Furnace chamber structure and crystal growing furnace adapted to production of multi-size silicon carbide single crystals

Abstract

The application provides a furnace cavity structure suitable for production of multi-size silicon carbide single crystals and a crystal growth furnace, and relates to the technical field of silicon carbide single crystal growth. The furnace cavity structure suitable for production of multi-size silicon carbide single crystals comprises a furnace shell and an adjusting plate, the furnace shell is provided with a long hole in the height direction of the furnace shell, the adjusting plate is installed at the long hole and detachably connected with the furnace shell, and the adjusting plate is provided with an electrode mounting hole arranged opposite to the long hole. The furnace cavity structure suitable for production of multi-size silicon carbide single crystals is convenient for personnel operation, reduces production cost, and improves production flexibility and convenience.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide single crystal growth technology, and in particular to a furnace cavity structure and crystal growth furnace adapted to the production of multi-size silicon carbide single crystals. Background Technology

[0002] With the development of semiconductor technology, silicon carbide (SiC), as a wide-bandgap semiconductor material, has been widely used in power electronic devices and other fields due to its excellent physical and electrical properties. Silicon carbide single crystals are typically grown using the physical vapor transport (PVT) method. Specifically, this process takes place in a sealed graphite crucible. The raw material powder is placed at the bottom of the crucible, and under the high-temperature environment provided by the crystal growth furnace, the raw material sublimates to form a gaseous substance that migrates upwards and recrystallizes at the slightly cooler seed crystal, thus achieving the growth of a silicon carbide single crystal. This method can effectively control the crystal growth rate and quality, meeting the requirements of different application scenarios for silicon carbide materials.

[0003] In existing technologies, the crystal growth furnace, as one of the key pieces of equipment for silicon carbide single crystal growth, directly affects the quality of the crystal and production efficiency. However, existing crystal growth furnace designs still have some shortcomings. For example, a fixed-height electrode mounting port is provided on the side of the furnace shell, with the electrode installed at the port positioned opposite the power supply port inside the furnace. Since silicon carbide single crystals come in various sizes, including six-inch, eight-inch, and twelve-inch, the required thermal field size varies for different sizes, which may lead to variations in the height of the power supply port. If a fixed electrode mounting port is used, different furnace shells need to be replaced to accommodate the production needs of different silicon carbide single crystal sizes, which not only increases costs but also reduces production flexibility and convenience.

[0004] Furthermore, existing crystal growth furnaces have three electrodes at the bottom, which are connected to a single lower flange that is fixedly mounted on the furnace body. When producing silicon carbide single crystals of different sizes, the traditional approach is to replace the entire furnace cavity structure to accommodate the different electrode spacings in order to adjust the thermal field size to meet different production requirements. This method also leads to inconvenience in the production process, limits the compatibility of the crystal growth furnace with the production of silicon carbide single crystals of different sizes, and thus affects the overall production efficiency and cost-effectiveness.

[0005] Therefore, how to provide a furnace cavity structure and crystal growth furnace that can improve production flexibility is one of the technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a furnace cavity structure suitable for the production of silicon carbide single crystals of various sizes, which facilitates operation, reduces production costs, and improves production flexibility and convenience. Additionally, a crystal growth furnace including the above-mentioned furnace cavity structure is provided.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a furnace cavity structure adapted for the production of multi-size silicon carbide single crystals, including a furnace shell and an adjustment plate. The furnace shell has an elongated hole along its own height direction. The adjustment plate is installed at the elongated hole and is detachably connected to the furnace shell. The adjustment plate has an electrode mounting hole arranged opposite to the elongated hole.

[0009] Furthermore, the adjusting plate and the furnace shell are detachably connected by a connector. The adjusting plate is provided with a plurality of first connecting holes, and the furnace shell is provided with a wing plate at the edge corresponding to the elongated hole. The wing plate is provided with a plurality of second connecting holes that correspond one-to-one with the plurality of first connecting holes. The connector passes through the first connecting hole and is inserted into the second connecting hole.

[0010] Furthermore, a first sealing element is provided between the adjusting plate and the wing plate.

[0011] Furthermore, the adjusting plate includes an inner plate, an outer plate, an inner flange, and an outer flange;

[0012] The inner plate is detachably connected to the furnace shell, and the outer plate is installed on the side of the inner plate away from the furnace shell;

[0013] The inner flange is installed between the inner plate and the outer plate, and the outer flange is installed on the side of the outer plate away from the inner plate. The electrode mounting hole is formed between the inner flange and the outer flange.

