Middle barrel of silicon carbide crystal growth furnace

Abstract

The utility model discloses a middle barrel of a silicon carbide crystal growth furnace. The middle barrel comprises an inner pipe, a first flange, a second flange, an outer pipe and a wire rod, the inner pipe is in a circular pipe shape, the first flange is seamlessly connected with one end of the inner pipe, and the second flange is seamlessly connected with the other end of the inner pipe; the outer pipe is arranged on the outer side of the inner pipe in a sleeving mode, the two ends of the outer pipe are in seamless connection with the first flange and the second flange respectively, and a water inlet close to the first flange and a water outlet close to the second flange are formed in the pipe wall of the outer pipe. The wire rod is wound on the outer wall of the inner pipe, and the outer edge of the wire rod is in seamless connection with the outer pipe. According to the utility model, the heat conduction effect is improved, so that the cooling speed control precision is improved, the parallel water channel design is adopted, the temperature gradient distribution is optimized, the internal defects of the silicon carbide crystals are reduced, and the yield of the silicon carbide crystals is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon carbide crystal growth furnaces, in particular to an intermediate cylinder of a silicon carbide crystal growth furnace. Background Art

[0002] Silicon carbide is an important semiconductor material with excellent thermal conductivity, high temperature resistance and chemical stability. It is widely used in high-power electronic devices, optoelectronic devices and sensors. The working principle of the LPE (liquid phase method) silicon carbide crystal growth furnace is as follows: First, the silicon carbide substrate is placed in the furnace chamber and heated to an appropriate temperature; then, silicon carbide growth raw materials and solvents are added to the furnace chamber to form a silicon carbide solution, and the silicon carbide in the solution is gradually grown on the substrate by controlling parameters such as temperature and solution concentration; finally, the silicon carbide crystals are gradually cooled and solidified by controlling the cooling rate. Based on the above principles, in the Chinese invention patent application with application number CN202310874845.2, a device and method for multiple growth of silicon carbide crystals in a single furnace using a liquid phase method are provided.

[0003] At present, in the process of preparing silicon carbide crystals using LPE silicon carbide crystal growth furnaces, the middle cylinder of the silicon carbide crystal growth furnace is usually used to control the temperature. However, due to the defects in the structural design of the middle cylinder of the existing silicon carbide crystal growth furnace, the heat conduction effect of the middle cylinder of the existing silicon carbide crystal growth furnace is poor, resulting in low accuracy in controlling the cooling rate, and uneven temperature distribution under the same isothermal layer, which directly affects the temperature gradient and further affects the formation of silicon carbide crystals. Utility Model Content

[0004] A technical problem to be solved by the present application is that the heat conduction effect of the middle cylinder of the existing silicon carbide crystal growth furnace is poor, resulting in low precision in controlling the cooling speed.

[0005] The utility model provides an intermediate cylinder of a silicon carbide crystal growth furnace to solve the deficiencies of the prior art.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A middle cylinder of a silicon carbide crystal growth furnace comprises an inner tube, a first flange, a second flange, an outer tube and a wire rod; the inner tube is in a circular tube shape, the first flange is seamlessly connected to one end of the inner tube, and the second flange is seamlessly connected to the other end of the inner tube; the outer tube is sleeved on the outer side of the inner tube, the two ends of the outer tube are seamlessly connected to the first flange and the second flange respectively, and a water inlet adjacent to the first flange and a water outlet adjacent to the second flange are provided on the tube wall of the outer tube; the wire rod is coiled on the outer wall of the inner tube, and the outer edge of the wire rod is seamlessly connected to the outer tube.

[0008] In some embodiments, two ends of the wire rod are connected to the first flange and the second flange respectively.

[0009] In some embodiments, the outer tube is in a circular tube shape and is coaxial with the inner tube.

[0010] In some embodiments, the wire rod includes an open ring and an inclined plate. The open ring is roughly circular and has a notch. Multiple open rings are equidistantly spaced along the axial direction of the inner tube. Multiple open rings are connected end to end in sequence through the inclined plate. The head end of the open ring adjacent to the first flange is connected to the first flange through the inclined plate, and the tail end of the open ring adjacent to the second flange is connected to the second flange through the inclined plate. The inner edge of the open ring is seamlessly connected to the outer wall of the inner tube, and the outer edge of the open ring is seamlessly connected to the inner wall of the outer tube.

