A silicon carbide crystal sustainable growth apparatus and method

Abstract

The embodiment of the present application provides a silicon carbide crystal sustainable growth device and method, and relates to the technical field of silicon carbide crystal growth. The silicon carbide crystal sustainable growth method is applied to the silicon carbide crystal sustainable growth device. The silicon carbide crystal sustainable growth device comprises a crucible, a heating assembly, a first lifting piece and a second lifting piece. Through the setting of the first lifting piece, the loading part and the second lifting piece, the crystal growth raw material which has not been completely sublimated in the raw material area can be gradually pushed into the high-temperature area, so that the continuous supply and dynamic sublimation of the raw material are realized. The growth interface of the silicon carbide crystal can always be maintained in a suitable temperature range, and the sustainability of the silicon carbide crystal growth is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide crystal growth technology, and more specifically, to a device and method for the sustainable growth of silicon carbide crystals. Background Technology

[0002] Silicon carbide (SiC), as an emerging core material for third-generation semiconductors, possesses excellent properties such as a wide bandgap, high critical breakdown electric field strength, high electron mobility, and good radiation resistance and chemical stability. This makes it an important substrate wafer material with wide applications and shows promising application prospects in fields such as aerospace devices, new energy vehicles, rail transportation, and home appliances.

[0003] In some silicon carbide crystal growth devices of related technologies, it is difficult to achieve continuous growth of silicon carbide. Summary of the Invention

[0004] The present invention aims to provide a device and method for the sustainable growth of silicon carbide crystals, which can improve the sustainability of silicon carbide crystal growth.

[0005] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a device for the sustainable growth of silicon carbide crystals, comprising: The crucible has a flow guide plate on its inner circumferential wall. The outer circumference of the flow guide plate is fitted to the inner circumferential wall of the crucible and fixedly installed inside the crucible. The bottom of the crucible also has a receiving part. The outer circumferential wall of the receiving part is fitted to the inner circumferential wall of the crucible. The receiving part and the flow guide plate together define a raw material area for filling the crystal growth raw material. The flow guide plate has a vent hole. The crucible has a discharge port that communicates with the raw material area on its circumferential wall. The top of the crucible has an opening. The heating component is located outside the crucible and opposite to the outer wall of the crucible. The bottom of the heating component and the bottom of the crucible have a preset distance in the axial direction. The first lifting component has its driving end extending into the crucible and connecting to the mounting part, so as to drive the mounting part to move along the axial direction of the crucible. The second lifting component has a driving end connected to a crucible cover, on which a seed crystal is fixedly installed. The seed crystal can extend into or out of the crucible through an opening. The second lifting component is used to drive the crucible cover to move along the axial direction of the crucible.

[0006] In an optional embodiment, the guide plate is conical in shape, the distance between the guide plate and the bottom of the crucible gradually decreases in the direction close to the center of the crucible, and the discharge port is located between the guide plate and the bottom plate of the crucible.

[0007] In an optional embodiment, the guide plate is a porous graphite plate or a porous tantalum carbide plate.

[0008] In an optional embodiment, a flow equalization component is further included, which is fixedly disposed inside the crucible. The flow equalization component is located above the flow guide plate and includes a flow equalization plate having a plurality of flow equalization holes.

[0009] In an optional embodiment, the flow equalization assembly includes a plurality of flow equalization plates spaced apart along an axial direction. The plurality of flow equalization plates include a first flow equalization plate and a second flow equalization plate. The first flow equalization plate is provided with a plurality of first flow equalization holes, and the second flow equalization plate is provided with a plurality of second flow equalization holes. The plurality of first flow equalization holes and the plurality of second flow equalization holes are misaligned in the axial direction.

[0010] In an optional embodiment, the flow equalization plate is a porous graphite plate or a porous tantalum carbide plate.

[0011] In an optional embodiment, a discharge component is further provided on the outside of the crucible. The discharge component includes a first discharge section and a second discharge section connected at an angle. The extension direction of the first discharge section is parallel to the radial direction of the crucible, and the second discharge section extends downward. The first discharge section is provided with a first discharge channel communicating with the discharge port, and the second discharge section is provided with a second discharge channel communicating with the first discharge channel and extending downward. The heating assembly includes a first heating element and a second heating element. The first heating element is located above the first discharge section, and the second heating element is located below the first discharge section and between the second discharge section and the crucible.

