A flow guide device, a crystal growth device, and a crystal growth method

Abstract

The embodiments of the present specification disclose a flow guide device, a crystal growth device and a crystal growth method. The flow guide device comprises a flow guide side wall, the flow guide side wall forms a flow guide space around a first direction; a partition plate is arranged in the flow guide space, and the flow guide space is divided into a first space and a second space along the first direction; the crystal growth device comprises the flow guide device; a crucible is used for containing the raw material liquid; a tray is used for supporting a seed crystal, and the crystal is grown on the growth surface of the seed crystal; and the crystal growth method comprises growing the crystal by using the crystal growth device.

Description

Technical Field

[0001] This specification relates to crystal growth technology, and in particular to a flow guiding device, a crystal growth apparatus, and a crystal growth method. Background Technology

[0002] In solution-grown silicon carbide crystals, off-axis seed crystals are typically used to suppress the extension of inherent defects in the seed crystal (e.g., micropipe defects and various dislocations) into the growing crystal. This is because off-axis seed crystals provide sufficient steps and achieve efficient defect transformation. The steps on the surface of an off-axis seed crystal always extend in a single direction, while the solution transport direction generally flows from the center of the seed crystal growth surface outwards. This results in some steps flowing parallel to the solution flow direction, while others flow in the opposite direction. Consequently, the crystal surface grown in the region where the step flow direction is parallel to the solution flow direction is smooth, while the crystal surface grown in the region where the step flow direction is parallel to the solution flow direction is very rough.

[0003] Therefore, it is necessary to provide an improved flow guiding device, crystal growth device, and crystal growth method to improve the crystal surface quality. Summary of the Invention

[0004] One embodiment of this specification provides a flow guiding device for adjusting the flow direction of a raw material solution during crystal growth. The flow guiding device includes: a flow guiding sidewall forming a flow guiding space around a first direction; and a partition plate disposed in the flow guiding space, dividing the flow guiding space into a first space and a second space along the first direction. The flow guiding sidewall includes a first sidewall and a second sidewall. The inner wall of the first sidewall protrudes outward from the flow guiding space, and the inner wall of the second sidewall has an arc-shaped structure located in the first space. A first end of the partition plate is transitionally connected to the first end of the arc-shaped structure, and a second end of the arc-shaped structure extends away from the first sidewall. The second end of the partition plate opposite to the first end forms an opening with the inner wall of the first sidewall. The raw material solution enters the first space from the second space through the opening along the inner wall of the first sidewall, flows from the first sidewall to the second sidewall, and exits the flow guiding device along the arc-shaped structure.

[0005] One embodiment of this specification provides a crystal growth apparatus. The crystal growth apparatus includes: a flow guiding device; a crucible for holding the raw material liquid; and a tray for supporting a seed crystal, on which the crystal is grown. During the crystal growth process, the growth surface of the seed crystal is in contact with the raw material liquid. The flow guiding device is located below the growth surface, and the growth surface faces the first space of the flow guiding device. The direction from the first sidewall to the second sidewall is opposite to the step flow direction of the growth surface.

[0006] One embodiment of this specification provides a crystal growth method. The crystal growth method includes: growing the crystal using a crystal growth apparatus; the crystal growth method includes: a raw material preparation process, including: adding raw materials for growing the crystal to the crucible; heating the raw materials to obtain the raw material liquid; and a growth process, including: moving the tray so that the growth surface of the seed crystal contacts the raw material liquid, and growing the crystal on the growth surface of the seed crystal; adjusting the position of the flow guiding device so that the flow guiding device is located below the growth surface, the growth surface is located in the first space of the flow guiding device, and the direction from the first sidewall to the second sidewall is opposite to the step flow direction of the growth surface. Attached Figure Description

[0007] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0008] Figure 1 This is a cross-sectional schematic diagram of a flow guiding device according to some embodiments of this specification.

[0009] Figure 2 This is a three-dimensional structural schematic diagram of the flow guiding device shown in some embodiments of this specification.

[0010] Figure 3 yes Figure 2 A sectional view.

[0011] Figure 4 This is a schematic diagram of the structure of a crystal growth apparatus according to some embodiments of this specification.

[0012] Figure 5 This is a schematic diagram of the tray structure according to some embodiments of this specification.

[0013] Figure 6 This is a schematic diagram showing the relative positions of the seed crystal and the flow guiding device according to some embodiments of this specification.

[0014] Figure 7This is a schematic diagram of the structure of a stirring device according to some embodiments of this specification.

[0015] Explanation of reference numerals in the attached drawings: 10 is a crystal growth apparatus; 100 is a flow guiding device; 110 is a flow guiding sidewall; 111 is a first sidewall; 1111 is a first inner wall; 1112 is a second inner wall; 112 is a second sidewall; 1121 is an arc-shaped structure; 120 is a partition plate; 121 is an opening; 130 is a first space; 140 is a second space; 150 is a baffle; 151 is a guiding platform; 152 is a guiding slope; 160 is an inlet; 200 is a crucible; 300 is a raw material liquid; 400 is a tray; 410 is a seed crystal rod; 420 is a seed crystal holder; 500 is a seed crystal; 510 is a growth surface; 520 is a connecting surface; 600 is a stirring device; 610 is a connecting sleeve; 620 is a connecting frame; 630 is a connecting rod; 640 is a stirring paddle; 700 is a support rod; 800 is a flow guiding plate. Detailed Implementation

[0016] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0017] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0018] Figure 1 This is a cross-sectional schematic diagram of a flow guiding device according to some embodiments of this specification. Figure 2 This is a three-dimensional structural schematic diagram of the flow guiding device shown in some embodiments of this specification. Figure 3 yes Figure 2 A sectional view. For example... Figure 1 , Figure 2 , Figure 3 As shown, the flow guiding device 100 is used to adjust the flow direction of the raw material liquid during the crystal growth process, and includes a flow guiding sidewall 110 and a partition plate 120.