[0011] In some embodiments, the plane where each split ring is located is perpendicular to the axis of the inner tube.

[0012] In some embodiments, the middle cylinder of the silicon carbide crystal growth furnace further includes a water inlet pipe and a water outlet pipe, wherein the water inlet pipe is connected to the water inlet, and the water outlet pipe is connected to the water outlet.

[0013] In some embodiments, the middle cylinder of the silicon carbide crystal growth furnace also includes a first connector connected to the water inlet pipe and a second connector connected to the water outlet pipe. The outer diameter of the first connector is larger than the outer diameter of the water inlet pipe, and the outer diameter of the second connector is larger than the outer diameter of the water outlet pipe.

[0014] In some embodiments, two or four equidistantly spaced cut surfaces are disposed on the outer peripheral walls of the first connector and the second connector.

[0015] In some embodiments, a first annular groove is provided on the end surface of the first flange, a first sealing ring is provided in the first annular groove, and a second annular groove is provided on the end surface of the second flange, a second sealing ring is provided in the second annular groove.

[0016] Through the above technical solution, the intermediate cylinder of the silicon carbide crystal growth furnace provided by the utility model divides the gap between the inner tube and the outer tube into a water channel through the wire rod, so that the formed water channel has a larger contact area with the inner tube, which is conducive to improving the heat conduction effect, thereby improving the accuracy of controlling the cooling rate. In addition, the intermediate cylinder of the silicon carbide crystal growth furnace adopts a parallel water channel design, which optimizes the distribution of the temperature gradient, is conducive to reducing the internal defects of the silicon carbide crystal, and improves the yield rate of the silicon carbide crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a stereogram of an embodiment of the utility model.

[0019] Figure 2 yes Figure 1 A magnified partial view of point A in the middle.

[0020] Figure 3 It is a cross-sectional view of an embodiment of the utility model.

[0021] Figure 4 yes Figure 3 A magnified partial view of point B in the middle.

[0022] Figure 5 yes Figure 3 A magnified partial view of point C in the middle.

[0023] Figure 6 It is a stereoscopic diagram of an embodiment of the utility model with the outer tube, the water inlet tube and the water outlet tube removed.

[0024] Figure 7 yes Figure 6 main view.

[0025] Figure 8 It is a structural diagram of an open ring in an embodiment of the utility model.

[0026] Fig. 9 It is a schematic diagram of the embodiment of the utility model in actual use.

[0027] The following are the descriptions of the reference numerals:

[0028] In the figure: 1, inner tube; 2, first flange; 201, first ring groove; 3, second flange; 301, second ring groove; 4, outer tube; 5, wire rod; 501, open ring; 5011, notch; 5012, head end; 5013, tail end; 502, inclined plate; 6, water inlet pipe; 7, water outlet pipe; 8, first connector; 9, second connector; 10, section; 11, first sealing ring; 12, second sealing ring; 13, graphite thermal field; 14, cylinder cover; 15, vacuum chamber; 16, water channel. DETAILED DESCRIPTION