[0012] In an optional embodiment, a receiving section is further included, which has a receiving cavity, and a second discharge section extends into the receiving cavity. The receiving cavity has a guide slope, the height of which gradually increases in the direction close to the crucible, and the guide slope is opposite to the outlet of the second discharge channel. And / or, the number of discharge components and discharge ports are both two and are set in a one-to-one correspondence. The two discharge ports, the two discharge components, and the raw material area are all set symmetrically about the preset plane.

[0013] In an optional embodiment, it further includes a heat-preserving furnace for placing the crucible. The heat-preserving furnace has a first heat-preserving cavity and a second heat-preserving cavity that are sequentially arranged and communicate with each other along the axial direction. The first heat-preserving cavity is located below the second heat-preserving cavity. The radial dimension of the first heat-preserving cavity is smaller than the radial dimension of the second heat-preserving cavity. The lower end of the crucible is housed in the first heat-preserving cavity. The heating component is located in the second heat-preserving cavity. The driving end of the first lifting component extends sequentially into the first heat-preserving cavity and the crucible to connect with the receiving part. The top of the holding furnace is provided with a top insulation part, which abuts against the top of the crucible and is provided with a third insulation cavity. The third insulation cavity is connected to the second insulation cavity and is connected to the opening. The driving end of the second lifting component extends into the third insulation cavity and is connected to the crucible cover to drive the crucible cover to move axially in the crucible or the third insulation cavity. The outer side of the top insulation part is provided with a heating component.

[0014] In a second aspect, the present invention provides a method for the sustainable growth of silicon carbide crystals, applied to the silicon carbide crystal sustainable growth apparatus of any of the foregoing embodiments, the method comprising: Activate the first lifting component to move the mounting part upward, so that some of the crystal growth material in the raw material area is discharged from the discharge port. The second lifting component is activated to move the crucible lid upwards, thereby bringing the growth interface of the silicon carbide crystal within a preset temperature range.

[0015] The beneficial effects provided by the embodiments of the present invention include: the embodiments of the present invention provide a silicon carbide crystal sustainable growth apparatus and method. The silicon carbide crystal sustainable growth method is applied to the silicon carbide crystal sustainable growth apparatus, which includes a crucible, a heating assembly, a first lifting component, and a second lifting component. A guide plate is provided on the inner peripheral wall of the crucible, and the outer periphery of the guide plate is fitted and fixedly installed inside the crucible. A receiving part is also provided at the bottom of the crucible, and the outer peripheral wall of the receiving part is fitted with the inner peripheral wall of the crucible. The receiving part and the guide plate together define a raw material area for filling the crystal growth material. The guide plate has a vent, and a discharge port communicating with the raw material area is opened on the peripheral wall of the crucible. An opening is opened on the top of the crucible. The driving end of the first lifting component extends into the crucible and connects to the receiving part, thereby driving the receiving part to move along the axis of the crucible. The driving end of the second lifting component is connected to the crucible lid, on which a seed crystal is fixedly mounted. The seed crystal can extend into or move out of the crucible through an opening. The second lifting component is used to drive the crucible lid to move along the axis of the crucible. Through the arrangement of the first and second lifting components, the incompletely sublimated crystal growth material in the raw material zone can be gradually pushed into the high-temperature zone, achieving continuous supply and dynamic sublimation of the raw material. It also ensures that the growth interface of the silicon carbide crystal is always maintained within a suitable temperature range, effectively improving the sustainability of silicon carbide crystal growth. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the silicon carbide crystal sustainable growth device provided in this embodiment from a first-view perspective.

[0018] Icons: 1-Silicon carbide crystal sustainable growth device; 100-Crucible; 110-Guide plate; 111-Ventilation hole; 120-Crucible lid; 130-Seed crystal; 140-Discharge port; 151-First discharge section; 1511-First discharge channel; 152-Second discharge section; 1521-Second discharge channel; 160-Loading section; 200-Heating assembly; 210-First heating element; 220-Second heating element Components; 300-First lifting component; 400-Second lifting component; 500-Flow equalization assembly; 510-First flow equalization plate; 511-First flow equalization hole; 520-Second flow equalization plate; 521-Second flow equalization hole; 600-Insulation furnace; 610-First insulation cavity; 620-Second insulation cavity; 630-Top insulation part; 631-Third insulation cavity; 640-Receiving part; 641-Receiving cavity; 642-Guide slope. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] The following describes in detail, with reference to the accompanying patent drawings, the specific structure of a silicon carbide crystal sustainable growth device provided by an embodiment of the present invention and the corresponding technical effects it brings.

