013. The second cavity section 5013 may refer to the bottom portion of the temperature measurement cavity 501. In some embodiments, the second cavity section 5013 may be connected to the furnace cavity 400.

[0150] In some embodiments, the main body portion 5012 may be a cavity structure of a body of revolution, and the diameter of the main body portion 5012 is smaller than the diameter of the furnace cavity 400 .

[0151] In some embodiments, the diameter of the main body portion 5012 is much smaller than the diameter of the oven cavity 400. In some embodiments, the ratio of the diameter of the main body portion 5012 to the diameter of the oven cavity 400 may be within a second preset ratio range. In some embodiments, the second preset ratio range may be 1:5 to 1:25. In some embodiments, the second preset ratio range may be 1:8 to 1:22. In some embodiments, the second preset ratio range may be 1:11 to 1:19. In some embodiments, the second preset ratio range may be 1:14 to 1:16. In some embodiments, the second preset ratio range may be 1:5 to 1:20. In some embodiments, the second preset ratio range may be 1:10 to 1:25. In some embodiments, the second preset ratio range may be 1:5 to 1:15. In some embodiments, the second preset ratio range may be 1:15 to 1:25.

[0152] By setting the diameter of the main body 5012 to be smaller than the diameter of the furnace cavity 400, the overall size of the temperature measuring cavity 501 can be made smaller than the size of the furnace cavity 400, which can reduce the impact of the temperature measuring cavity 501 on the crystal growth environment in the furnace cavity 400.

[0153] In some embodiments, the main body portion 5012 may be a tapered section, i.e., the diameter of the main body portion 5012 gradually decreases from the end connected to the first cavity section 5011 to the end connected to the second cavity section 5013. In other words, the shape of the entire temperature measurement cavity 501 is similar to a shape that gradually decreases from the upper end to the lower end.

[0154] In some embodiments, the diameter of the first cavity section 5011 and the diameter of the second cavity section 5013 may both be smaller than the diameter of the main body 5012. That is, the shape of the entire temperature measurement cavity 501 is similar to a shape with small ends and a large middle.

[0155] In some embodiments, referring to FIG11 , the diameter of the second cavity section 5013 may be smaller than the diameter of the main body 5012, while the diameter of the first cavity section 5011 may be greater than or equal to the diameter of the main body 5012. That is, the shape of the entire temperature measurement cavity 501 is similar to a shape with a larger upper end and a smaller lower end.

[0156] By setting the temperature measuring cavity 501 to a shape that is small at both ends and large in the middle, large at one end and small at the other end, or gradually decreasing from the upper end to the lower end, the gas concentration in the temperature measuring cavity 501 can be greater than the gas concentration in the furnace cavity 400 (the gas pressure in the temperature measuring cavity 501 is greater than the gas pressure in the furnace cavity 400). The existence of this pressure difference makes it difficult for the dust generated in the furnace cavity 400 to enter the temperature measuring cavity 501 and then reach the temperature measuring window 502, thereby ensuring the cleanliness of the temperature measuring window 502, which is beneficial to improving the stability and accuracy of the temperature measurement.

[0157] As shown in FIG. 10 , in some embodiments, the temperature measurement structure may further include an air inlet 5014 and an air outlet 5015 .

[0158] The air inlet 5014 can be used to introduce gas into the temperature measurement cavity 501. In some embodiments, the air inlet 5014 can be disposed in the first cavity section 5011. In some embodiments, the air inlet 5014 can be disposed on the sidewall of the first cavity section 5011. In some embodiments, the air inlet 5014 can be disposed on the furnace cavity 400 independently of the temperature measurement cavity 501. In some embodiments, taking crystal growth as an example, the gas introduced into the temperature measurement cavity 501 through the air inlet 5014 can be a gas required for crystal growth, for example, oxygen and / or an inert gas. The inert gas can include nitrogen, helium, neon, xenon, radon, or the like, or any combination thereof.

[0159] In some embodiments, the air inlet 5014 may be disposed near the temperature measuring window 502. In some embodiments, "near" may mean that the distance between the air inlet 5014 and the temperature measuring window 502 is within a preset distance range.

[0160] In some embodiments, the preset distance range may be 1 cm to 10 cm. In some embodiments, the preset distance range may be 3 cm to 8 cm. In some embodiments, the preset distance range may be 5 cm to 6 cm. In some embodiments, the preset distance range may be 1 cm to 3 cm. In some embodiments, the preset distance range may be 3 cm to 5 cm. In some embodiments, the preset distance range may be 5 cm to 8 cm. In some embodiments, the preset distance range may be 8 cm to 10 cm.

[0161] In some embodiments, the distance between the air inlet 5014 and the temperature measuring window 502 can be determined based on the air flow rate of the air inlet 5014 and / or the air flow direction of the air inlet 5014. For example, the greater the air flow rate of the air inlet 5014, the greater the distance between the air inlet 5014 and the temperature measuring window 502 can be; and the smaller the air flow rate, the smaller the distance between the air inlet 5014 and the temperature measuring window 502 can be. For another example, the smaller the angle between the air inlet direction of the air inlet 5014 and the normal to the inner side surface of the temperature measuring window 502, the greater the distance between the air inlet 5014 and the temperature measuring window 502 can be; and the larger the angle between the air inlet direction of the air inlet 5014 and the normal to the inner side surface of the temperature measuring window 502, the smaller the distance between the air inlet 5014 and the temperature measuring window 502 can be. In some embodiments, the air flow rate of the air inlet 5014 can be set according to actual needs, provided that the crystal growth requirements are met and the gas can purge the inner surface of the temperature measuring window 502 .

[0162] In some embodiments, the air inlet 5014 can be directed toward (eg, tilted toward) the temperature measuring window 502. In some embodiments, the angle between the air inlet 5014 and the plane of the temperature measuring window 502 can be within a preset angle range.

[0163] In some embodiments, the preset angle range may be 5° to 60°. In some embodiments, the preset angle range may be 10° to 55°. In some embodiments, the preset angle range may be 15° to 50°. In some embodiments, the preset angle range may be 20° to 45°. In some embodiments, the preset angle range may be 25° to 40°. In some embodiments, the preset angle range may be 30° to 35°. In some embodiments, the preset angle range may be 5° to 20°. In some embodiments, the preset angle range may be 5° to 40°. In some embodiments, the preset angle range may be 25° to 60°.