[0029] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions of the following examples and the accompanying drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application. The present application can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0030] The present application provides these embodiments to make the present application thorough and complete, and to fully express the scope of the present application to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0031] It should be noted that, in the description of this application, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0032] In addition, the words "first", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0033] It should also be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0034] All terms used in this application have the same meaning as those understood by those of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0035] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0036] See also Figure 1-Figure 8 As shown, the utility model provides an intermediate cylinder of a silicon carbide crystal growth furnace, comprising an inner tube 1, a first flange 2, a second flange 3, an outer tube 4 and a wire rod 5. Figure 1 As shown, the inner tube 1 is a circular tube, the shape and size of the inner tube 1 match the graphite thermal field 13, the first flange 2 is seamlessly welded to one end of the inner tube 1, and the second flange 3 is seamlessly welded to the other end of the inner tube 1; the outer tube 4 is sleeved on the outside of the inner tube 1, and there is a gap between the inner wall of the outer tube 4 and the outer wall of the inner tube 1, and the two ends of the outer tube 4 are seamlessly welded to the first flange 2 and the second flange 3 respectively, and the tube wall of the outer tube 4 is provided with a water inlet adjacent to the first flange 2 and a water outlet adjacent to the second flange 3, and the water inlet and the water outlet are both connected to the aforementioned gap; the wire rod 5 is wound on the outer wall of the inner tube 1, and the outer edge of the wire rod 5 is seamlessly connected to the outer tube 4, and the wire rod 5 divides the gap between the outer tube 4 and the inner tube 1 into a water channel 16 surrounding the inner tube 1, and the end of the water channel 16 adjacent to the first flange 2 is the water inlet end, and the end of the water channel 16 adjacent to the second flange 3 is the water outlet end, the water inlet is connected to the water inlet end of the water channel 16, and the water outlet is connected to the water outlet end of the water channel 16.

[0037] The middle cylinder of the silicon carbide crystal growth furnace divides the gap between the inner tube 1 and the outer tube 4 into a water channel 16 through the wire rod 5. The water channel 16 formed in this way has a larger contact area with the inner tube 1, which is beneficial to improving the heat conduction effect, thereby improving the accuracy of controlling the cooling rate.

[0038] In some embodiments, both ends of the wire rod 5 are connected to the first flange 2 and the second flange 3 respectively. Figure 7 As shown, the upper end of the wire rod 5 is connected to the first flange 2 , and the lower end of the wire rod 5 is connected to the second flange 3 .

[0039] In some embodiments, the outer tube 4 is in a circular tube shape and is coaxial with the inner tube 1, and the inner diameter of the outer tube 4 is greater than the outer diameter of the inner tube 1. By making the inner tube 1 and the outer tube 4 coaxial, the outer wall of the inner tube 1 and the inner wall of the outer tube 4 can have the same gap at different positions, thereby ensuring that all parts of the inner tube 1 can dissipate heat evenly.

[0040] In some embodiments, the wire rod 5 includes an open ring 501 and an inclined plate 502. The open ring 501 is roughly annular and is provided with a notch 5011. A plurality of open rings 501 are evenly spaced along the axis of the inner tube 1. The plurality of open rings 501 are connected end to end in sequence through the inclined plate 502. The head end 5012 of the open ring 501 adjacent to the first flange 2 is connected to the first flange 2 through an inclined plate 502, and the tail end 5013 of the open ring 501 adjacent to the second flange 3 is connected to the second flange 3 through an inclined plate 502. The inner edge of the open ring 501 is seamlessly connected to the outer wall of the inner tube 1, and the outer edge of the open ring 501 is seamlessly connected to the inner wall of the outer tube 4. After the notch 5011 is provided on the open ring 501, the shape of the open ring 501 is as follows: Figure 8 As shown, the open ring 501 has a head end 5012 and a tail end 5013, and the open ring 501 is sleeved on the outer side of the inner tube 1. The inner diameter of the open ring 501 is equal to the outer diameter of the inner tube 1, and the outer diameter of the open ring 501 is equal to the inner diameter of the outer tube 4. After the open ring 501 is installed on the inner tube 1, the notches 5011 on all the open rings 501 are aligned along the axis direction of the inner tube 1. It is worth noting that the connection between the inclined plate 502 and the open ring 501 can be a smooth transition, thereby ensuring that the structure of the water channel 16 conforms to the fluid design curve and reducing the resistance of the water channel 16.

[0041] In some embodiments, the plane where each open ring 501 is located is perpendicular to the axis of the inner tube 1. Figure 7 As shown in the figure, the axis of the inner tube 1 is perpendicular to the horizontal plane, and all the open rings 501 are parallel to the horizontal plane, thus forming multiple layers of water channels 16 arranged from top to bottom, and most of the water channels 16 in each layer are located at the same height, and the water channels 16 of two adjacent layers are connected at the position of the inclined plate 502. Such a structural design can make the middle cylinder of the silicon carbide crystal growth furnace have approximately the same temperature at the same height position, thereby further optimizing the distribution of the temperature gradient, which is beneficial to reducing the defects inside the silicon carbide crystal and improving the yield rate of the silicon carbide crystal.