[0026] Please refer to Figure 1 The silicon carbide crystal sustainable growth device 1 provided in this embodiment of the invention includes a crucible 100, a heating component 200, a first lifting component 300 and a second lifting component 400.

[0027] A flow guide plate 110 is provided on the inner peripheral wall of the crucible 100. The outer periphery of the flow guide plate 110 is fitted with the inner peripheral wall of the crucible 100 and fixedly installed inside the crucible 100. A receiving part 160 is also provided at the bottom of the crucible 100. The outer peripheral wall of the receiving part 160 is fitted with the inner peripheral wall of the crucible 100. The receiving part 160 and the flow guide plate 110 together define a raw material area for filling the crystal growth raw material. The flow guide plate 110 has a vent hole 111. A discharge port 140 communicating with the raw material area is opened on the peripheral wall of the crucible 100. An opening is opened on the top of the crucible 100.

[0028] The heating component 200 is located outside the crucible 100 and opposite to the outer wall of the crucible 100. The bottom of the heating component 200 and the bottom of the crucible 100 have a preset distance in the axial direction.

[0029] The driving end of the first lifting component 300 extends into the crucible 100 and connects with the mounting part 160 to drive the mounting part 160 to move along the axial direction of the crucible 100.

[0030] The driving end of the second lifting component 400 is connected to the crucible cover 120, and a seed crystal 130 is fixedly disposed on the crucible cover 120. The seed crystal 130 can extend into or move out of the crucible 100 through the opening. The second lifting component 400 is used to drive the crucible cover 120 to move along the axial direction of the crucible 100.

[0031] It should be noted that the vent of the guide plate 110 in this embodiment is not for discharging material, but for allowing the sublimated crystal growth atmosphere to pass through the guide plate 110, thereby enabling the growth of silicon carbide crystals on the seed crystal 130.

[0032] Understandably, the heating component 200 is located outside the crucible 100 and is arranged opposite to the outer wall of the crucible 100. Its bottom and the bottom of the crucible 100 maintain a preset distance in the axial direction. The preset gap between the bottom of the heating component 200 and the bottom of the crucible 100 makes the bottom area of ​​the crucible 100 (the area inside the crucible 100 located below the bottom of the heating component 200) a relatively low temperature zone, while the area inside the crucible 100 located above the bottom of the heating component 200 forms a high-temperature sublimation zone. The driving end of the first lifting component 300 can drive the mounting part 160 to move upward along the axial direction of the crucible 100, thereby gradually pushing the incompletely sublimated crystal growth material in the raw material area into the high-temperature zone, realizing a continuous supply of raw materials.

[0033] During the process of pushing the crystal growth material upward, due to the setting of the guide plate 110, some of the crystal growth material that is in contact with the bottom of the guide plate 110 will be squeezed towards the discharge port 140, which can make some carbonized powder near the edge of the crucible 100 discharged from the discharge port 140.

[0034] Furthermore, the driving end of the second lifting component 400 is connected to a crucible cover 120, on which a seed crystal 130 is fixedly disposed. The seed crystal 130 can move along the axial direction through the opening at the top of the crucible 100. When the second lifting component 400 moves the crucible cover 120 along the axial direction, it essentially controls the longitudinal position of the seed crystal 130 within the crucible 100, thereby ensuring that the growth interface of the silicon carbide crystal is always maintained within a suitable temperature range that meets the requirements of crystallization kinetics. This effectively improves the sustainability of silicon carbide crystal growth.

[0035] Specifically, in this embodiment, the guide plate 110 is conical in shape, the distance between the guide plate 110 and the bottom of the crucible 100 gradually decreases in the direction close to the center of the crucible 100, and the discharge port 140 is located between the guide plate 110 and the bottom plate of the crucible 100.