[0014] Furthermore, a cooling cavity is formed between the inner plate, the outer plate, and the inner flange.

[0015] Furthermore, it also includes a flange assembly that is detachably connected to the bottom of the furnace shell, and the flange assembly is equipped with multiple electrodes.

[0016] Furthermore, the flange assembly includes a first flange and a second flange, the first flange being detachably connected to the bottom of the furnace shell, the second flange being detachably connected to the bottom of the first flange, and the second flange being equipped with a plurality of the electrodes.

[0017] Furthermore, a second sealing element is provided between the first flange and the furnace shell, and a third sealing element is provided between the second flange and the first flange.

[0018] Furthermore, it also includes a heat preservation plate, with a limiting groove formed between the first flange and the second flange, and the bottom of the heat preservation plate located in the limiting groove, thereby limiting the position of the heat preservation plate relative to the furnace shell.

[0019] Secondly, the present invention provides a crystal growth furnace, including the furnace cavity structure described above.

[0020] The furnace cavity structure and crystal growth furnace adapted for the production of multi-size silicon carbide single crystals provided by this invention can produce the following beneficial effects:

[0021] In the furnace cavity structure provided by the present invention, when the height of the power supply port changes, since the adjustment plate is detachably connected to the furnace shell, personnel can replace different adjustment plates to adjust the height of the electrode mounting hole. Furthermore, since the furnace shell has elongated holes along its own height direction, even if the height of the electrode mounting hole changes, the electrode can still supply power to the power supply port through the elongated holes.

[0022] Compared with the prior art, the furnace cavity structure provided by the first aspect of the present invention can be adapted to the production needs of silicon carbide single crystals of different sizes by replacing the adjustment plate, which facilitates personnel operation, reduces production costs, and improves the flexibility and convenience of production.

[0023] The crystal growth furnace provided in the second aspect of the present invention has the furnace cavity structure provided in the first aspect of the present invention, and thus has all the beneficial effects of the furnace cavity structure provided in the first aspect of the present invention. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 A partial cross-sectional view of a crystal growth furnace provided in an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A magnified view of part A;

[0027] Figure 3 This is a three-dimensional structural diagram of an adjustment plate and a connector connected according to an embodiment of the present invention;

[0028] Figure 4 This is a three-dimensional structural diagram of a crystal growth furnace from a first-view perspective, provided as an embodiment of the present invention.

[0029] Figure 5 This is a three-dimensional structural diagram of a crystal growth furnace from a second perspective, provided as an embodiment of the present invention.

[0030] Icons: 1 - Furnace shell; 11 - Long strip hole; 12 - Wing plate; 13 - Bottom plate; 2 - Adjusting plate; 21 - Inner plate; 22 - Outer plate; 23 - Inner flange; 24 - Outer flange; 25 - Cooling chamber; 26 - Electrode mounting hole; 3 - Connector; 4 - First seal; 5 - Flange assembly; 51 - First flange; 52 - Second flange; 6 - Electrode; 7 - Second seal; 8 - Third seal; 9 - Insulation plate; 10 - Upper graphite heater; 011 - Lower graphite heater; 012 - Insulation barrel; 013 - First insulating ring. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0035] A first aspect of the present invention provides a furnace cavity structure adapted for the production of multi-size silicon carbide single crystals, such as... Figure 1 and Figure 2 As shown, the furnace includes a furnace shell 1 and an adjusting plate 2. The furnace shell 1 has an elongated hole 11 along its height direction. The adjusting plate 2 is installed at the elongated hole 11 and is detachably connected to the furnace shell 1. The adjusting plate 2 has an electrode mounting hole 26 that is opposite to the elongated hole 11.

[0036] like Figure 1 and Figure 2 As shown, the furnace cavity structure provided by the first aspect of the present invention is free from the traditional method of setting fixed electrode mounting holes on the furnace shell. Instead, an elongated hole 11 is set along the height direction of the furnace shell 1. A detachable adjustment plate 2 is designed at the corresponding elongated hole 11. When the required thermal field changes, different adjustment plates 2 can be replaced to achieve the purpose of adjusting the height of the electrode mounting hole 26. Since the elongated hole 11 extends along the height direction of the furnace shell 1, the electrode after the height adjustment can still feed power to the power supply port through the elongated hole.

[0037] Therefore, the furnace cavity structure provided by the first aspect of the present invention can be adapted to the production needs of silicon carbide single crystals of different sizes by replacing the adjustment plate 2, which facilitates personnel operation and improves work efficiency, production flexibility and convenience.