[0042] In some embodiments, the middle cylinder of the silicon carbide crystal growth furnace also includes an inlet pipe 6 and an outlet pipe 7, wherein the inlet pipe 6 is connected to the water inlet, and the outlet pipe 7 is connected to the water outlet. The inlet pipe 6 and the outlet pipe 7 are both hollow round tubes, and the inlet pipe 6 and the outlet pipe 7 can have the same inner diameter and wall thickness. One end of the inlet pipe 6 is inserted into the water inlet and welded to the outer tube 4, and one end of the outlet pipe 7 is inserted into the water outlet and welded to the outer tube 4. In this embodiment, the pipeline can be directly connected to the inlet pipe 6 and the outlet pipe 7 when in use, which is more convenient to use. In the utility model, the connection position of the inlet pipe 6 and the outer tube 4 is the position of the water inlet, and the connection position of the outlet pipe 7 and the outer tube 4 is the position of the water outlet. The positions of the water inlet and the water inlet are not marked in the accompanying drawings.

[0043] In some embodiments, the middle cylinder of the silicon carbide crystal growth furnace further includes a first connector 8 connected to the water inlet pipe 6 and a second connector 9 connected to the water outlet pipe 7. The first connector 8 and the second connector 9 are both in the shape of a circular tube. The outer diameter of the first connector 8 is greater than the outer diameter of the water inlet pipe 6, and the outer diameter of the second connector 9 is greater than the outer diameter of the water outlet pipe 7. The first connector 8 and the second connector 9 are welded to the water inlet pipe 6 and the water outlet pipe 7, respectively. In this embodiment, the pipes can be threadedly connected to the first connector 8 and the second connector 9 when in use. At this time, the connected pipes have a relatively large diameter, which is conducive to ensuring the stability of the water flow.

[0044] In some embodiments, the outer circumferential walls of the first connector 8 and the second connector 9 are each provided with four equidistantly spaced cut surfaces 10, and the cut surfaces 10 can be processed by cutting. In the process of connecting the pipes to the connectors, since the water inlet pipe 6 and the water outlet pipe 7 are thin and cannot withstand large forces, an open-end wrench can be used to clamp the two cut surfaces 10 to prevent the water inlet pipe 6 and the water outlet pipe 7 from being subjected to force during assembly, thereby avoiding damage to the water inlet pipe 6 and the water outlet pipe 7. In other embodiments, the outer circumferential walls of the first connector 8 and the second connector 9 are each provided with two equidistantly spaced cut surfaces 10, and the two cut surfaces 10 are parallel to each other.

[0045] In some embodiments, a first annular groove 201 is provided on the end surface of the first flange 2, and a first sealing ring 11 made of rubber material is provided in the first annular groove 201; a second annular groove 301 is provided on the end surface of the second flange 3, and a second sealing ring 12 made of rubber material is provided in the second annular groove 301.

[0046] In the specific implementation, all the parts that need to be sealed in the middle cylinder of the silicon carbide crystal growth furnace are all processed by CNC, and the processing accuracy is strictly controlled; at the same time, all parts are made of high-quality 304 stainless steel, and the inner wall is polished smooth to reduce the adhesion of gas and reduce the residual active gas in the middle cylinder of the silicon carbide crystal growth furnace. TIG welding is used for sealing welding, and there are welding points between the wire rod 5 and the inner tube 1 and the outer tube 4 to ensure that the middle cylinder of the silicon carbide crystal growth furnace has sufficient strength and pressure resistance.