[0036] In this embodiment, by constructing the guide plate 110 into a conical structure with a low center and high edges, it is beneficial to guide the crystal growth material along the back of the guide plate 110 to the discharge port 140. When the first lifting member 300 moves the supporting part 160 upward, the crystal growth material supported by the top of the supporting part 160 is pushed upward. Its bottom edge first contacts the outer peripheral inclined surface of the guide plate 110, and under the action of the pushing force, it slides upward along the inclined surface on the back of the guide plate 110, and finally converges to the vicinity of the discharge path formed by the outer periphery of the guide plate 110 and the inner wall of the crucible 100, and is smoothly discharged from the discharge port 140.

[0037] Optionally, the guide plate 110 is a porous graphite plate or a porous tantalum carbide plate. Understandably, graphite or porous tantalum carbide has good resistance to Si / C vapor erosion, and its porous framework can maintain structural integrity at high temperatures without introducing additional metallic impurities.

[0038] In detail, in this embodiment, the silicon carbide crystal sustainable growth apparatus 1 further includes a heat preservation furnace 600 for placing the crucible 100. The heat preservation furnace 600 has a first heat preservation cavity 610 and a second heat preservation cavity 620 that are sequentially arranged and interconnected along the axial direction. The first heat preservation cavity 610 is located below the second heat preservation cavity 620. The radial dimension of the first heat preservation cavity 610 is smaller than the radial dimension of the second heat preservation cavity 620. The lower end of the crucible 100 is housed in the first heat preservation cavity 610. The heating component 200 is located in the second heat preservation cavity 620. The driving end of the first lifting component 300 extends sequentially into the first heat preservation cavity 610 and the crucible 100 to connect with the receiving part 160.

[0039] Understandably, since part of the crucible 100 is housed within the first insulation cavity 610 and the heating component 200 is located within the second insulation cavity 620, the portion of the crystal growth material located within the first insulation cavity 610 is in a lower temperature range. Furthermore, the first insulation cavity 610, due to its smaller radial dimension, has a relatively concentrated heat capacity and a faster thermal response, thus forming a tighter low-temperature enclosure for the lower part of the crucible 100 (especially the supporting portion 160 and the underlying layer of the crystal growth material it supports). The second insulation cavity 620, with its larger radial dimension, provides ample space for the installation and heat dissipation of the heating component 200, and its larger cavity volume enables a more uniform heat distribution, thereby creating a stable and adjustable high-temperature sublimation zone in the upper part of the crucible 100.

[0040] A top insulation section 630 is provided above the heat preservation furnace 600. The top insulation section abuts against the top of the crucible 100 and is provided with a third insulation cavity 631. The third insulation cavity 631 is connected to the second insulation cavity 620 and is connected to the opening. The driving end of the second lifting member 400 extends into the third insulation cavity 631 and is connected to the crucible cover 120 to drive the crucible cover 120 to move axially within the crucible 100 or the third insulation cavity 631. A heating assembly 200 is provided on the outside of the top insulation section 630.

[0041] The third heat-insulating cavity 631 essentially constitutes a heat-sealed channel extending along the axis of the crucible 100, which not only ensures the temperature stability of the path along which the seed crystal 130 moves up and down with the crucible cover 120, but also prevents the high-temperature reaction atmosphere from escaping from the opening or the reverse intrusion of external impurity gases.

[0042] Specifically, a discharge component is also provided on the outside of the crucible 100, which includes a first discharge section 151 and a second discharge section 152 connected at an angle.

[0043] Optionally, the extension direction of the first discharge section 151 can be parallel to the radial direction of the crucible 100. Of course, in some embodiments, the extension direction of the first discharge section 151 can also be inclined upward. The second discharge section 152 extends downward. The first discharge section 151 is provided with a first discharge channel 1511 communicating with the discharge port 140, and the second discharge section 152 is provided with a second discharge channel 1521 communicating with the first discharge channel 1511 and extending downward.

[0044] In some embodiments, the first discharge channel 1511 may be inclined upward to better receive the material squeezed by the guide plate 110 with a conical surface. Of course, in optional embodiments, the first discharge channel 1511 may also be parallel to the radial direction of the crucible 100, as long as it can ensure that the edge carbon particles squeezed by the bottom wall of the guide plate 110 and the receiving part 160 can be discharged smoothly through the discharge port 140, the first discharge channel 1511 and the second discharge channel 1521.