[0164] In some embodiments, the angle between the air inlet 5014's air inlet direction and the plane of the temperature measuring window 502 can be determined based on the size of the temperature measuring window 502 and / or the distance between the air inlet 5014 and the temperature measuring window 502. For example, the larger the size of the temperature measuring window 502, the larger the angle between the air inlet 5014's air inlet direction and the plane of the temperature measuring window 502 can be; the smaller the size of the temperature measuring window 502, the smaller the angle between the air inlet 5014's air inlet direction and the plane of the temperature measuring window 502 can be. For another example, the smaller the distance between the air inlet 5014 and the temperature measuring window 502, the larger the angle between the air inlet 5014's air inlet direction and the plane of the temperature measuring window 502 can be; and the larger the distance between the air inlet 5014 and the temperature measuring window 502, the smaller the angle between the air inlet 5014's air inlet direction and the plane of the temperature measuring window 502 can be.

[0165] By setting the air inlet 5014 near the temperature measuring window 502 and with the air inlet direction toward the temperature measuring window 502, the gas entering the temperature measuring cavity 501 from the air inlet 5014 can blow away at least a portion of the dust on the inner surface of the temperature measuring window 502, thereby achieving the blowing and cleaning of the temperature measuring window 502, thereby improving the stability and accuracy of the temperature measurement results.

[0166] In some embodiments, the gas outlet 5015 can be used to pass gas into the furnace cavity 400. In some embodiments, the gas outlet 5015 can be disposed in the second cavity section 5013. In some embodiments, the gas outlet 5015 can be disposed on the bottom end surface of the second cavity section 5013. In some embodiments, the gas outlet 5015 can be connected to the gas inlet 5014 of the furnace cavity 400. In some embodiments, the gas outlet 5015 can be directly disposed on the furnace cavity 400 and communicate with the second cavity section 5013.

[0167] By arranging the air inlet 5014 in the first cavity section 5011 and the air outlet 5015 in the second cavity section 5012, the ends of the small-diameter second cavity section 5013 are connected to the larger-diameter main portion 5012 and the furnace chamber 400, respectively, forming a structure similar to a "Venturi tube." Because the airflow flows into the first cavity section 5011 and out of the second cavity section 5012, the pressure at the end of the second cavity section 5013 near the main portion 5012 is greater than the pressure at the end of the second cavity section 5013 near the furnace chamber 400. This pressure difference prevents dust generated within the furnace chamber 400 from entering the temperature measurement cavity 501 and reaching the temperature measurement window 502, thereby ensuring the cleanliness of the temperature measurement window 502 and improving the stability and accuracy of temperature measurement.

[0168] In some embodiments, the pressure difference between the main body 5012 and the furnace cavity 400 can be adjusted by setting the proportional relationship between the diameter of the second cavity section 5012 or the air outlet 5015 and the diameter of other parts of the temperature measuring structure (such as the air inlet 5014, the main body 5012, the furnace cavity 400, etc.), thereby achieving a better effect of ensuring the cleanliness of the temperature measuring window 502.

[0169] In some embodiments, the diameter of the gas outlet 5015 is smaller than the diameter of the main body 5012. In some embodiments, the diameter of the gas outlet 5015 is much smaller than the diameter of the main body 5012. In some embodiments, the ratio of the diameter of the gas outlet 5015 to the diameter of the main body 5012 can be within a first preset ratio range.

[0170] In some embodiments, the first preset ratio range may be 1:5 to 1:20. In some embodiments, the first preset ratio range may be 1:8 to 1:17. In some embodiments, the first preset ratio range may be 1:11 to 1:14. In some embodiments, the first preset ratio range may be 1:5 to 1:15. In some embodiments, the first preset ratio range may be 1:10 to 1:20.

[0171] By setting the diameter of the air outlet 5015 to be smaller than the diameter of the main body 5012 (or the ratio of the two diameters is within a preset range), the gas pressure in the temperature measuring cavity 501 can be greater than the gas pressure in the furnace cavity 400. The existence of this pressure difference makes it difficult for dust generated in the furnace cavity 400 to enter the temperature measuring cavity 501 and then reach the temperature measuring window 502, thereby ensuring the cleanliness of the temperature measuring window 502 and improving the stability and accuracy of the temperature measurement.

[0172] In some embodiments, the diameter of the main body portion 5012 is smaller than the diameter of the oven cavity 400. In some embodiments, the diameter of the main body portion 5012 is much smaller than the diameter of the oven cavity 400. In some embodiments, the ratio of the diameter of the main body portion 5012 to the diameter of the oven cavity 400 may be within a second preset ratio range. In some embodiments, the second preset ratio range may be 1:5 to 1:25. In some embodiments, the second preset ratio range may be 1:8 to 1:22. In some embodiments, the second preset ratio range may be 1:11 to 1:19. In some embodiments, the second preset ratio range may be 1:14 to 1:16. In some embodiments, the second preset ratio range may be 1:5 to 1:20. In some embodiments, the second preset ratio range may be 1:10 to 1:25. In some embodiments, the second preset ratio range may be 1:5 to 1:15. In some embodiments, the second preset ratio range may be 1:15 to 1:25.

[0173] In some embodiments, the diameter of the gas outlet 5015 may be smaller than the diameter of the gas inlet 5014 .

[0174] In some embodiments, the ratio of the diameter of the air outlet 5015 to the diameter of the air inlet 5014 may be within a third preset ratio range. In some embodiments, the third preset ratio range may be 1:1.5 to 1:5. In some embodiments, the third preset ratio range may be 1:2 to 1:4.5. In some embodiments, the third preset ratio range may be 1:2.5 to 1:4. In some embodiments, the third preset ratio range may be 1:3 to 1:3.5. In some embodiments, the third preset ratio range may be 1:1.5 to 1:3.5. In some embodiments, the third preset ratio range may be 1:3 to 1:5.

[0175] By setting the diameter of the air outlet 5015 to be smaller than the diameter of the air inlet 5014, the gas concentration in the temperature measuring cavity 501 can be greater than the gas concentration in the furnace cavity 400 (the gas pressure in the temperature measuring cavity 501 is greater than the gas pressure in the furnace cavity 400). The existence of this pressure difference makes it difficult for the dust generated in the furnace cavity 400 to enter the temperature measuring cavity 501 and then reach the temperature measuring window 502, thereby ensuring the cleanliness of the temperature measuring window 502, which is beneficial to improving the stability and accuracy of the temperature measurement.

[0176] FIG12 is a schematic diagram of a temperature measurement structure according to some embodiments of this specification. The temperature measurement structure is described in detail below in conjunction with FIG9. As shown in FIG12, in some embodiments, the temperature measurement structure may further include a heater 5016.