[0047] Fig. 9 The diagram is a schematic diagram of the use of the middle cylinder of the silicon carbide crystal growth furnace. When in use, the graphite thermal field 13 is inserted into the inner tube 1 of the middle cylinder of the silicon carbide crystal growth furnace, and then the cylinder cover 14 is connected to the first flange 2, and the vacuum chamber 15 is connected to the second flange 3. In some embodiments, the sealing effect between the cylinder cover 14 and the first flange 2 can be improved by the first sealing ring 11, and the second sealing ring 12 can be improved by the second flange 3 and the vacuum chamber 15.

[0048] In the utility model, the gap between the inner tube 1 and the outer tube 4 is divided into a water channel 16 by the wire rod 5, so that the formed water channel 16 has a larger contact area with the inner tube 1, which is conducive to improving the heat conduction effect, thereby improving the accuracy of controlling the cooling speed. In addition, the middle cylinder of the silicon carbide crystal growth furnace adopts a parallel water channel 16 design, which optimizes the distribution of the temperature gradient, is conducive to reducing the internal defects of the silicon carbide crystal, and improves the yield rate of the silicon carbide crystal.

[0049] So far, various embodiments of the present application have been described in detail. In order to avoid obscuring the concept of the present application, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed herein.

[0050] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. An intermediate cylinder of a silicon carbide crystal growth furnace, characterized in that: include: An inner tube (1), wherein the inner tube (1) is in the shape of a circular tube; A first flange (2), wherein the first flange (2) is seamlessly connected to one end of the inner tube (1); A second flange (3), wherein the second flange (3) is seamlessly connected to the other end of the inner tube (1); an outer tube (4), the outer tube (4) being sleeved on the outer side of the inner tube (1), the two ends of the outer tube (4) being seamlessly connected to the first flange (2) and the second flange (3) respectively, and the tube wall of the outer tube (4) being provided with a water inlet adjacent to the first flange (2) and a water outlet adjacent to the second flange (3); and A wire rod (5), the wire rod (5) is wound on the outer wall of the inner tube (1), and the outer edge of the wire rod (5) is seamlessly connected to the outer tube (4).

2. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 1, characterized in that: Two ends of the wire rod (5) are respectively connected to the first flange (2) and the second flange (3).

3. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 1, characterized in that: The outer tube (4) is in the shape of a circular tube and is coaxial with the inner tube (1).

4. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 1, characterized in that: The wire rod (5) comprises an open ring (501) and an inclined plate (502); the open ring (501) is roughly in the shape of a circular ring and is provided with a notch (5011); a plurality of the open rings (501) are equidistantly spaced along the axial direction of the inner tube (1); the plurality of the open rings (501) are connected end to end in sequence through the inclined plate (502); the head end of the open ring (501) adjacent to the first flange (2) is connected to the first flange (2) through the inclined plate (502); the tail end of the open ring (501) adjacent to the second flange (3) is connected to the second flange (3) through the inclined plate (502); the inner edge of the open ring (501) is seamlessly connected to the outer wall of the inner tube (1); and the outer edge of the open ring (501) is seamlessly connected to the inner wall of the outer tube (4).

5. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 4, characterized in that: The plane where each open ring (501) is located is perpendicular to the axis of the inner tube (1).

6. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 1, characterized in that: It also comprises a water inlet pipe (6) and a water outlet pipe (7), wherein the water inlet pipe (6) is connected to the water inlet, and the water outlet pipe (7) is connected to the water outlet.

7. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 6, characterized in that: It also comprises a first connector (8) connected to the water inlet pipe (6) and a second connector (9) connected to the water outlet pipe (7), wherein the outer diameter of the first connector (8) is greater than the outer diameter of the water inlet pipe (6), and the outer diameter of the second connector (9) is greater than the outer diameter of the water outlet pipe (7).

8. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 7, characterized in that: Two or four equidistantly spaced cut surfaces (10) are provided on the outer peripheral walls of the first connecting head (8) and the second connecting head (9).

9. The intermediate cylinder of the silicon carbide crystal growth furnace according to claim 1, characterized in that: A first annular groove (201) is provided on the end surface of the first flange (2), a first sealing ring (11) is provided in the first annular groove (201), and a second annular groove (301) is provided on the end surface of the second flange (3), a second sealing ring (12) is provided in the second annular groove (301).

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