[0019] The flow-guiding sidewall 110 can surround a flow-guiding space that guides the flow of the feed liquid. In some embodiments, the flow-guiding sidewall 110 can surround a first direction (e.g., Figure 1 The flow guide space is formed in the Z direction shown. The projection of the flow guide sidewall 110 around the formed flow guide space along the first direction can be of various shapes. For example, the projection can be circular, elliptical, rectangular or other shapes.

[0020] A partition plate 120 is disposed within the flow guiding space. The partition plate 120 is capable of dividing the flow guiding space into multiple regions. In some embodiments, the partition plate 120 can divide the flow guiding space into a first space 130 and a second space 140 along a first direction. In some embodiments, the partition plate 120 can be connected to the inner wall of the flow guiding sidewall 110 in various ways. For example, the connection between the partition plate 120 and the inner wall of the flow guiding sidewall 110 can be a detachable connection or a non-detachable connection. Exemplary detachable connections include at least one of threaded connections, adhesives, snap-fit ​​connections, etc. Exemplary non-detachable connections include at least one of welding, integral molding, etc.

[0021] The flow-guiding sidewall 110 may include a first sidewall 111 and a second sidewall 112. The first sidewall 111 and the second sidewall 112 may be two opposing sidewalls within the flow-guiding sidewall 110. In some embodiments, the first sidewall 111 and the second sidewall 112 may be two opposing sidewalls along a direction in a plane perpendicular to the first direction. For example, as... Figure 1 As shown, the first sidewall 111 and the second sidewall 112 are opposite each other along the X direction.

[0022] In some embodiments, the inner wall of the first sidewall 111 protrudes outward toward the flow guide space. In some embodiments, the inner wall of the first sidewall 111 includes a first inner wall 1111 and a second inner wall 1112. The first inner wall 1111 is located within the first space 130, and the second inner wall 1112 is located within the second space 140. In some embodiments, the first inner wall 1111 may be a plane or an arc surface, and / or the second inner wall 1112 may also be a plane or an arc surface. In some embodiments, the first inner wall 1111 and the second inner wall 1112 may be directly connected or connected by a sharp corner or a rounded arc. The transition connection portion protrudes outward toward the flow guide space. For example, as shown in... Figure 1-3 As shown, the first inner wall 1111 and the second inner wall 1112 can form a V-shaped structure, with the tip of the V-shaped structure facing away from the partition plate 120. In some embodiments, the tip of the V-shaped structure can be flush with the partition plate 120.

[0023] The first sidewall 111 can change the flow direction of the raw material liquid, allowing it to enter the first space 130 from the second space 140 through the opening 121. The first inner wall 1111 and the second inner wall 1112 have an angle, forming a protrusion towards the outside of the guiding space, so that the raw material liquid enters the opening 121 from the second space 140 along the second inner wall 1112, changes its flow direction under the action of the first inner wall 1111, and flows into the first space 130.

[0024] In some embodiments, the inner wall of the second sidewall 112 may be an arcuate structure 1121. The partition 120 may include a first end and a second end (not shown). For example, along the X direction, the partition 120 may include a first end and a second end. The first end of the partition 120 may be the end of the partition 120 near the second sidewall 112, and the second end of the partition 120 may be the end of the partition 120 near the first sidewall 111. In some embodiments, the first end of the partition 120 is transitionally connected to the first end of the arcuate structure 1121. The first end of the arcuate structure 1121 may be the end of the arcuate structure 1121 near the partition 120. The arcuate structure 1121 is located in the first space 130, and the second end of the arcuate structure 1121 extends away from the first sidewall 111. The second end of the arcuate structure 1121 may be the end of the arcuate structure 1121 near the second sidewall 112.

[0025] In some embodiments, an opening 121 may be formed between the second end of the partition plate 120 and the inner wall of the first sidewall 111. The raw material liquid can flow from the second space 140 along the second inner wall 1112 through the opening 121, then along the first inner wall 1111 into the first space 130, flowing from the first sidewall 111 to the second sidewall 112 on the partition plate 120, and exiting the guide device 100 along the arc-shaped structure 1121. The arc-shaped structure 1121 ensures that the raw material liquid can flow out of the guide device 100 from the first space 130 without backflow.

[0026] The first sidewall 111 acts as a guide, guiding the raw material liquid into the opening 121 via the second inner wall 1112, and then changing the flow direction of the raw material liquid through the first inner wall 1111 to enter the first space 130. If the angle between the first inner wall 1111 and the partition plate 120 is large, the space between the first inner wall 1111 and the partition plate 120 is large, the guiding effect of the first inner wall 1111 on the raw material liquid is poor, and the speed at which the raw material liquid enters the first space 130 is slow, which will affect the crystal growth efficiency. If the angle between the first inner wall 1111 and the partition plate 120 is small, the space between the first inner wall 1111 and the partition plate 120 will also be small, the first inner wall 1111 will have a greater blocking effect on the raw material liquid, and the raw material liquid will collide strongly with the partition plate 120 after entering the first space 130, thus causing disturbance within the first space 130 and affecting the crystal growth quality. In some embodiments, in order to allow the raw material liquid to enter the first space 130 as horizontally as possible (along the partition plate 120) under the action of the first inner wall 1111, the angle between the first inner wall 1111 and the partition plate 120 is 40°-45°.