[0177] The heater 5016 can be used to heat the main body portion 5012. In some embodiments, the heater 5016 can be wrapped around or surround the outer surface of the main body portion 5012 or the peripheral space of the outer surface to uniformly heat the main body portion 5012.

[0178] In some embodiments, the heater 5016 may include a resistive heating component, an induction heating component, etc.

[0179] By heating the main body 5012, the gas temperature in the temperature measuring cavity 501 can be made higher than the gas temperature in the furnace cavity 400, and the gas pressure in the temperature measuring cavity 501 can be made higher than the gas pressure in the furnace cavity 400. The existence of this pressure difference makes it difficult for dust generated in the furnace cavity 400 to enter the temperature measuring cavity 501 and then reach the temperature measuring window 502, thereby ensuring the cleanliness of the temperature measuring window 502, which is beneficial to improving the stability and accuracy of temperature measurement.

[0180] FIG13 is a schematic diagram of a temperature measurement structure according to some embodiments of this specification. The temperature measurement structure is described in detail below in conjunction with FIG10. As shown in FIG13, in some embodiments, the temperature measurement structure may further include a cooler 5017. The cooler 5017 may be used to cool the second cavity section 5013.

[0181] In some embodiments, the cooling method of the cooler 5017 may include water cooling, air cooling, etc. In some embodiments, the cooler 5017 may be disposed (e.g., covered) on the outer surface of the second cavity section 5013 or in the peripheral space of the outer surface to uniformly cool the second cavity section 5013.

[0182] By arranging a cooler 5017 on the outer surface of the second cavity section 5013, the temperature of the second cavity section 5013 can be made lower than the temperature of the main part 5012 to further increase the pressure difference between the main part 5012 and the second cavity section 5013, and the dust generated in the furnace cavity 400 will condense when it encounters cold when it reaches the vicinity of the second cavity section 5013, making it difficult for the dust to enter the temperature measuring cavity 501 and then reach the temperature measuring window 502, thereby effectively preventing the dust from being deposited on the inside of the temperature measuring window 502.

[0183] Figure 14 is a schematic diagram of a temperature measurement structure according to some embodiments of this specification. The temperature measurement structure is described in detail below in conjunction with Figure 11. As shown in Figure 14, in some embodiments, the temperature measurement structure may further include a deposition chamber 600. Deposition chamber 600 may be connected to furnace chamber 400 and is used to deposit dust generated within furnace chamber 400.

[0184] In some embodiments, the deposition chamber 600 may be closed at one end and connected to the furnace chamber 400 at the other end. In some embodiments, the deposition chamber 600 may have two or more communication holes, each of which is connected to the furnace chamber 400 through an independent channel, so that the gas in the furnace chamber 400 can enter the deposition chamber 600 through the channel.

[0185] In some embodiments, there may be two deposition chambers 600, symmetrically disposed on both sides of the furnace chamber 400, so as to maximize the impact on the environment within the furnace chamber 400. In some embodiments, there may be one, three, or more deposition chambers 600, which is not limited in this specification.

[0186] Since the fluidity of the gas in the deposition chamber 600 is relatively poorer than that in the furnace chamber 400, by setting up the deposition chamber 600, the dust generated in the furnace chamber 400 can be deposited in the deposition chamber, thereby reducing the dust entering the temperature measuring chamber 501 and effectively preventing the dust from being deposited on the inside of the temperature measuring window 502.

[0187] In some embodiments, the temperature in the deposition chamber 600 may be lower than the temperature in the furnace chamber 400. In some embodiments, the temperature in the deposition chamber 600 may be controlled by cooling the deposition chamber 600 using a cooler. The configuration of the cooler may be similar to that of the aforementioned cooler 5017 and will not be described in detail herein.

[0188] By controlling the temperature in the deposition chamber 600 to be lower than the temperature in the furnace chamber 400 , the dust in the furnace chamber 400 can be cooled more easily and deposited in the deposition chamber 600 , thereby reducing the deposition of dust inside the temperature measuring window 502 .

[0189] Figure 15 is a schematic diagram of a temperature measurement structure according to some embodiments of this specification. The temperature measurement structure is described in detail below in conjunction with Figure 12 . As shown in Figure 15 , in some embodiments, the temperature measurement structure may further include a deposition chamber 600. The deposition chamber 600 may be connected to the second chamber section 5013 and used to deposit dust generated within the furnace chamber 400 and moved near the second chamber section 5013.

[0190] In some embodiments, the deposition chamber 600 may be closed at one end and connected to the second chamber segment 5013 at the other end. In some embodiments, the deposition chamber 600 may have two or more communication holes, each of which is connected to the second chamber segment 5013 through an independent channel.

[0191] In some embodiments, there may be two deposition chambers 600, symmetrically disposed on both sides of the second chamber section 5013, so as to provide a balanced impact on the environment within the furnace chamber 400. In some embodiments, there may be one, three, or more deposition chambers 600, which is not limited in this specification.

[0192] Since the fluidity of the gas in the deposition chamber 600 is relatively poor compared to the fluidity of the gas in the temperature measuring chamber 501 and the furnace chamber 400, by setting up the deposition chamber 600, the dust generated in the furnace chamber 400 can be easily deposited in the deposition chamber when it moves to the vicinity of the second chamber section 5013, thereby reducing the dust entering the temperature measuring chamber 501 and effectively preventing the dust from being deposited on the inside of the temperature measuring window 502.

[0193] In some embodiments, the temperature in the deposition chamber 600 is lower than the temperature in the furnace chamber 400 and the temperature in the temperature measurement chamber 501 , and the pressure in the deposition chamber 600 is lower than the pressure in the temperature measurement chamber 501 .

[0194] In some embodiments, a cooler may be used to cool the deposition chamber 600 to control the temperature inside the deposition chamber 600. The configuration of the cooler may be similar to that of the aforementioned cooler 5017 and will not be described in detail herein.

[0195] By controlling the temperature in the deposition chamber 600 to be lower than the temperature in the furnace chamber 400 and the temperature in the temperature measuring chamber 501, and controlling the pressure in the deposition chamber 600 to be lower than the pressure in the temperature measuring chamber 501, the dust in the furnace chamber 400 can be more easily cooled and deposited in the deposition chamber 600, thereby reducing the deposition of dust on the inside of the temperature measuring window 502.

[0196] FIG. 16 is a schematic structural diagram of an exemplary crystal growth apparatus according to some embodiments of the present specification.