[0045] In other words, the first discharge section 151 is used to receive the crystal growth raw material discharged from the discharge port 140 on the periphery of the crucible 100, and the raw material is laterally discharged through the first discharge channel 1511 set inside it. The second discharge section 152 extends downward from the end of the first discharge section 151 to form a vertical or nearly vertical second discharge channel 1521, which is used to further guide the raw material to the receiving area below.

[0046] The heating assembly 200 includes a first heating element 210 and a second heating element 220. The first heating element 210 is located above the first discharge section 151, and the second heating element 220 is located below the first discharge section 151 and between the second discharge section 152 and the crucible 100. Specifically, both the first heating element 210 and the second heating element 220 are located within the second insulation cavity 620, and the first heating element 210 is located on the outer side of the top insulation section 630.

[0047] The second heating element 220 is arranged between the second discharge section 152 and the crucible 100, which can effectively prevent crystallization in the first discharge channel 1511 and the second discharge channel 1521.

[0048] Optionally, in this embodiment, the number of discharge components and discharge ports 140 are both two and are set in a one-to-one correspondence. The two discharge ports 140, the two discharge components, and the raw material area are all symmetrically arranged about a preset plane.

[0049] It should be noted that the two discharge components mentioned above can be a ring-shaped, integrated discharge structure, or they can be two separate discharge components symmetrically arranged about a preset plane. Similarly, the two discharge ports 140 can also be two separate discharge ports 140 symmetrically arranged about a preset plane. When the discharge ports 140 are two independent discharge ports 140, in order to facilitate the discharge of the crystal growth raw material, each independent discharge port 140 extends along the circumferential direction of the crucible 100, and the central angle corresponding to the discharge port 140 is greater than 90° and less than 180°.

[0050] Similarly, the two discharge ports 140 mentioned above can also be annular and integral discharge ports 140 structures. That is, the two discharge ports 140 are connected end to end to form an annular discharge outlet. It can be understood that since the two discharge ports 140 in the crucible 100 are connected end to end, the crucible 100 is divided into an upper crucible and a lower crucible by the discharge outlet formed by the two discharge ports 140. In order to ensure that the upper crucible and the lower crucible will not easily move relative to each other, multiple support parts are also provided in the discharge port 140. The multiple support parts are arranged at intervals along the circumference of the crucible 100. The support parts can be integrally formed with the upper crucible and the lower crucible.

[0051] Optionally, in other embodiments, the lower crucible is housed within the first insulation cavity 610, and the upper crucible can be fixedly connected to the top insulation portion 630. For example, the upper crucible is provided with an internal thread, and the top insulation portion 630 is provided with an external thread that connects to the upper crucible's thread to achieve a threaded connection between the two. Alternatively, the top insulation portion 630 is provided with an internal thread, and the upper crucible is provided with an external thread that connects to the top insulation portion 630 to achieve a threaded connection.

[0052] With the above settings, during the process of the first lifting member 300 driving the mounting part 160 to rise, the edge of the crystal growth material in the raw material area can flow relatively evenly from the discharge port 140 to the first discharge channel 1511 and the second discharge channel 1521 of the discharge member.

[0053] Optionally, in some embodiments, the silicon carbide crystal sustainable growth apparatus 1 further includes a receiving section 640, which has a receiving cavity 641. A second discharge section 152 extends into the receiving cavity 641. The receiving cavity 641 has a guide slope 642. The height of the guide slope 642 gradually increases in the direction close to the crucible 100. The guide slope 642 is opposite to the outlet of the second discharge channel 1521.

[0054] Specifically, in this embodiment, both the receiving section 640 and the discharging component are annular structures; that is, the receiving cavity 641 of the receiving section 640 is annular. The first discharging channel 1511 and the second discharging channel 1521 in the discharging component are both annular channels.

[0055] Understandably, the guide slope 642 refers to the inner wall surface with a certain inclination angle set facing the outlet of the second discharge channel 1521. Its function is to first impact the guide slope 642 when the crystal growth raw material is ejected or slides down through the outlet of the second discharge channel 1521 at a certain initial velocity. The lifting trend of the guide slope 642 guides the movement direction of the raw material from vertically downward to obliquely inward or sliding along the slope. The guide slope 642 is opposite to the outlet of the second discharge channel 1521, indicating that the two are in a positive facing relationship in spatial position. This ensures that the raw material contacts the guide slope 642 as soon as it flows out, and also avoids the continuous accumulation of carbonized particles discharged from the crucible 100 in the part of the receiving cavity 641 opposite to the outlet of the second discharge channel 1521.