[0027] If the angle between the second inner wall 1112 and the partition plate 120 is large, the guiding effect of the second inner wall 1112 on the raw material liquid will be poor, and there will be a problem that the raw material liquid cannot be guided into the opening 121. If the angle between the second inner wall 1112 and the partition plate 120 is small, the amount of raw material liquid entering the opening 121 per unit time will be reduced, thereby reducing the crystal growth efficiency. In some embodiments, the angle between the second inner wall 1112 and the partition plate 120 is 40°-60°.

[0028] The size of the opening 121 can be the distance between the second end of the partition plate 120 and the inner wall of the first sidewall 111, for example, the distance along the X direction. If the opening 121 is too large, it will cause the raw material liquid entering the first space 130 to become dispersed, reducing the flow rate of the raw material liquid in the first space 130, thereby reducing the crystal growth efficiency. If the opening 121 is too small, it will increase the resistance when the raw material liquid enters the first space 130, and it cannot be guaranteed that the raw material liquid can flow smoothly through the opening 121. In some embodiments, the size of the opening 121 is 2-5 mm.

[0029] By using a flow guiding device, the flow direction of the raw material liquid in the first space 130 can be controlled so that the angle between the flow direction of the raw material liquid in the first space 130 and the step flow direction of the seed crystal is greater than 90° and less than or equal to 180°, which can make the surface of the grown crystal smooth during the crystal growth process.

[0030] In some embodiments, such as Figure 1 , Figure 3 As shown, at least one baffle 150 is provided in the second space 140. The baffle 150 is connected to the flow guide sidewall 110.

[0031] The baffle 150 can guide the flow of the raw material liquid, making it easier for the raw material liquid to flow into the opening 121, and allowing it to flow into the opening 121 in a concentrated energy state, thereby ensuring the flow rate and velocity of the raw material liquid in the guiding device 100, and ensuring the growth rate and growth quality of the crystal.

[0032] In some embodiments, the baffle 150 forms at least one inlet 160 in the second space 140. The raw material liquid can enter the second space 140 through the inlet 160, and the raw material liquid entering the second space 140 can flow along the baffle 150 to the opening 121. In some embodiments, the inlet 160 can have various shapes. For example, the inlet 160 can be one or more of a circular through-hole, a square through-hole, an elongated through-hole, a pipe, and a channel. In some embodiments, the baffle 150 can be located at the bottom of the second space 140 (e.g., at the bottom of the opening 121). Figure 1 and Figure 3At least one inlet 160 is formed on the side of the baffle 150 (as shown). The baffle 150 may form an inlet 160 with the flow-guiding sidewall 110 (e.g., the first sidewall 111 and / or the second sidewall 112), and / or an inlet 160 may also be formed between two adjacent baffles 150. The size of the inlet 160 can be the distance between the baffle 150 and the flow-guiding sidewall 110 (e.g., the first sidewall 111 and / or the second sidewall 112), and / or the distance between two adjacent baffles 150. If the inlet 160 is large, it will disperse the feed liquid entering the second space 140, reducing the flow rate of the feed liquid in the first space 130, thereby reducing the crystal growth efficiency. If the inlet 160 is small, it will increase the resistance when the feed liquid enters the second space 140, making it impossible to guarantee that the feed liquid can flow smoothly into the second space 140, thus reducing the flow rate of the feed liquid entering the flow guiding device 100.

[0033] In some embodiments, such as Figure 1 , Figure 3 As shown, the baffle 150 may include a guide ramp 152 and a guide platform 151.

[0034] The guide ramp 152 can be used to control the flow direction of the feed liquid when it enters the second space 140. The first end of the guide ramp 152, away from the partition plate 120, forms at least one inlet 160 at the bottom of the second space 140. In some embodiments, a channel-type inlet 160 can be formed between two adjacent guide ramps 152 and / or between the guide ramp 152 and the flow-guiding sidewall 110 (e.g., the first sidewall 111 and / or the second sidewall 112). The distance between two adjacent guide ramps 152 and / or the distance between the guide ramp 152 and the flow-guiding sidewall 110 (e.g., the first sidewall 111 and / or the second sidewall 112) is the size of the inlet 160. The second end of the guide ramp 152 near the partition plate 120 slopes towards the opening 121. In some embodiments, the guide ramp 152 can be parallel to the second inner wall 1112 of the first sidewall 111.

[0035] A guide channel (not shown) is formed between the guide platform 151 and the partition plate 120. The raw material liquid enters the second space 140 from the inlet 160, flows along the guide slope through the guide channel, and flows into the opening 121. The end of the guide platform 151 away from the opening 121 is connected to the second end of the guide slope 152. In some embodiments, a gap is left between the guide platforms 151 of two adjacent baffles 150, and / or, a gap is left between the guide platform 151 near the first sidewall 111 or the second sidewall 112 and the first sidewall 111 or the second sidewall 112, the gap allowing the raw material liquid to enter the guide channel from the inlet 160. In some embodiments, each gap is along a second direction (e.g., Figure 1The widths (in the X direction shown) may be the same or different. In some embodiments, the number of guide platforms 151 is the same as the number of guide ramps 152 and they are connected in a one-to-one correspondence.