[0197] In some embodiments, the heat-insulating device 200 may include a first heat-insulating component 201. In some embodiments, the first heat-insulating component 201 is disposed at least on the circumference of the crucible 100. In some embodiments, the first heat-insulating component 201 may be disposed only on the circumference of the crucible 100. In some embodiments, the first heat-insulating component 201 may also be disposed simultaneously on the circumference and bottom of the crucible 100. In some embodiments, the first heat-insulating component 201 may also be disposed simultaneously on the circumference and top of the crucible 100. In some embodiments, the first heat-insulating component 201 may also be disposed simultaneously on the circumference, top, and bottom of the crucible 100. In some embodiments, the first heat-insulating component 201 includes an inner layer 2011, an outer layer 2012, and a middle layer 2013, wherein the middle layer 2013 is located between the inner layer 2011 and the outer layer 2012. By setting up a multi-layer insulation structure combining an inner layer, an outer layer and a middle layer, when the inner layer becomes thinner due to heat volatilization and the outer layer's insulation performance deteriorates due to impurity deposition, the middle layer can still maintain a good insulation effect. The independent structures can make it easier to replace the inner layer and / or outer layer, reducing the cost of insulation device maintenance and improving the efficiency of insulation device maintenance.

[0198] In some embodiments, the thickness of inner layer 2011 must meet predetermined requirements to avoid excessive replacement frequency due to excessive thickness, or excessive cost due to excessive thickness. Furthermore, the thickness of inner layer 2011 can be configured to be independent along the axial direction, maintaining good thermal insulation at different axial locations while facilitating targeted maintenance and replacement based on wear and tear at different locations. This will be described in detail below.

[0199] In some embodiments, the thickness of the inner layer 2011 may be set within a certain thickness range, taking into account the cost and replacement frequency of the inner layer 2011. In some embodiments, the thickness of the inner layer 2011 may be within a range of 4 mm to 57 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 5 mm to 55 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 7 mm to 52 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 10 mm to 50 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 13 mm to 47 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 15 mm to 45 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 17 mm to 43 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 20 mm to 40 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 22 mm to 37 mm. In some embodiments, the thickness of the inner layer 2011 may be within a range of 25 mm to 35 mm. In some embodiments, the thickness of the inner layer 2011 can be in the range of 27 mm to 32 mm. In some embodiments, the thickness of the inner layer 2011 can be in the range of 28 mm to 30 mm.

[0200] By setting the thickness of the inner layer within a certain thickness range, the initial cost of the inner layer can be reduced, the replacement frequency and replacement cost of the inner layer can be reduced, the service life of the inner layer can be increased, and the process stability of the crystal growth process can be maintained.

[0201] In some embodiments, to ensure that the middle layer 2013 maintains a good and stable thermal insulation effect when the inner layer 2011 and outer layer 2012 are depleted, while also considering cost, the thickness of the middle layer 2013 should be set within a certain range. In some embodiments, the thickness of the middle layer 2013 can be within the range of 28 mm to 143 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 30 mm to 140 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 35 mm to 135 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 40 mm to 130 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 45 mm to 135 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 50 mm to 130 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 55 mm to 125 mm. In some embodiments, the thickness of the middle layer 2013 can be within the range of 60 mm to 120 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 65 mm to 115 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 70 mm to 110 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 75 mm to 105 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 80 mm to 100 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 85 mm to 95 mm. In some embodiments, the thickness of the middle layer 2013 may be within a range of 88 mm to 90 mm.

[0202] By setting the thickness of the middle layer within a certain range, the impurities generated by the crucible and the inner layer due to heat volatilization can be evaporated to the outer layer as much as possible, and will not stay in the middle layer, thus not affecting the thermal insulation effect of the middle layer. Accordingly, it can be ensured that when the inner layer becomes thinner due to loss and impurities are deposited in the outer layer, the middle layer can maintain a good and stable thermal insulation effect. There is basically no need to replace the middle layer during the production process, saving production costs.

[0203] In some embodiments, to maximize the deposition of volatiles on the outer layer rather than the middle layer, the combined thickness of the middle layer 2013 and the inner layer 2011 must meet certain requirements. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 50 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 55 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 60 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 65 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 70 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 75 mm. In some embodiments, the combined thickness of the middle layer 2013 and the inner layer 2011 may be greater than 80 mm.

[0204] By setting the total thickness of the middle layer and the inner layer to be greater than a certain value, the temperature outside the middle layer can be made as high as possible above the temperature at which volatiles are deposited or crystallized, so that volatiles are deposited as much as possible in the outer layer rather than the middle layer, thereby maintaining a good thermal insulation effect of the middle layer.

[0205] In some embodiments, the thickness of the middle layer 2013 is greater than the thickness of the inner layer 2011 and the thickness of the outer layer 2012. By setting the thickness of the middle layer greater than the thickness of the inner layer and the thickness of the outer layer, it is ensured that when the insulation effect changes due to loss of the inner layer or impurity deposition on the outer layer, the middle layer can maintain a good and stable insulation effect, reducing the impact of loss of the inner layer and impurity deposition on the insulation performance of the entire insulation device, improving the stability of the insulation performance, and when the inner layer becomes thin due to loss and needs to be replaced, the middle layer can play a supporting role, thereby improving the structural stability of the insulation device.

[0206] In some embodiments, taking into account the replacement cost and actual thermal insulation effect during the actual production process, the thickness of the outer layer 2012 needs to be set within a certain thickness range. In some embodiments, the thickness of the outer layer 2012 can be within the range of 7mm-42mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 10mm-40mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 12mm-38mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 15mm-35mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 17mm-33mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 20mm-30mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 22mm-28mm. In some embodiments, the thickness of the outer layer 2012 can be within the range of 25mm-27mm.

[0207] In some embodiments, in light of the above, and taking into account the overall maintenance cost and insulation effect of the insulation device, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be set within a certain range. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 50 mm to 200 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 60 mm to 190 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 70 mm to 180 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 80 mm to 170 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 90 mm to 160 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 100 mm to 150 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 110 mm to 140 mm. In some embodiments, the total thickness of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 120 mm to 130 mm.

[0208] In some embodiments, in combination with the above, taking into account the overall maintenance cost and insulation effect of the insulation device, the thickness ratio of the inner layer 2011 to the middle layer 2013 needs to be set within a certain range. In some embodiments, the thickness ratio of the inner layer 2011 to the middle layer 2013 can be in the range of 1:2-1:10. In some embodiments, the thickness ratio of the inner layer 2011 to the middle layer 2013 can be in the range of 1:3-1:9. In some embodiments, the thickness ratio of the inner layer 2011 to the middle layer 2013 can be in the range of 1:4-1:8. In some embodiments, the thickness ratio of the inner layer 2011 to the middle layer 2013 can be in the range of 1:5-1:7. In some embodiments, the thickness ratio of the inner layer 2011 to the middle layer 2013 can be in the range of 1:6-1:6.