[0056] Understandably, the material receiving chamber 641 can be used to collect the material discharged from the crucible 100, thus preventing the material discharged from the crucible 100 from polluting the external environment of the crucible 100.

[0057] Specifically, the silicon carbide crystal sustainable growth apparatus 1 in this embodiment also includes a flow equalization component 500 fixedly disposed within the crucible 100. The flow equalization component 500 is located above the flow guide plate 110 and includes a flow equalization plate with multiple flow equalization holes. The multiple flow equalization holes on the flow equalization plate allow the rising airflow to be dispersed and re-rectified as it passes through the flow equalization holes, thereby reducing the airflow velocity gradient and weakening lateral disturbances, and improving the radial uniformity of the crystal growth gas phase.

[0058] Optionally, the flow equalization assembly 500 includes a plurality of flow equalization plates spaced apart along the axial direction. The plurality of flow equalization plates include a first flow equalization plate 510 and a second flow equalization plate 520. The first flow equalization plate 510 is provided with a plurality of first flow equalization holes 511, and the second flow equalization plate 520 is provided with a plurality of second flow equalization holes 521. The plurality of first flow equalization holes 511 and the plurality of second flow equalization holes 521 are misaligned in the axial direction.

[0059] Because the multiple first flow equalization holes 511 on the first flow equalization plate 510 and the multiple second flow equalization holes 521 on the second flow equalization plate 520 are spatially misaligned, the airflow path that originally passed directly upward through the first flow equalization holes 511 is partially blocked or forcibly deflected. The airflow cannot continuously pass through the first flow equalization plate 510 and the second flow equalization plate 520 along the original straight channel, and will undergo lateral diffusion, merging, and remixing in the gap space between the first flow equalization plate 510 and the second flow equalization plate 520. This allows for stepwise disturbance and redistribution of the crystal growth gas phase flowing from bottom to top without significantly increasing airflow resistance. This can weaken excessively high local airflow velocity, suppress transient concentration fluctuations caused by powder slippage, and thus improve the radial uniformity of the crystal growth atmosphere.

[0060] Optionally, the flow equalization plate is a porous graphite plate or a porous tantalum carbide plate. Furthermore, in this embodiment, the flow equalization plate is coaxially arranged with the crucible 100, further improving the flow equalization effect of the flow equalization component 500 on the growth gas phase.

[0061] This invention also provides a method for the sustainable growth of silicon carbide crystals, applied to the aforementioned sustainable growth apparatus 1 for silicon carbide crystals, the method comprising: The first lifting component 300 is activated so that the first lifting component 300 drives the receiving part 160 to move upward so that some of the crystal growth raw materials in the raw material area are discharged from the discharge port 140. The second lifting component 400 is activated so that it moves the crucible cover 120 upward, thereby bringing the growth interface of the silicon carbide crystal within a preset temperature range.

[0062] After the silicon carbide crystal has been in place for a period of time, a large amount of the crystal growth material near the bottom of the raw material area close to the support section 160 has been sublimated and consumed. The remaining raw material gradually moves upward and tends to accumulate loosely. The first lifting component 300 is activated to push the support section 160 upward synchronously. Since the outer peripheral wall of the support section 160 is in contact with the inner peripheral wall of the crucible 100, and together with the guide plate 110 defines the raw material area for filling the crystal growth material, the rise of the support section 160 will squeeze and lift the crystal growth material accumulated above it, so that this part of the raw material moves as a whole to the gap area between the guide plate 110 and the bottom plate of the crucible 100. The guide plate 110 is conical in shape, and the distance between it and the bottom of the crucible 100 gradually decreases in the direction close to the center of the crucible 100, forming an inclined back surface that converges toward the side wall of the crucible 100. This structure can guide the raw material during the lifting process, causing the loose raw material to slide along the back surface of the guide plate 110 and converge to the location of the discharge port 140. Finally, some of the crystal growth raw material is discharged to the outside of the crucible 100 through the discharge port 140.