[0036] By using a guide slope, the direction of the raw material liquid entering the second space can be controlled, and by using a guide platform, the direction of the raw material liquid's flow within the second space can be controlled. This prevents turbulence and unnecessary disturbances caused by the raw material liquid within the second space, thus avoiding adverse effects on crystal growth. Furthermore, the guide slope and guide platform act as a conduit for the raw material liquid, allowing it to flow more easily into the opening 121 and in a concentrated energy state. This ensures the flow rate and velocity of the raw material liquid within the guiding device 100, thereby guaranteeing the crystal growth rate and quality.

[0037] Figure 4 This is a schematic diagram of the crystal growth apparatus shown in some embodiments of this specification. For example... Figure 4 As shown, the crystal growth apparatus 10 includes a flow guiding device 100, a crucible 200, and a tray 400. The flow guiding device 100 and the tray 400 can be disposed within the crucible 200. The flow guiding device 100 is located below the tray 400. For more information about the flow guiding device 100, please refer to the relevant description above in this specification.

[0038] The crucible 200 is used to hold the raw material liquid 300. A heating device can be provided on the outside of the crucible 200 for heating the raw material liquid. In some embodiments, the top of the crucible 200 is open. The flow guide device 100 and the tray 400 can be inserted into the crucible 200 from the top opening.

[0039] The tray 400 can be used to support the seed crystal 500, allowing the seed crystal 500 to be placed inside the crucible 200, where crystals can grow on the growth surface of the seed crystal 500. The growth surface of the seed crystal 500 can be the side of the seed crystal 500 facing the raw material liquid 300.

[0040] Figure 5 This is a schematic diagram of the tray structure according to some embodiments of this specification. For example... Figure 5 As shown, the tray 400 includes a seed crystal holder 420 and a seed crystal rod 410. The seed crystal rod 410 is disposed on the side of the seed crystal holder 420 away from the raw material liquid. The seed crystal 500 is disposed on the side of the seed crystal holder 420 facing the raw material liquid. In some embodiments, the seed crystal 500 may be adhered to the seed crystal holder 420.

[0041] Figure 6 This is a schematic diagram showing the relative positions of the seed crystal and the current guiding device according to some embodiments of this specification. For example... Figure 6As shown, the seed crystal 500 may include a growth surface 510 and a connecting surface 520. The connecting surface 520 can be connected to the seed crystal holder 420. The growth surface 510 can be used to grow crystals. During crystal growth, the growth surface 510 of the seed crystal 500 is in contact with the raw material liquid 300. A stepped surface is provided on the growth surface 510, and the step flow direction of the stepped surface is opposite to the second direction. Step flow refers to a crystal growth mode in which gas phase molecules adsorbed on the adjacent crystal surfaces of the platform-step structure are incorporated into the crystal lattice at the steps, causing each step to flow forward in parallel. The step flow direction refers to the direction in which the steps flow parallel to each other.

[0042] In some embodiments, the flow guiding device 100 is located below the growth surface 510, which is located within the first space 130. In some embodiments, the connecting surface 520 is located above the liquid surface of the raw material liquid 300. The raw material liquid 300 entering the first space 130 flows from the first sidewall 111 to the second sidewall 112, and then flows out of the flow guiding device 100 through the arc-shaped structure 1121. In the crystal growth apparatus 10, the flow direction of the raw material liquid 300 within the first space 130 (from the first sidewall 111 to the second sidewall 112) is opposite to the step flow direction of the growth surface of the seed crystal 500 (for example, the angle between the flow direction of the raw material liquid 300 within the first space 130 and the step flow direction of the growth surface of the seed crystal 500 is greater than 90° and less than or equal to 180°), thereby enabling the grown crystal surface to be smooth. In some embodiments, the seed crystal 500 may be parallel to the separator plate 120.

[0043] In some embodiments, a support rod 700 may be provided within the crucible 200. The support rod 700 can be used to support the flow guiding device 100. In some embodiments, the support rod 700 may be connected to the partition plate 120 and / or the baffle 150 (e.g., the guide ramp 152 and / or the guide platform 151). The connection method may include detachable connection, non-detachable connection, etc. Exemplary detachable connections include one or more of the following methods: threaded connection, snap-fit, shaft and hole fit, etc. Exemplary non-detachable connections include welding, integral molding, etc. In some embodiments, the connection point between the support rod 700 and the guide platform 151 may be located at or near the center of gravity of the flow guiding device 100, which is beneficial to improving the stability of the flow guiding device 100. In some embodiments, multiple connection points may be included between the support rod 700 and the guide platform 151. For example, three connection points may be provided between the support rod 700 and the guide platform 151 to improve the stability of the flow guiding device 100. The length of the support rod 700 can be adjusted to adjust the height of the flow guiding device 100 in the crucible.

[0044] In some embodiments, during crystal growth, the raw material liquid 300 in the crucible 200 flows relative to the flow guiding device 100, while the seed crystal 500 remains relatively stationary with respect to the flow guiding device 100. When the raw material liquid 300 flows relative to the flow guiding device 100, a portion of the raw material liquid 300 enters the second space 140, passes through the opening 121, flows along the inner wall of the first sidewall 111 into the first space 130, flows through the first sidewall 111, passes through the growth surface 510 of the seed crystal 500, then flows to the second sidewall 112, and exits the flow guiding device along the arc-shaped structure.

[0045] In some embodiments, such as Figure 6 As shown, the isolation plate 120 and the growth surface 510 of the seed crystal 500 are at a distance L in the first direction.