[0038] The number of elongated holes 11 is related to the number of electrodes 6 on the side of the furnace shell 1, specifically, the number of elongated holes 11 is equal to the number of electrodes 6 on the side of the furnace shell 1. When there are three electrodes 6 on the side of the furnace shell 1, the furnace shell 1 is equipped with three elongated holes 11, and the three elongated holes 11 are evenly spaced around the axis of the furnace shell 1.

[0039] In addition, the shape of the elongated hole 11 can be a rectangular hole, an oblong hole, etc.

[0040] In other words, the shape of the elongated hole 11 is not specifically limited, as long as the elongated hole 11 extends to a certain length in the height direction of the furnace shell 1.

[0041] There are several ways to detachably connect the adjusting plate 2 and the furnace shell 1. For example, the adjusting plate 2 and the furnace shell 1 can be connected by a snap-fit ​​method, specifically by setting a snap-fit ​​structure on the edge of the adjusting plate 2 and setting a corresponding slot on the furnace shell 1 at the corresponding position; or the adjusting plate 2 and the furnace shell 1 can be connected by a pin, specifically by installing a pin on the adjusting plate 2 and setting a corresponding insertion hole on the furnace shell 1.

[0042] In an optional embodiment, to ensure the firmness of the connection between the adjusting plate 2 and the furnace shell 1, such as... Figure 4As shown, the adjusting plate 2 and the furnace shell 1 are detachably connected by a connector 3, which can be a screw. The adjusting plate 2 is provided with multiple first connecting holes. The furnace shell 1 is provided with a wing plate 12 at the edge of the elongated hole 11. The wing plate 12 is provided with multiple second connecting holes that correspond one-to-one with the multiple first connecting holes. The connector 3 passes through the first connecting hole and is inserted into the second connecting hole.

[0043] Taking the connector 3 as an example, when in use, the screw can be passed through the first connecting hole and tightened into the second connecting hole to connect the adjusting plate 2 and the wing plate 12. When the adjusting plate 2 needs to be replaced, the screw can be loosened.

[0044] The use of screws in connector 3 not only facilitates the connection between the adjusting plate 2 and the wing plate 12, but also ensures the firmness of the connection between the two. The pressure applied by the adjusting plate 2 to the wing plate 12 is also easy to adjust.

[0045] Specifically, multiple connectors 3 are configured, and the multiple connectors 3 are evenly spaced along the wing plate 12.

[0046] In alternative implementations, such as Figure 2 As shown, a first sealing element 4 is provided between the adjusting plate 2 and the wing plate 12. The first sealing element 4 can ensure the sealing between the adjusting plate 2 and the wing plate 12.

[0047] Specifically, the first sealing element 4 is a sealing ring, and the surface of the wing plate 12 facing the adjusting plate 2 may be provided with a concave sealing groove, and the sealing ring is installed in the sealing groove.

[0048] To ensure the stability of the sealing ring within the groove, a dovetail groove is preferred.

[0049] In alternative implementations, such as Figure 2 and Figure 3 As shown, the adjusting plate 2 includes an inner plate 21, an outer plate 22, an inner flange 23, and an outer flange 24, wherein:

[0050] The inner plate 21 is detachably connected to the furnace shell 1. The outer plate 22 is installed on the side of the inner plate 21 away from the furnace shell 1. The outer plate 22 and the inner plate 21 can be connected by welding or other means. The inner flange 23 is installed between the inner plate 21 and the outer plate 22. The outer flange 24 is installed on the side of the outer plate 22 away from the inner plate 21. An electrode mounting hole 26 is formed between the inner flange 23 and the outer flange 24.

[0051] Specifically, the inner flange 23 can be welded between the inner plate 21 and the outer plate 22, and the outer flange 24 can be welded to the side of the outer plate 22 away from the inner plate 21, thus ensuring the sealing between the flange and the plate.

[0052] In alternative implementations, such as Figure 2As shown, a cooling chamber 25 is formed between the inner plate 21, the outer plate 22 and the inner flange 23. A cooling medium can be circulated in the cooling chamber 25 to cool the regulating plate 2.

[0053] When the inner flange 23 is welded between the inner plate 21 and the outer plate 22, and the outer flange 24 is welded to the side of the outer plate 22 away from the inner plate 21, compared with the connection method using screws or other fasteners, it can ensure absolute sealing between the plate and the flange, and no gap will be generated at the connection. The cooling chamber 25 has good sealing performance and avoids water leakage.

[0054] Specifically, the cooling chamber 25 has an inlet and an outlet. The inlet is located on the lower side of the cooling chamber 25, and the outlet is located on the upper side of the cooling chamber 25, so as to realize the bottom inlet and top outlet of cooling water.