[0209] In some embodiments, in light of the above, and taking into account the overall maintenance cost and insulation effect of the insulation device, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be set within a certain range. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 2:0.5-10:3. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 3:0.5-9:3. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 4:0.5-8:3. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 5:0.5-7:3. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 6:0.5-6:3. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be within a range of 2:1-10:2.5. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be in the range of 2:1.5-10:2. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be in the range of 2:2-10:1.5. In some embodiments, the thickness ratio of the middle layer 2013 to the outer layer 2012 may be in the range of 2:3-10:1.

[0210] In some embodiments, in combination with the above, taking into account the overall maintenance cost and thermal insulation effect of the thermal insulation device, the thickness ratio of the inner layer 2011 to the outer layer 2012 needs to be set within a certain range. In some embodiments, the thickness ratio of the inner layer 2011 to the outer layer 2012 can be in the range of 1:0.5-1:3. In some embodiments, the thickness ratio of the inner layer 2011 to the outer layer 2012 can be in the range of 1:1-1:2.5. In some embodiments, the thickness ratio of the inner layer 2011 to the outer layer 2012 can be in the range of 1:1.5-1:2. In some embodiments, the thickness ratio of the inner layer 2011 to the outer layer 2012 can be in the range of 1:2-1:1.5. In some embodiments, the thickness ratio of the inner layer 2011 to the outer layer 2012 can be in the range of 1:3-1:1.

[0211] In some embodiments, in light of the above, and taking into account the overall maintenance cost and insulation effect of the thermal insulation device, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be set within a certain range. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 1:2:0.5 to 1:10:3. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 1:2:1 to 1:10:2.5. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 1:2:1.5 to 1:10:2. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be within a range of 1:2:2 to 1:10:1.5. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 1:2:3 to 1:10:1. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 1:3:0.5 to 1:9:3. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 1:4:0.5 to 1:8:3. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 1:5:0.5 to 1:7:3. In some embodiments, the thickness ratio of the inner layer 2011, the middle layer 2013, and the outer layer 2012 may be in the range of 1:6:0.5 to 1:6:3.

[0212] In some embodiments, the material of the inner layer 2011 may include graphite felt. By setting the inner layer to be made of graphite felt, the thermal insulation performance can be ensured to be stable and easy to replace.

[0213] In some embodiments, the material of the outer layer 2012 may be different from the material of the inner layer 2011. In some embodiments, the density of the outer layer 2012 is greater than the density of the inner layer 2011. In some embodiments, the material of the outer layer 2012 may include at least one of zirconium oxide, aluminum oxide, carbon material, or carbon fiber material.

[0214] By using a relatively dense outer layer material with relatively low thermal conductivity, impurities volatilized by heat can be deposited on the outer layer with minimal impact on the insulation performance of the outer layer, thereby ensuring more stable insulation performance. Furthermore, the outer layer material is less expensive than the inner layer material, which can reduce overall costs.

[0215] In some embodiments, the material of the middle layer 2013 can be the same as or different from that of the inner layer 2011, and can be set according to actual needs or costs. For example, the material of the middle layer 2013 can include graphite felt, ceramic, etc.

[0216] In some embodiments, in order to prevent impurities in the inner, middle and / or outer layers from entering the crucible and causing crystal defects during crystal growth, the impurity rate of the inner, middle and / or outer layer materials needs to be set below a certain amount.

[0217] In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 100 ppm. In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 90 ppm. In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 80 ppm. In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 70 ppm. In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 60 ppm. In some embodiments, the impurity rate of the material of inner layer 2011 may be less than 50 ppm.

[0218] In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 100 ppm. In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 90 ppm. In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 80 ppm. In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 70 ppm. In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 60 ppm. In some embodiments, the impurity rate of the material of the middle layer 2013 may be less than 50 ppm.

[0219] In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 100 ppm. In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 90 ppm. In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 80 ppm. In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 70 ppm. In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 60 ppm. In some embodiments, the impurity rate of the material of outer layer 2012 may be less than 50 ppm.

[0220] Typically, impurity transport within the inner, middle, and / or outer layers is influenced by both temperature gradient and concentration. The vast majority of impurities are transported outward from the heat preservation device, driven by the temperature gradient, while a small amount of impurities diffuse inward toward the crucible, driven by concentration. Therefore, to ensure that minimal impurities enter the crucible and cause crystal defects during crystal growth, the impurity rates of the inner, middle, and / or outer layers (especially the inner layer) must meet a specific relationship.

[0221] In some embodiments, the impurity rate of the inner layer 2011 is the lowest. In some embodiments, the impurity rate of the material of the outer layer 2012 is greater than or equal to the impurity rate of the material of the middle layer 2013. In some embodiments, the impurity rate of the material of the middle layer 2013 is greater than or equal to the impurity rate of the material of the inner layer 2011. In some embodiments, the impurity rate of the material of the outer layer 2012 is greater than or equal to the impurity rate of the material of the middle layer 2013, and greater than or equal to the impurity rate of the material of the inner layer 2011.

[0222] In some embodiments, during the actual crystal growth process, since the inner layer 2011 is arranged close to the outside of the crucible and is at a higher temperature, the impurities in the inner layer 2011 are volatilized by heat, which will cause the inner layer to lose thickness and reduce its thermal insulation performance. Therefore, the inner layer 2011 can be designed as an independent replaceable structure to facilitate subsequent replacement. In addition, combined with the above, since an axial temperature gradient is required during the crystal growth process, the temperature at different axial positions is different, and the required thermal insulation performance will also be different. Therefore, the inner layer 2011 can be designed with a structure with different axial thicknesses according to the temperature gradient, which can maintain a good thermal insulation effect at different axial positions, and facilitate targeted maintenance and / or replacement according to the loss conditions at different positions. The specific structure of the inner layer 2011 will be described in detail below with reference to Figures 17A-17D.

[0223] In some embodiments, as shown in Figure 17A, the inner layer 2011 may include at least two insulation sections 111. In some embodiments, at least two insulation sections 111 may be stacked up and down. In some embodiments, the insulation section 111 may be a circular insulation section, and at least two circular insulation sections may be stacked up and down to form a cylindrical structure. In some embodiments, in order to ensure the stability of the inner layer 2011 formed by stacking up and down, the upper and lower contact surfaces of two adjacent insulation sections 111 may be made into a nested structure. For example, for two adjacent insulation sections 111, a protrusion is provided on the lower surface of the upper insulation section 111, and a groove corresponding thereto is provided on the upper surface of the lower insulation section 111, so that after the two adjacent insulation sections are stacked up and down, the fit is tighter and more secure.