[0046] The flow rate of the feed solution 300 through the growth surface 510 has an impact on crystal growth (e.g., affecting crystal growth rate, growth stability, and growth quality). During the flow of the feed solution 300, mass transfer occurs between it and the crystal. The faster the feed solution 300 flows, the faster the crystal growth rate. However, excessively fast crystal growth can lead to polycrystalline growth, thereby deteriorating crystal growth stability and growth quality.

[0047] After the raw material liquid 300 enters the first space 130, it carries a certain amount of energy (e.g., the remaining kinetic energy of the raw material liquid 300 after entering the first space 130). When the distance L is too small, the raw material liquid 300 will collide strongly with the seed crystal 500, causing the raw material liquid 300 to flow smoothly through the growth surface 510, resulting in poor crystal quality. When the distance L is too large, the energy of the raw material liquid 300 will be dispersed, and the speed at which the raw material liquid 300 flows through the growth surface 510 will decrease, resulting in a decrease in crystal growth efficiency. In some embodiments, in order to ensure crystal growth quality and growth efficiency, L ranges from 0.5 to 3 mm.

[0048] In some embodiments, the relative positions of the seed crystal 500 and the separator 120 can be changed. For example, during crystal growth, the seed crystal 500 becomes increasingly thick, causing the distance L to decrease. Therefore, during crystal growth, the seed crystal 500 can be moved upward and / or the flow guide device 100 can be moved downward to keep the distance L within a certain range (e.g., 0.5-3 mm). In some embodiments, the seed crystal 500 can be moved upward synchronously by lifting the tray 400. In some embodiments, the flow guide device 100 can be moved downward by reducing the length of the support rod.

[0049] In some embodiments, such as Figure 4As shown, at least a portion of the first space 130 of the flow guiding device 100 is higher than the surface of the raw material liquid 300. This prevents the raw material liquid 300 from crossing the flow guiding sidewall 110 and entering the first space 130, and prevents the raw material liquid 300 within the first space 130 from becoming disturbed and changing its flow direction. During stirring, the raw material liquid may experience eddies or even chaotic flow patterns, causing some of the raw material liquid to enter the flow guiding device from the first space, disrupting the unidirectional flow of the raw material liquid in the first space. Therefore, the upper edge of the flow guiding sidewall is higher than the surface of the raw material liquid to prevent backflow. At the same time, the height of the first space must not be too high, otherwise the raw material liquid flowing on the partition plate will not be able to overcome the arc structure, leading to backflow and disrupting the unidirectional flow of the raw material liquid in the first space. In some embodiments, the upper edge of the flow guiding sidewall is 2-5 mm higher than the surface of the raw material liquid.

[0050] In some embodiments, such as Figure 4 As shown, at least a portion of the second space 140 of the flow guiding device 100 is located in the raw material liquid 300. In some embodiments, the inlet 160 is lower than the liquid surface of the raw material liquid 300 to ensure that the raw material liquid 300 smoothly enters the flow guiding device 100.

[0051] The crystal growth apparatus 10 may further include a stirring device 600. The stirring device 600 is used to stir the raw material liquid 300, causing it to flow within the crucible 200. During the flow of the raw material liquid 300, a portion of it may enter the guiding device 100 through the inlet 160. At least a portion of the stirring device 600 may be positioned between the guiding device 100 and the inner wall of the crucible 200 to prevent interference or collision between the stirring device 600 and the guiding device 100 or the crucible 200 during the stirring of the raw material liquid 300.

[0052] If the stirring speed is too fast, the raw material liquid 300 is prone to violent disturbance, which will affect the stability of the flow guiding device 100. Furthermore, the raw material liquid 300 will splash up and enter the flow guiding device 100 above the flow guiding sidewall 110, disrupting the unidirectional flow of the raw material liquid 300 within the first space 130 and affecting the crystal growth quality. If the stirring speed is too slow, the raw material liquid 300 lacks momentum, resulting in a slower flow rate into the flow guiding device 100, which will reduce crystal growth efficiency. In some embodiments, the stirring speed is 20–50 revolutions per minute.

[0053] Figure 7 This is a schematic diagram of the stirring device shown in some embodiments of this specification. For example... Figure 7 As shown, the stirring device 600 includes a stirring paddle 640.

[0054] The stirring paddle 640 has a certain contact area with the raw material liquid 300. The stirring device 600 can drive the stirring paddle 640 to rotate, and the stirring paddle 640 can agitate the raw material liquid 300, causing it to rotate. In some embodiments, the stirring paddle 640 can be a flat plate structure or an arc-shaped structure. In some embodiments, the stirring paddle 640 can be perpendicular to the rotation direction, or it can be inclined relative to the rotation direction. In some embodiments, the stirring paddle 640 can be located below the flow guiding device 100. In some embodiments, the rotation center of the stirring paddle 640 can coincide with the axis of the support rod 700. In some embodiments, at least one stirring paddle 640 can be provided. When two stirring paddles 640 are provided, they can be symmetrically distributed with the axis of the support rod 700 as the axis of symmetry. When at least three stirring paddles 640 are provided, they can be arranged in a ring with the axis of the support rod 700 as the axis.