[0055] Additionally, as Figure 1 As shown, the furnace shell 1 is equipped with an upper graphite heater 10 and a lower graphite heater 011. The two work together to heat the crystal growth cavity. Therefore, the temperature inside the furnace cavity usually reaches 2200℃ during operation. To avoid the furnace shell 1 from getting too hot, a cooling channel is provided inside the furnace shell 1. The cooling medium can cool the furnace shell 1 through the cooling channel.

[0056] like Figure 2 As shown, a first insulating ring 013 is fixedly installed inside the electrode mounting hole 26, and the first insulating ring 013 is sleeved on the outside of the electrode 6.

[0057] The material of the first insulating ring 013 may be, but is not limited to, ceramic.

[0058] In addition, the first insulating ring 013 has a circular structure to facilitate the installation of the electrode 6.

[0059] In alternative implementations, such as Figure 1 As shown, the furnace cavity structure also includes a flange assembly 5, which is detachably connected to the bottom of the furnace shell 1, and the flange assembly 5 is equipped with multiple electrodes 6.

[0060] In the above embodiments, since the flange assembly 5 is detachably connected to the bottom of the furnace shell 1, when it is necessary to adjust the hole spacing between the electrodes 6, it is not necessary to replace the entire furnace cavity structure. Only the flange assembly 5 needs to be disassembled and then replaced with a new flange assembly 5 with a different electrode hole spacing, which facilitates personnel operation. In particular, when used with the adjustment plate 2, when dealing with the production of silicon carbide single crystals of different sizes, only the flange assembly 5 and the adjustment plate 2 need to be replaced, which improves the overall production efficiency and cost-effectiveness.

[0061] For example, when it is necessary to change the produced silicon carbide single crystal product from six-inch to eight-inch, the required thermal field increases, the feed port position rises, and the distance between the electrodes 6 on the flange assembly 5 increases. In this case, a new adjusting plate 2 can be replaced to raise the position of the electrode mounting holes 26, and a new flange assembly 5 with a greater distance between the electrodes 6 can be used, thereby creating a larger thermal field within the furnace cavity structure. This process does not require replacing the entire furnace cavity structure, facilitating personnel operation and improving work efficiency, production flexibility, and convenience. The same principle applies when changing the produced silicon carbide single crystal product from eight-inch to twelve-inch; therefore, the above furnace cavity structure is suitable for the growth of six- to twelve-inch silicon carbide single crystals.

[0062] Specifically, the flange assembly 5 can be detachably connected to the furnace shell 1 in various ways, such as by clamping the flange assembly 5 to the furnace shell 1 with claws, or by connecting the flange assembly 5 to the furnace shell 1 with pins, and so on.

[0063] In a preferred embodiment, the flange assembly 5 is detachably connected to the furnace shell 1 by screws, which facilitates personnel operation while ensuring the stability of the connection between the flange assembly 5 and the furnace shell 1. Multiple screws are configured, and these screws are evenly spaced around the axis of the furnace shell 1.

[0064] In alternative implementations, such as Figure 1 and Figure 5 As shown, the flange assembly 5 includes a first flange 51 and a second flange 52. The first flange 51 is detachably connected to the bottom of the furnace shell 1. The bottom of the furnace shell 1 is also detachably connected to a base plate 13. The second flange 52 is detachably connected to the bottom of the first flange 51. The second flange 52 is equipped with multiple electrodes 6. A second insulating ring is provided between each electrode 6 and the second flange 52.

[0065] In the above embodiments, the flange assembly 5 includes a first flange 51 and a second flange 52. Not only can the first flange 51 be detached from the bottom of the furnace shell 1, but the second flange 52 can also be detached from the bottom of the first flange 51. The flange structure at the bottom of the furnace shell 1 can be adjusted by matching the first flange 51 and the second flange 52 of different sizes or models to adapt to the needs of different thermal fields, making the adjustment more flexible.

[0066] The detachable connection method between the first flange 51 and the second flange 52 is similar to the detachable connection method between the first flange 51 and the furnace shell 1. To save space, examples will not be given here.

[0067] To prevent the first flange 51 and the second flange 52 from overheating, cooling channels are also provided inside the first flange 51 and the second flange 52. The cooling channels can be spiral-shaped, and the cooling medium can cool the first flange 51 and the second flange 52 through the cooling channels.

[0068] In an optional implementation, to ensure the sealing between the flange assembly 5 and the furnace shell 1, as well as the flange assembly itself, such as Figure 1 As shown, a second sealing element 7 is provided between the first flange 51 and the furnace shell 1, and a third sealing element 8 is provided between the second flange 52 and the first flange 51.