[0063] As the mounting section 160 moves upward and the silicon carbide crystal on the seed crystal 130 gradually thickens, the growth interface needs to be maintained in the "effective growth temperature zone" with the maximum temperature gradient and suitable supersaturation. This temperature zone is usually located in a specific axial height range in the radially symmetrical high-temperature field formed by the heating component 200. Therefore, the second lifting component 400 is needed to drive the crucible cover 120 and the seed crystal 130 fixed on it to move upward synchronously so that the growth interface is once again in a suitable temperature range with a relatively stable axial position constructed by the heating component 200 and the holding furnace 600.

[0064] In summary, this invention provides a silicon carbide crystal sustainable growth apparatus 1 and method. The silicon carbide crystal sustainable growth method is applied to the silicon carbide crystal sustainable growth apparatus 1, which includes a crucible 100, a heating assembly 200, a first lifting component 300, and a second lifting component 400. A guide plate 110 is provided on the inner peripheral wall of the crucible 100. The outer periphery of the guide plate 110 is fitted to and fixedly installed inside the crucible 100. A receiving portion 160 is also provided at the bottom of the crucible 100. The outer peripheral wall of the receiving portion 160 is fitted to the inner peripheral wall of the crucible 100. The receiving portion 160 and the guide plate 110 together define a raw material area for filling the crystal growth material. The guide plate 110 has a vent. A discharge port 140 communicating with the raw material area is opened on the peripheral wall of the crucible 100. An opening is opened at the top of the crucible 100. The driving end of the first lifting component 300 extends into the crucible 100 and connects to the receiving part 160, thereby driving the receiving part 160 to move along the axial direction of the crucible 100. The driving end of the second lifting component 400 is connected to the crucible cover 120, on which a seed crystal 130 is fixedly disposed. The seed crystal 130 can extend into or move out of the crucible 100 through an opening. The second lifting component 400 is used to drive the crucible cover 120 to move along the axial direction of the crucible 100. Through the arrangement of the first lifting component 300 and the second lifting component 400, the incompletely sublimated crystal growth material in the raw material zone can be gradually pushed into the high-temperature zone, realizing continuous supply and dynamic sublimation of raw materials. It can also keep the growth interface of silicon carbide crystals within a suitable temperature range, effectively improving the sustainability of silicon carbide crystal growth.

[0065] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for the sustainable growth of silicon carbide crystals, characterized in that, include: A crucible (100) has a flow guide plate (110) on its inner peripheral wall. The outer periphery of the flow guide plate (110) is fitted to the inner peripheral wall of the crucible (100) and fixedly installed inside the crucible (100). A receiving part (160) is also provided at the bottom of the crucible (100). The outer peripheral wall of the receiving part (160) is fitted to the inner peripheral wall of the crucible (100). The receiving part (160) and the flow guide plate (110) together define a raw material area for filling crystal growth raw materials. The flow guide plate (110) has a vent hole (111). A discharge port (140) communicating with the raw material area is opened on the peripheral wall of the crucible (100). An opening is opened on the top of the crucible (100). A heating assembly (200) is located outside the crucible (100) and opposite to the outer wall of the crucible (100). The bottom of the heating assembly (200) and the bottom of the crucible (100) have a predetermined distance in the axial direction. The first lifting component (300) has its driving end extending into the crucible (100) and connected to the mounting portion (160) to drive the mounting portion (160) to move along the axial direction of the crucible (100). The second lifting component (400) is connected to a crucible cover (120) at its driving end. A seed crystal (130) is fixedly disposed on the crucible cover (120). The seed crystal (130) can extend into or out of the crucible (100) through the opening. The second lifting component (400) is used to drive the crucible cover (120) to move along the axial direction of the crucible (100).

2. The silicon carbide crystal sustainable growth apparatus according to claim 1, characterized in that: The guide plate (110) is conical in shape, and the distance between the guide plate (110) and the bottom of the crucible (100) gradually decreases in the direction close to the center of the crucible (100). The discharge port (140) is located between the guide plate (110) and the bottom plate of the crucible (100).

3. The silicon carbide crystal sustainable growth apparatus according to claim 1, characterized in that: The guide plate (110) is a porous graphite plate or a porous tantalum carbide plate.