[0055] The impeller 640 and the flow guiding device 100 are separated by a distance H in the first direction. The distance H between the impeller 640 and the flow guiding device 100 in the first direction refers to the distance between a certain position of the impeller 640 and the bottom of the flow guiding device 100 in the first direction; for example, the top of the impeller 640 (e.g., the top of the impeller 640). Figure 4 The distance H between the agitator 640 (as shown) and the bottom of the flow guiding device 100 in the first direction is 5-20 mm. When H is small, the agitator 640 is closer to the surface of the raw material liquid 300. When the agitator 640 agitates the raw material liquid 300, the surface of the raw material liquid 300 may fluctuate significantly, causing some raw material liquid to enter the first space 130 from the upper surface of the flow guiding device 100, thus affecting the flow of the raw material liquid 300 in the first space 130 and consequently affecting the crystal growth quality. When H is large, the agitator 640 is farther from the flow guiding device 100. When the agitator 640 agitates the raw material liquid 300, the flow effect of the raw material liquid 300 near the lower part of the flow guiding device 100 is weaker, which may reduce the speed or effect of the raw material liquid 300 entering the flow guiding device 100. This affects the flow efficiency of the raw material liquid 300 in the flow guiding device 100 and the crystal growth efficiency. In some embodiments, the distance H between the agitator 640 and the flow guiding device 100 in the first direction is 5-20 mm. In some embodiments, the distance H between the stirring paddle 640 and the flow guiding device 100 in the first direction can be adjusted. The adjustment can be performed in various ways; for example, the entire stirring device 600 can be raised and lowered in the first direction. Alternatively, the stirring paddle 640 can be raised and lowered in the first direction.

[0056] In some embodiments, the agitator 640 can be provided in multiple layers, with at least one agitator 640 in each layer. The rotational speed of the agitator 640 closer to the flow guiding device 100 can be greater than that of the agitator 640 farther from the flow guiding device 100. By using multiple layers of agitator 640 to agitate the raw material liquid 300, the power of the raw material liquid 300 can be increased, and the raw material distribution inside the raw material liquid 300 can be made more uniform.

[0057] In some embodiments, the height of the agitator 640 along the first direction can be 1 / 3 to 1 / 2 of the height of the raw material liquid 300. The width of the agitator 640 along the second direction can be 1 / 3 to 1 / 2 of the height of the agitator 640.

[0058] In some embodiments, the angle and / or position of the rotation center of the agitator 640 can be adjusted.

[0059] In some embodiments, the stirring device 600 may further include a connecting sleeve 610, a connecting frame 620, and a connecting rod 630. The connecting frame 620 is connected to the connecting sleeve 610, one end of the connecting rod 630 is connected to the connecting frame 620, and the other end of the connecting rod 630 is connected to the stirring paddle 640.

[0060] The connecting sleeve 610 can be fitted onto the outside of the seed crystal rod 410. The connecting sleeve 610 can be connected to a drive structure, which drives the connecting sleeve 610 to rotate. In some embodiments, the drive structure may include various structures, such as a gear drive chain, a belt drive chain, a chain drive chain, or a worm gear drive chain. In some embodiments, the connecting sleeve 610 and the seed crystal rod 410 are spaced apart. In some embodiments, the connecting sleeve 610 and the seed crystal rod 410 can be rolled together. In some embodiments, at least one bearing can be connected between the connecting sleeve 610 and the seed crystal rod 410.

[0061] The connecting frame 620 can serve as a mounting base for connecting the connecting rod 630. When the connecting sleeve 610 rotates, it can drive the connecting frame 620 to rotate synchronously. In some embodiments, the connecting frame 620 can be a ring structure.

[0062] The connecting rod 630 can be connected to the stirring paddle 640, and when the connecting sleeve 610 rotates, it drives the stirring paddle 640 to rotate synchronously. In some embodiments, the connecting rod 630 can be disposed between the flow guiding device 100 and the inner wall of the crucible 200 to avoid collision or interference between the connecting rod 630 and the flow guiding device 100 or the crucible 200. In some embodiments, the connecting rod 630 can be a bent rod-shaped mechanism. The connecting rod 630 and the stirring paddle 640 are arranged in a one-to-one correspondence.

[0063] In some embodiments, the connecting rod 630 is a telescopic structure.

[0064] In some embodiments, such as Figure 4 As shown, the crystal growth apparatus 10 also includes a flow guide plate 800. The flow guide plate 800 is located between the second sidewall 112 of the flow guide device 100 and the crucible 200. The first end of the flow guide plate 800 near the crucible 200 is connected to the inner wall of the crucible 200, and the second end of the flow guide plate 800 away from the crucible 200 is lower than the first end of the flow guide plate 800.

[0065] After the raw material liquid 300 in the first space 130 of the flow guiding device 100 leaves the flow guiding device 100 through the arc structure 1121, it falls into the crucible 200 and collides with the raw material liquid 300 in the crucible 200, causing disturbance and even splashing some of the raw material liquid 300. When the raw material liquid 300 is stirred, internal disturbance also exists, leading to instability in the liquid surface. The flow guide plate 800 can limit the liquid surface of the raw material liquid 300, reducing fluctuations or disturbances and preventing the raw material liquid 300 from crossing the flow guiding sidewall 110 and entering the flow guiding device 100. In some embodiments, the second end of the flow guide plate 800 is located below the liquid surface of the raw material liquid 300. In some embodiments, the first end of the flow guide plate 800 can be higher than, flush with, or lower than the liquid surface of the raw material liquid 300. In some embodiments, the first end of the guide plate 800 may be higher than or flush with the second end of the arc-shaped structure 1121. In some embodiments, the angle between the guide plate 800 and the inner wall of the crucible 200 may be 30°-60°. In some embodiments, the guide plate 800 may be arranged in a ring on the inner wall of the crucible 200.