[0224] In some embodiments, as shown in Figure 17B, each insulation section 111 may include at least two insulation blocks 112. In some embodiments, at least two insulation blocks 112 may be spliced ​​in blocks along the circumferential direction to form a circular ring structure. In some embodiments, in order to ensure the stability of the insulation section 111 formed by circumferential block splicing, the two contact surfaces of two adjacent insulation blocks 112 may be made into a nested structure. For example, for two adjacent insulation blocks 112, a protrusion is provided on the contact surface of one insulation block 112, and a corresponding groove is provided on the contact surface of the other insulation block that contacts it, so that after the two adjacent insulation blocks are spliced ​​in blocks along the circumferential direction, the fit is tighter and firmer.

[0225] In some embodiments, as shown in Figure 17C, the thickness of the inner layer 2011 along the axial direction may be different. In some embodiments, the thickness of the inner layer 2011 along the axial direction may be designed based on the temperature field distribution (or temperature gradient).

[0226] By setting the thickness of the inner layer to be different along the axial direction (for example, designing the thickness of the inner layer along the axial direction based on the temperature field distribution), the thickness of the inner layer can be adjusted according to the actual temperature field distribution, and targeted replacements can be made according to the loss conditions at different positions of the inner layer (for example, only one or more insulation sections, insulation blocks, etc. are replaced at a time), which can maintain a good insulation effect while saving production costs.

[0227] In some embodiments, as shown in FIG. 17D , the inner layer 2011 has different thicknesses along the axial direction and is provided as at least two heat-insulating sections 111 stacked one above the other.

[0228] In some embodiments, because the structure and thermal insulation performance of the middle layer 2013 change little over time, the middle layer 2013 can be a monolithic structure (e.g., a monolithic thermal insulation tube), which facilitates installation and maintains good thermal insulation. It can also provide support when replacing the inner layer, improving the structural stability of the thermal insulation device.

[0229] In some embodiments, the inner layer 2011 and the middle layer 2013 can be tightly fitted together. In some embodiments, the middle layer 2013 and the outer layer 2012 can be tightly fitted together.

[0230] In some embodiments, as shown in FIG18 , a gap may be provided between the inner layer 2011 and the middle layer 2013. In some embodiments, a gap may be provided between the middle layer 2013 and the outer layer 2012. In some embodiments, the size of the gap between the inner layer 2011 and the middle layer 2013 may be the same as or different from the size of the gap between the middle layer 2013 and the outer layer 2012. In some embodiments, the size of the gap between the inner layer 2011 and the middle layer 2013 may be the shortest distance between the outer side of the inner layer 2011 and the inner side of the middle layer 2013. In some embodiments, the size of the gap between the middle layer 2013 and the outer layer 2012 may be the shortest distance between the outer side of the middle layer 2013 and the inner side of the outer layer 2012.

[0231] In some embodiments, the size of the gap may be in the range of 0 mm to 10 mm. In some embodiments, the size of the gap may be in the range of 1 mm to 9 mm. In some embodiments, the size of the gap may be in the range of 2 mm to 8 mm. In some embodiments, the size of the gap may be in the range of 3 mm to 7 mm. In some embodiments, the size of the gap may be in the range of 4 mm to 6 mm. In some embodiments, the size of the gap may be in the range of 4 mm to 5 mm.

[0232] In some embodiments, as shown in Figure 18 , the gap between the inner layer 2011 and the middle layer 2013 may not be filled with insulation material. In some embodiments, as shown in Figure 18 , the gap between the middle layer 2013 and the outer layer 2012 may not be filled with insulation material.

[0233] Since the thermal conductivity of the air in the gap is lower than that of the solid, the air in the gap can act as an insulation layer to keep the heat insulated. At the same time, since there is a gap between the inner layer, the middle layer and the outer layer, it is convenient to replace the inner layer later.

[0234] In some embodiments, the gap between the inner layer 2011 and the middle layer 2013 can be filled with a thermal insulation material. In some embodiments, the gap between the middle layer 2013 and the outer layer 2012 can be filled with a thermal insulation material. In some embodiments, the thermal insulation material can include one or more of granular material, felt, or brick-like material. In some embodiments, the thermal insulation material can be made of one or more of silicon oxide, aluminum oxide, zirconium oxide, graphite, carbon fiber, or ceramic. In some embodiments, the gap between the inner layer 2011 and the middle layer 2013 can be filled with graphite felt.

[0235] In some embodiments, the gap between the inner layer 2011 and the middle layer 2013 may be filled with a thermal insulation material, while the gap between the middle layer 2013 and the outer layer 2012 may not be filled with a thermal insulation material. In some embodiments, the gap between the inner layer 2011 and the middle layer 2013 may not be filled with a thermal insulation material, while the gap between the middle layer 2013 and the outer layer 2012 may be filled with a thermal insulation material.

[0236] By filling the gaps between the inner and middle layers, as well as the gaps between the middle and outer layers, with insulation material, the insulation performance of the insulation device can be improved, helping to regulate the temperature of the outer layer so that it reaches a preset temperature (for example, the temperature set before crystal growth). Furthermore, because the insulation material (for example, graphite felt) is easily removed, the inner layer can be easily replaced. After the inner layer is replaced, the insulation material can be refilled and reused, saving production costs.

[0237] In some embodiments, as shown in FIG19 , graphite paper 2014 can be filled between middle layer 2013 and outer layer 2012. Because graphite paper has a low porosity, volatiles are less likely to pass through and deposit on its surface. Therefore, graphite paper can serve as a pre-deposition layer for volatiles, reducing the amount of volatiles deposited on the outer layer and thus reducing outer layer losses. Furthermore, graphite paper is easily replaceable and inexpensive, which can improve the stability of thermal insulation performance and reduce production costs.

[0238] In some embodiments, the space between the middle layer 2013 and the outer layer 2012 may be filled with other materials with lower porosity, which is not limited in this specification.

[0239] In some embodiments, the heat preservation device 200 further includes a second heat preservation component 202, which is disposed on the top of the crystal growth device 10. For example, as shown in FIG20, the second heat preservation component 202 can be a top heat preservation layer.