4. The silicon carbide crystal sustainable growth apparatus according to claim 1, characterized in that: It also includes a flow equalization component (500) fixedly disposed in the crucible (100), the flow equalization component (500) being located above the flow guide plate (110), the flow equalization component (500) including a flow equalization plate having a plurality of flow equalization holes.

5. The silicon carbide crystal sustainable growth apparatus according to claim 4, characterized in that: The flow equalization assembly (500) includes a plurality of flow equalization plates spaced apart along the axial direction. The plurality of flow equalization plates include a first flow equalization plate (510) and a second flow equalization plate (520). The first flow equalization plate (510) is provided with a plurality of first flow equalization holes (511), and the second flow equalization plate (520) is provided with a plurality of second flow equalization holes (521). The plurality of first flow equalization holes (511) and the plurality of second flow equalization holes (521) are misaligned in the axial direction.

6. The silicon carbide crystal sustainable growth apparatus according to claim 4, characterized in that: The flow equalization plate is a porous graphite plate or a porous tantalum carbide plate.

7. The silicon carbide crystal sustainable growth apparatus according to claim 1, characterized in that: The crucible (100) is also provided with a discharge component on its outer side. The discharge component includes a first discharge section (151) and a second discharge section (152) connected at an angle. The extension direction of the first discharge section (151) is parallel to the radial direction of the crucible (100). The second discharge section (152) extends downward. The first discharge section (151) is provided with a first discharge channel (1511) communicating with the discharge port (140). The second discharge section (152) is provided with a second discharge channel (1521) communicating with the first discharge channel (1511) and extending downward. The heating assembly (200) includes a first heating element (210) and a second heating element (220). The first heating element (210) is located above the first discharge section (151). The second heating element (220) is located below the first discharge section (151) and between the second discharge section (152) and the crucible (100).

8. The silicon carbide crystal sustainable growth apparatus according to claim 7, characterized in that: It also includes a receiving section (640), which has a receiving cavity (641). The second discharge section (152) extends into the receiving cavity (641). The receiving cavity (641) has a guide slope (642). The height of the guide slope (642) gradually increases in the direction close to the crucible (100). The guide slope (642) is opposite to the outlet of the second discharge channel (1521). And / or, the number of the discharge components and the discharge ports (140) are both two and are set in a one-to-one correspondence. The two discharge ports (140), the two discharge components and the raw material area are all symmetrically arranged about a preset plane.

9. The silicon carbide crystal sustainable growth apparatus according to claim 1, characterized in that: It also includes a heat preservation furnace (600) for placing the crucible (100), the heat preservation furnace (600) having a first heat preservation cavity (610) and a second heat preservation cavity (620) arranged sequentially along the axial direction and communicating with each other. The first heat preservation cavity (610) is located below the second heat preservation cavity (620). The radial dimension of the first heat preservation cavity (610) is smaller than the radial dimension of the second heat preservation cavity (620). The lower end of the crucible (100) is accommodated in the first heat preservation cavity (610). The heating component (200) is located in the second heat preservation cavity (620). The driving end of the first lifting component (300) extends sequentially into the first heat preservation cavity (610) and the crucible (100) to connect with the mounting part (160). A top insulation part (630) is provided above the heat preservation furnace (600). The top insulation part (630) abuts against the top of the crucible (100) and is provided with a third insulation cavity (631). The third insulation cavity (631) is connected to the second insulation cavity (620) and is connected to the opening. The driving end of the second lifting member (400) extends into the third insulation cavity (631) and is connected to the crucible cover (120) to drive the crucible cover (120) to move along the axial direction in the crucible (100) or the third insulation cavity (631). The heating component (200) is provided on the outside of the top insulation part (630).

10. A method for the sustainable growth of silicon carbide crystals, characterized in that, The method, applied to the silicon carbide crystal sustainable growth apparatus according to any one of claims 1-9, comprises: The first lifting component (300) is activated so that the first lifting component (300) drives the receiving part (160) to move upward so that some of the crystal growth raw materials in the raw material area are discharged from the discharge port (140); The second lifting component (400) is activated so that it moves the crucible cover (120) upward, thereby bringing the growth interface of the silicon carbide crystal within a preset temperature range.

Images