[0066] A crystal growth method includes growing a crystal using a crystal growth apparatus 10. Further details regarding the crystal growth apparatus 10 can be found in the preceding description of this specification. Crystal growth methods include melt growth, solution growth, vapor phase growth, and solid phase growth, among others.

[0067] In some embodiments, when growing crystals using a solution growth method, the crystal growth method includes the following steps:

[0068] Step 1, the preparation process of the raw material solution, includes:

[0069] Add the raw materials used for crystal growth to crucible 200;

[0070] The raw materials are heated to obtain raw material liquid 300, which includes silicon and carbon elements. This application does not limit the preparation method of the raw material liquid.

[0071] Step 2, the growth process, including:

[0072] The tray 400 is moved downwards so that the growth surface 510 of the seed crystal 500 comes into contact with the raw material liquid 300. This allows crystals to grow on the growth surface 510 of the seed crystal 500.

[0073] The position of the flow guiding device 100 is adjusted so that it is located below the growth surface 510, which is situated within the first space 130 of the flow guiding device 100. The direction from the first sidewall 111 to the second sidewall 112 is opposite to the step flow direction of the growth surface 510. Once the raw material liquid 300 flows relative to the flow guiding device 100 and can flow within the first space 130, crystal growth can begin on the growth surface 510.

[0074] In some embodiments, while keeping the seed crystal stationary during crystal growth, the raw material liquid 300 is stirred using a stirring paddle 640. The stirring paddle 640 drives the raw material liquid 300 to flow entirely within the crucible 200, causing relative flow between the raw material liquid 300 and the flow guiding device 100. This provides power to the raw material liquid 300, enabling it to flow within the flow guiding device 100. Appropriate settings of parameters related to the stirring device (e.g., stirring speed, number and distribution of stirring paddles, structure of the stirring device, relative position of the stirring device and the flow guiding device, relative position of the stirring device and the raw material liquid, etc.) help ensure that the solute-laden liquid stream provides sufficient solute concentration for single crystal growth when passing over the growth surface, without compromising the stability of the crystal growth process.

[0075] The growth process may also include a first growth stage. In the first growth stage, the solute concentration in the raw material solution 300 is relatively high. While maintaining crystal growth efficiency, the flow rate of the raw material solution 300 within the first space 130 can be reduced. At a constant rotation speed, the farther the stirring paddle 640 is from the flow guiding device 100, the weaker the stirring effect of the stirring paddle 640 on the raw material solution 300 near the flow guiding device 100, resulting in a lower velocity of the raw material solution 300 near the flow guiding device 100 and a lower velocity of the raw material solution 300 flowing within the first space 130. By increasing the distance between the stirring paddle 640 and the flow guiding device 100, the flow rate of the raw material solution 300 within the first space can be reduced. In the first growth stage, the stirring device 600 can be adjusted to a first position, at which point the stirring paddle 640 is located below the flow guiding device 100. In some embodiments, the first distance can be greater than half the distance between the bottom of the flow guiding device 100 and the inner bottom surface of the crucible 200, allowing the stirring paddle 640 to approach the bottom region of the crucible 200. This reduces the flow rate of the raw material liquid 300 in the first space.

[0076] The growth process may also include a second growth stage. In the second growth stage, the solute in the raw material solution 300 is consumed over a period of time, and the solute concentration decreases. While maintaining the crystal growth efficiency, the flow rate of the raw material solution 300 within the first space 130 can be increased. In the second growth stage, the stirring device 600 is adjusted to a second position. In this second position, the stirring paddle 640 of the stirring device 600 is located below the flow guiding device 100. The distance between the stirring paddle 640 and the flow guiding device 100 in the first direction is a second distance, where the first distance is greater than the second distance. In some embodiments, the second distance may be less than half the distance between the bottom of the flow guiding device 100 and the inner bottom surface of the crucible 200. This allows the stirring paddle 640 to approach the bottom region of the flow guiding device 100, thereby increasing the flow rate of the raw material solution 300 within the first space.

[0077] During the growth process, a crystal grows on the seed crystal 500, and the thickness of the crystal gradually increases as the growth process progresses. The growth process may also include adjusting the distance between the isolation plate 120 and the growth surface 510 in the first direction. In some embodiments, the flow guiding device 100 is supported by the support rod 700, and the height of the flow guiding device 100 does not change, but the height of the growth surface 510 can be increased along the first direction. For example, a lifting device is used to connect to the tray 400, and during the crystal growth process, the height of the tray 400 is gradually increased using the lifting device, thereby gradually increasing the height of the growth surface 510. In some embodiments, the support rod 700 may be a retractable structure, and the support rod 700 may be shortened in the opposite direction of the first direction, thereby causing the flow guiding device 100 to descend and increasing the distance between the isolation plate 120 and the growth surface 510 in the first direction. In some embodiments, the distance between the isolation plate 120 and the growth surface 510 in the first direction can be adjusted by simultaneously raising the height of the seed crystal 500 and lowering the height of the flow guiding device 100.

[0078] During growth, the step flow direction on the growth surface 510 must be kept opposite to the direction of the raw material liquid 300 flowing from the first sidewall 111 to the second sidewall 112. During growth, the seed crystal 500 must be kept stationary to prevent changes in the step flow direction, thereby ensuring the crystal growth quality and efficiency.

[0079] The specification describes the flow guiding device, crystal growth method, and crystal growth apparatus using solution-based silicon carbide crystal growth as an example. It can be understood that the flow guiding device, crystal growth method, and crystal growth apparatus of this application can also be applied to other application scenarios, such as any scenario where liquid-phase crystal growth requires a specific flow direction.