[0069] The second sealing element 7 and the third sealing element 8 can be sealing rings. The furnace shell 1 can be provided with a concave sealing groove. The second sealing element 7 is installed in the concave sealing groove. The outer edge of the second flange 52 is provided with a countersunk platform. The third sealing element 8 is sandwiched between the countersunk platform and the first flange 51.

[0070] To ensure the stability of the second seal 7 within the groove, the sealing groove is preferably a dovetail groove.

[0071] In alternative implementations, such as Figure 1 As shown, in order to reduce the loss of temperature in the furnace cavity, the furnace cavity structure also includes a heat preservation barrel 012 and a heat preservation plate 9. The heat preservation barrel 012 is set inside the furnace shell 1 and located outside the upper graphite heater 10 and the lower graphite heater 011. A limiting groove is formed between the first flange 51 and the second flange 52. The bottom of the heat preservation plate 9 is located in the limiting groove, thereby limiting the position of the heat preservation plate 9 relative to the furnace shell 1.

[0072] In the above embodiments, the second flange 52 not only supports the insulation plate 9, but the cooperation between the second flange 52 and the first flange 51 can also achieve radial positioning of the insulation plate 9. Different cooperation between the second flange 52 and the first flange 51 can also be adapted to insulation plates 9 of different sizes.

[0073] A second aspect of the present invention provides a crystal growth furnace, which includes the above-described furnace cavity structure.

[0074] The crystal growth furnace provided in the second aspect of the present invention has the furnace cavity structure provided in the embodiments of the first aspect of the present invention, thereby having all the beneficial effects of the furnace cavity structure provided in the embodiments of the first aspect of the present invention.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A furnace cavity structure adapted for the production of multi-size silicon carbide single crystals, characterized in that, It includes a furnace shell (1) and an adjusting plate (2). The furnace shell (1) has an elongated hole (11) along its height direction. The adjusting plate (2) is installed at the elongated hole (11) and is detachably connected to the furnace shell (1). The adjusting plate (2) has an electrode mounting hole (26) opposite to the elongated hole (11). The regulating plate (2) includes an inner plate (21), an outer plate (22), an inner flange (23), and an outer flange (24); The inner plate (21) is detachably connected to the furnace shell (1), and the outer plate (22) is installed on the side of the inner plate (21) away from the furnace shell (1); The inner flange (23) is welded between the inner plate (21) and the outer plate (22), and the outer flange (24) is welded to the side of the outer plate (22) away from the inner plate (21). The electrode mounting hole (26) is formed between the inner flange (23) and the outer flange (24). A cooling cavity (25) is formed between the inner plate (21), the outer plate (22), and the inner flange (23).

2. The furnace cavity structure according to claim 1, characterized in that, The adjusting plate (2) and the furnace shell (1) are detachably connected by a connector (3). The adjusting plate (2) is provided with a plurality of first connecting holes. The furnace shell (1) is provided with a wing plate (12) at the edge of the elongated hole (11). The wing plate (12) is provided with a plurality of second connecting holes that correspond one-to-one with the plurality of first connecting holes. The connector (3) passes through the first connecting hole and is inserted into the second connecting hole.

3. The furnace cavity structure according to claim 2, characterized in that, A first seal (4) is provided between the adjusting plate (2) and the wing plate (12).

4. The furnace cavity structure according to any one of claims 1-3, characterized in that, It also includes a flange assembly (5) which is detachably connected to the bottom of the furnace shell (1) and is equipped with a plurality of electrodes (6).

5. The furnace cavity structure according to claim 4, characterized in that, The flange assembly (5) includes a first flange (51) and a second flange (52). The first flange (51) is detachably connected to the bottom of the furnace shell (1), and the second flange (52) is detachably connected to the bottom of the first flange (51). The second flange (52) is equipped with a plurality of electrodes (6).

6. The furnace cavity structure according to claim 5, characterized in that, A second sealing element (7) is provided between the first flange (51) and the furnace shell (1), and a third sealing element (8) is provided between the second flange (52) and the first flange (51).

7. The furnace cavity structure according to claim 5, characterized in that, It also includes a heat preservation plate (9), a limiting groove is formed between the first flange (51) and the second flange (52), the bottom of the heat preservation plate (9) is located in the limiting groove, thereby limiting the position of the heat preservation plate (9) relative to the furnace shell (1).

8. A crystal growth furnace, characterized in that, Includes the furnace cavity structure as described in any one of claims 1-7.

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