[0240] In some embodiments, the second insulation component 202 includes a stacked structure, and the materials of the stacked structures are the same. For example, the material of the stacked structure can be at least one of graphite felt, zirconium oxide, aluminum oxide, carbon material or carbon fiber material. By setting the stacked structure, the thickness of the second insulation component can be changed with the number of layers of the stacked structure, so that the thickness of the second insulation component can be adjusted according to the actual temperature field distribution, which facilitates the insulation device to maintain a good and stable insulation effect while saving production costs. For example, when it is necessary to increase the thickness of the second insulation component 202, the number of layers of the stacked structure can be increased to achieve an increase in thickness. Similarly, when it is necessary to reduce the thickness of the second insulation component 202, the number of layers of the stacked structure can be reduced to achieve a reduction in thickness.

[0241] In some embodiments, the number of layers of the stacked structure of the second heat preservation component 202 may be 0-15 layers. In some embodiments, the number of layers of the stacked structure of the second heat preservation component 202 may be 0-10 layers. In some embodiments, the number of layers of the stacked structure of the second heat preservation component 202 may be 0-6 layers.

[0242] In some embodiments, the second insulation component 202 may include multiple insulation sections. In some embodiments, the insulation sections of the second insulation component 202 may be annular structures, each insulation section having a different diameter, and the multiple insulation sections may be radially stacked. In some embodiments, adjacent insulation sections in the radially stacked multiple insulation sections abut each other to form the second insulation component 202. By providing multiple insulation sections distributed radially, the thickness (such as the number of layers) can be individually set for each insulation section to regulate the radial temperature distribution within the crystal growth device 10. In some embodiments, the fineness of the regulation of the radial temperature distribution within the growth device 10 can be increased by setting the number of insulation sections distributed radially. In some embodiments, the number of insulation sections distributed radially may be 2-10. In some embodiments, the number of insulation sections distributed radially may be 2-6. In some embodiments, the number of insulation sections distributed radially may be 2-15.

[0243] In some embodiments, the heat preservation device further includes a third heat preservation component 203, and the second heat preservation component 202 is disposed outside the top of the crucible 100. For example, as shown in FIG21, the third heat preservation component 203 can be a pot top heat preservation layer.

[0244] In some embodiments, the third insulation component 203 includes an annular structure or a circular structure. For example, the material of the third insulation component 203 may include one or more of graphite felt, zirconium oxide, aluminum oxide, carbon material, or carbon fiber material. In some embodiments, the insulation effect of the third insulation component 203 can be changed by setting the parameters of the annular structure. In some embodiments, the parameters of the annular structure may include the inner diameter of the annular structure (also known as the inner radius) and the outer diameter of the annular structure (also known as the outer radius). As shown in Figure 6, the inner diameter of the annular structure may refer to the distance from the inner side of the annular structure to the axis of the crucible 100, and the outer diameter of the annular structure may refer to the distance from the outer side of the annular structure to the axis of the crucible 100. By setting the parameters of the annular structure, the insulation effect of the third insulation component can be changed according to the range of the inner and outer diameters of the annular structure. This allows the insulation effect of the third insulation component to be adjusted according to the actual temperature field distribution requirements, facilitates the insulation device to maintain a good and stable insulation effect, and saves production costs. For example, by increasing the outer diameter of the annular structure, the temperature of the inner edge area of ​​the crucible 100 can be increased, and by reducing the inner diameter of the annular structure, the temperature of the center area of ​​the crucible 100 can be increased.

[0245] In some embodiments, the inner diameter r of the annular structure i The range can be 10mm-90mm. In some embodiments, the inner diameter r of the annular structure i The range can be 30mm-90mm. In some embodiments, the inner diameter r of the annular structure i The range can be 30mm-60mm. In some embodiments, the inner diameter r of the annular structure i The range can be 60mm-90mm.

[0246] In some embodiments, the outer diameter r of the annular structure o The range can be 90mm-200mm. In some embodiments, the outer diameter r of the annular structure o The range can be 90mm-150mm. In some embodiments, the outer diameter r of the annular structure o The range can be 90mm-120mm.

[0247] In some embodiments, the outer diameter r of the annular structure o Related to the size of the crucible 100. In some embodiments, the outer diameter r of the annular structure o The ratio of the outer diameter r of the annular structure to the radius of the crucible 100 may be 0.6-1.2. o The ratio of the outer diameter r of the annular structure to the radius of the crucible 100 may be 0.8-1.2. o The ratio of the outer diameter r of the annular structure to the radius of the crucible 100 may be 0.6-1.o The ratio to the radius of the crucible 100 may be 0.6-0.8.

[0248] In some embodiments, the inner diameter r of the annular structure i The ratio of the inner diameter to the outer diameter can be in the range of 0.1-0.8. In some embodiments, the inner diameter r of the annular structure is i With outer diameter r o The ratio range of can be 0.3-0.8. In some embodiments, the inner diameter r of the annular structure i With outer diameter r o The ratio can range from 0.5 to 0.8.

[0249] In some embodiments, the ratio of the inner diameter of the annular structure to the radius of the crucible 100 may be in the range of 0.1-0.9. In some embodiments, the ratio of the inner diameter of the annular structure to the radius of the crucible 100 may be in the range of 0.1-0.8. In some embodiments, the ratio of the inner diameter of the annular structure to the radius of the crucible 100 may be in the range of 0.3-0.8.

[0250] The basic concepts have been described above. It will be apparent to those skilled in the art that the detailed disclosure above is merely illustrative and does not limit 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 and remain within the spirit and scope of the exemplary embodiments of the present application.

[0251] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0252] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0253] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other variations may also fall within the scope of this application. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this application may be considered consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly introduced and described in this application.

Claims

1. A crystal growth apparatus comprising: A crucible comprising a raw material cavity for placing raw materials and a growth cavity for crystal growth; The heat preservation device is arranged on at least one side surface outside the crucible.

2. The crystal growth apparatus according to claim 1, wherein The crucible comprises an upper cover, which comprises a cover body and a seed crystal holder, and the seed crystal holder is detachably connected to the cover body.

3. The crystal growth apparatus according to claim 2, wherein The seed crystal holder includes a connecting structure, and the connecting structure is arranged in a central area of ​​a side of the seed crystal holder close to the cover body.

4. The crystal growth apparatus according to claim 2, wherein The thickness of the seed crystal holder is 2 mm to 10 mm.

5. The crystal growth apparatus according to claim 2, wherein The two surfaces of the seed crystal holder in contact with the cover body include concave and convex structures that match each other.

6. The crystal growth apparatus according to claim 2, wherein The seed crystal holder includes a separation groove for separating the seed crystals on the seed crystal holder.

7. The crystal growth apparatus according to claim 6, wherein The separation groove is a circumferential groove, and the circumferential groove is arranged on the outer circumference of a side away from the cover body.