[0080] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0081] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0082] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A flow guiding device for adjusting the flow direction of the raw material solution during crystal growth, characterized in that, include: A flow-guiding sidewall, wherein the flow-guiding sidewall forms a flow-guiding space around a first direction; An isolation plate is disposed in the flow guiding space, dividing the flow guiding space into a first space and a second space along the first direction, wherein the first direction is perpendicular to the isolation plate, and the first space is located above the second space; The flow-guiding sidewall includes a first sidewall and a second sidewall, wherein... The inner wall of the first sidewall includes a first inner wall and a second inner wall. The first inner wall is located in the first space, and the second inner wall is located in the second space. There is an angle between the first inner wall and the second inner wall, forming a protrusion towards the outside of the flow guiding space. The angle between the first inner wall and the isolation plate is 40°-45°, and the angle between the second inner wall and the isolation plate is 40°-60°. The inner wall of the second sidewall is an arc-shaped structure, which is located in the first space. The first end of the isolation plate is transitionally connected to the first end of the arc-shaped structure, and the second end of the arc-shaped structure extends away from the first sidewall. The second end of the isolation plate opposite to the first end forms an opening with the inner wall of the first sidewall. At least one baffle is provided in the second space; The at least one baffle is connected to the flow guide sidewall; The at least one baffle forms at least one inlet in the second space for allowing the raw material liquid to enter the opening from the at least one inlet along the at least one baffle; The raw material liquid enters the opening from the second space along the second inner wall, changes its flow direction under the action of the first inner wall, flows into the first space, flows from the first side wall to the second side wall, and flows out of the guiding device along the arc-shaped structure.

2. The flow guiding device as described in claim 1, characterized in that, The baffle includes a guide ramp and a guide platform. The first end of the guide ramp away from the isolation plate forms at least one entrance at the bottom of the second space. The second end of the guide ramp near the isolation plate is inclined toward the opening. The end of the guide platform away from the opening is connected to the second end of the guide ramp. A guide channel is formed between the guide platform and the isolation plate.

3. A crystal growth apparatus, characterized in that, include: The flow guiding device according to claim 1 or 2; A crucible for holding the raw material liquid; A tray for supporting a seed crystal, on which the crystal grows on the growth surface of the seed crystal; During the crystal growth process, the growth surface of the seed crystal is in contact with the raw material liquid, the flow guiding device is located below the growth surface, the growth surface faces the first space of the flow guiding device, and the angle between the direction from the first sidewall to the second sidewall and the step flow direction of the growth surface is greater than 90° and less than or equal to 180°.

4. The crystal growth apparatus as described in claim 3, characterized in that, The distance between the isolation plate and the growth surface of the seed crystal in the first direction is 0.5-3 mm.

5. The crystal growth apparatus as described in claim 3, characterized in that, At least a portion of the first space of the flow guiding device is above the liquid level of the raw material liquid.

6. The crystal growth apparatus as described in claim 3, characterized in that, At least a portion of the second space of the flow guiding device is located in the raw material liquid.

7. The crystal growth apparatus as described in claim 3, characterized in that, The crystal growth apparatus further includes a stirring device for stirring the raw material liquid.

8. The crystal growth apparatus as described in claim 7, characterized in that, The stirring device includes a stirring paddle; The stirring paddle is located below the flow guiding device, and the distance between the stirring paddle and the flow guiding device in the first direction is 5-20mm.

9. The crystal growth apparatus as described in claim 3, characterized in that, The crystal growth apparatus further includes a flow guide plate; The guide plate is located between the second side wall of the guide device and the crucible; The first end of the guide plate is connected to the inner wall of the crucible, and the second end of the guide plate is lower than the first end of the guide plate.

10. A crystal growth method, characterized in that, include: The crystal is grown using the crystal growth apparatus of claim 3, wherein the crystal growth method comprises: The raw material preparation process includes: The raw materials used to grow the crystal are added to the crucible; The raw material is heated to obtain the raw material liquid; The growth process includes: The tray is moved so that the growth surface of the seed crystal comes into contact with the raw material liquid, and the crystal is grown on the growth surface of the seed crystal. Adjust the position of the flow guiding device so that the flow guiding device is located below the growth surface, the growth surface is located in the first space of the flow guiding device, and the angle between the direction from the first sidewall to the second sidewall and the step flow direction of the growth surface is greater than 90° and less than or equal to 180°.

11. The crystal growth method as described in claim 10, characterized in that, The growth process further includes: stirring the raw material liquid using a stirring device.

12. The crystal growth method as described in claim 11, characterized in that, The growth process further includes: In the first growth stage, the stirring device is adjusted to a first position. In the first position, the stirring paddle of the stirring device is located below the flow guiding device, and the distance between the stirring paddle and the flow guiding device in the first direction is a first distance.

13. The crystal growth method as described in claim 12, characterized in that, The growth process further includes: In the second growth stage, the stirring device is adjusted to a second position. In the second position, the stirring paddle of the stirring device is located below the flow guiding device. The distance between the stirring paddle of the stirring device and the flow guiding device in the first direction is a second distance. The first distance is greater than the second distance. The second growth stage is after the first growth stage.

14. The crystal growth method as described in claim 10, characterized in that, The growth process further includes: Adjust the distance between the isolation plate and the growth surface in the first direction.

15. The crystal growth method as described in claim 10, characterized in that, During the growth process, the seed crystal is kept from rotating.

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