8. The crystal growth apparatus according to claim 7, wherein The ratio of the depth of the circumferential groove in the radial direction to the radius of the seed crystal holder is in the range of 0.028-0.

042.

9. The crystal growth apparatus according to claim 7, wherein The depth of the circumferential groove in the radial direction is 2 mm to 4 mm, and the height of the circumferential groove in the axial direction is 0.5 mm to 1.5 mm.

10. The crystal growth apparatus according to claim 1, wherein The crucible includes a flow guiding device disposed between the raw material chamber and the growth chamber, wherein the flow guiding device includes a first flow guiding surface inclined toward the bottom surface of the raw material chamber.

11. The crystal growth apparatus according to claim 10, wherein The flow guiding device includes a flow guiding groove, which is a groove arranged on the outer periphery of the flow guiding device.

12. The crystal growth apparatus according to claim 11, wherein The guide groove includes a second guide surface that is parallel or substantially parallel to the first guide surface, and a guide wall is formed between the first guide surface and the second guide surface.

13. The crystal growth apparatus according to claim 12, wherein The flow guiding device further includes a supporting wall, which radially connects the flow guiding wall and the outer peripheral wall of the crucible.

14. The crystal growth apparatus according to claim 12, wherein The thickness of the guide wall is 10mm-60mm.

15. The crystal growth apparatus according to claim 12, wherein The height of the guide groove ranges from 20 mm to 40 mm.

16. The crystal growth apparatus according to claim 12, wherein The ratio of the thickness of the guide wall to the height of the guide groove is in the range of 0.2-1.

5.

17. The crystal growth apparatus according to claim 13, wherein The thickness of the support wall ranges from 10 mm to 60 mm.

18. The crystal growth apparatus according to claim 13, wherein The ratio of the thickness of the guide wall to the thickness of the support wall is in the range of 0.8-1.

2.

19. The crystal growth apparatus according to claim 1, wherein The crystal growth equipment also includes a furnace chamber and a temperature measuring structure. The crucible is arranged in the furnace chamber. The temperature measuring structure includes a temperature measuring cavity and a temperature measuring window. The temperature measuring cavity includes a first cavity section, a main body and a second cavity section. The temperature measuring window is arranged in the first cavity section, and the second cavity section is connected to the furnace chamber.

20. The crystal growth apparatus according to claim 19, wherein The diameter of the main body portion is smaller than the diameter of the furnace cavity.

21. The crystal growth apparatus according to claim 19, wherein The diameter of the first cavity segment and / or the second cavity segment is smaller than the diameter of the main body portion.

22. The crystal growth apparatus according to claim 19, wherein The temperature measurement structure further includes an air inlet and an air outlet, wherein the air inlet is connected to the first cavity section, and the air outlet is connected to the second cavity section.

23. The crystal growth apparatus according to claim 22, wherein The diameter of the air outlet is smaller than the diameter of the air inlet.

24. The crystal growth apparatus according to claim 19, wherein The temperature measurement structure further includes a cooler, which is arranged in the second cavity section.

25. The crystal growth apparatus according to claim 19, wherein The temperature measurement structure further includes a deposition chamber, which is communicated with the furnace chamber.

26. The crystal growth apparatus according to claim 25, wherein The temperature in the deposition chamber is lower than the temperature in the furnace chamber.

27. The crystal growth apparatus according to claim 19, wherein The temperature measurement structure further includes a deposition cavity, which is communicated with the second cavity section.

28. The crystal growth apparatus according to claim 27, wherein The temperature in the deposition chamber is lower than the temperature in the furnace chamber and the temperature in the temperature measurement chamber, and the pressure in the deposition chamber is lower than the pressure in the temperature measurement chamber.

29. The crystal growth apparatus according to claim 1, wherein The heat preservation device includes a first heat preservation component, and the first heat preservation component includes: an inner layer, wherein the thickness of the inner layer meets a preset condition; an outer layer, wherein the material of the outer layer is different from the material of the inner layer; A middle layer is located between the inner layer and the outer layer.

30. The crystal growth apparatus according to claim 29, wherein The first heat-insulating component is at least arranged on the peripheral side of the crucible.

31. The crystal growth apparatus according to claim 29, wherein The thickness of the inner layer ranges from 4 mm to 57 mm.

32. The crystal growth apparatus according to claim 29, wherein The thickness of the middle layer ranges from 28 mm to 143 mm.

33. The crystal growth apparatus according to claim 29, wherein The thickness of the middle layer is greater than the thickness of the inner layer and the thickness of the outer layer.

34. The crystal growth apparatus according to claim 29, wherein The thickness ratio of the inner layer to the middle layer is between 1:2 and 1:

10.

35. The crystal growth apparatus according to claim 29, wherein The thickness ratio of the middle layer to the outer layer is between 2:0.5 and 10:

3.

36. The crystal growth apparatus according to claim 29, wherein The thickness ratio of the inner layer to the outer layer is between 1:0.5 and 1:

3.

37. The crystal growth apparatus according to claim 30, wherein The inner layer includes at least two heat-insulating sections, and the at least two heat-insulating sections are stacked up and down.

38. The crystal growth apparatus according to claim 30, wherein The thickness of the inner layer varies along the axial direction.

39. The crystal growth apparatus according to claim 29, wherein The material of the inner layer includes graphite felt.

40. The crystal growth apparatus according to claim 29, wherein The material of the outer layer includes at least one of zirconium oxide, aluminum oxide, carbon material or carbon fiber material.

41. The crystal growth apparatus according to claim 29, wherein Graphite paper is filled between the middle layer and the outer layer.

42. The crystal growth apparatus according to claim 29, wherein The heat preservation device further includes a second heat preservation component, which is arranged on the top of the crystal growth equipment.

43. The crystal growth apparatus according to claim 42, wherein The second heat-insulating layer includes a stacked structure, and the stacked structure is made of the same material.

44. The crystal growth apparatus according to claim 42, wherein The heat preservation device further includes a third heat preservation component, and the third heat preservation component includes an annular structure or a circular structure.

45. The crystal growth apparatus according to claim 44, wherein The inner diameter of the annular structure ranges from 10 mm to 90 mm.

46. ​​The crystal growth apparatus of claim 44, wherein: The ratio of the outer diameter of the annular structure to the radius of the crucible is 0.6-1.

2.

47. The crystal growth apparatus of claim 44, wherein: The ratio of the inner diameter to the outer diameter of the annular structure is in the range of 0.1-0.

8.

48. The crystal growth apparatus of claim 44, wherein: The ratio of the inner diameter of the annular structure to the radius of the crucible is in the range of 0.1-0.9.

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