Sintering furnace and method for preparing tantalum carbide coating on graphite substrate surface

Abstract

The embodiment of the present application provides a sintering furnace and a method for preparing a tantalum carbide coating on the surface of a graphite substrate. The sintering furnace is used to sinter the tantalum carbide coating on the graphite substrate. The sintering furnace includes a furnace shell, a first electrode and a second electrode. A cavity is formed inside the furnace shell, and the cavity is configured as a accommodating space for sintering the graphite substrate. One end of the first electrode contacts one side of the graphite substrate, and one end of the second electrode contacts the other side of the graphite substrate. When a voltage is applied to the first electrode and the second electrode, the first electrode, the second electrode and the graphite substrate form a conductive circuit. The graphite substrate sintered by the sintering furnace in this embodiment will not suffer any loss itself, thereby ensuring the quality of subsequent crystal growth, thereby extending the service life of the graphite substrate, and since there is no need to set a heater, the production cost is effectively reduced, which is conducive to industrial production.

Description

Technical Field

[0001] The present application relates to the field of tantalum carbide coating preparation, and in particular to a sintering furnace and a method for preparing a tantalum carbide coating on the surface of a graphite substrate. Background Art

[0002] This section merely provides background information related to the present application and is not necessarily prior art.

[0003] In the related technology, graphite material devices are widely used in the field of semiconductor crystal growth, such as graphite heaters, graphite crucibles, fixtures, etc. Graphite material has many unique properties, such as: good conductor of heat and electricity, high chemical stability, high temperature resistance, small thermal expansion coefficient, strong thermal shock resistance, easy processing, cheaper than tungsten, molybdenum, tantalum, etc., and is an important inorganic non-metallic material.

[0004] The growth environment temperature of the third-generation semiconductor crystals is as high as 2100-2400℃, and there is a complex atmosphere in the small growth space. The sublimated source powder (silicon, aluminum) atmosphere has a high reactivity and can corrode graphite material devices. Particles on the surface of graphite material devices enter the crystal and cause crystal defects such as inclusions, which in turn have a significant impact on the performance and quality of the crystal and semiconductor. Adding tantalum carbide coating on the surface of graphite material can solve this problem well.

[0005] Tantalum carbide is a high-temperature ceramic material with a high melting point (3880°C), high strength and good chemical stability. It has excellent chemical corrosion resistance and oxidation resistance in high-temperature environments, making it suitable for use as a high-temperature coating on the surface of graphite material devices, giving the devices more excellent corrosion resistance and effectively protecting them. In the actual crystal growth of third-generation semiconductors, it reduces defects, improves crystal quality, increases the reuse rate of graphite material devices, and reduces production costs.

[0006] At present, the commonly used method for preparing tantalum carbide coating at low cost at home and abroad is: use tantalum carbide, sintering aid, adhesive and solvent to prepare suspension, spray or brush the suspension evenly on the surface of the graphite device, and finally preheat and sinter the device with the sprayed or brushed coating to obtain a layer of tantalum carbide coating on the device. This method inevitably requires sintering the graphite device with tantalum carbide suspension. The main sintering method is to use an external heater to heat around the device. The graphite material device directly faces the heating source, which is prone to local oxidation, reducing the service life of the graphite material parts and even affecting the quality of subsequent crystal growth. In addition, the external heater is prone to wear and tear after long-term use, resulting in increased costs. Therefore, how to extend the service life of graphite materials is a problem that needs to be solved at present. Summary of the invention

[0007] The purpose of this application is to provide a sintering furnace and a method for preparing a tantalum carbide coating on the surface of a graphite substrate to extend the service life of graphite devices. To achieve the above purpose, this application provides the following technical solutions:

[0008] The embodiment of the first aspect of the present application provides a sintering furnace for sintering a tantalum carbide coating on a graphite substrate. The sintering furnace includes a furnace shell, a first electrode, and a second electrode. A cavity is formed inside the furnace shell, and the cavity is configured as a accommodating space for sintering the graphite substrate. One end of the first electrode contacts one side of the graphite substrate, and one end of the second electrode contacts the other side of the graphite substrate. When a voltage is applied to the first electrode and the second electrode, the first electrode, the second electrode, and the graphite substrate form a conductive loop.

[0009] According to the sintering furnace in the embodiment of the present application, when sintering the graphite substrate, the graphite substrate coated with the tantalum carbide suspension can be placed in the cavity first, and then the part of the graphite substrate not coated with the tantalum carbide suspension is electrically connected to the first electrode and the second electrode respectively. When voltage is applied to the first electrode and the second electrode, the first electrode, the second electrode and the graphite substrate form a conductive circuit. Since the graphite substrate is made of graphite, the graphite substrate can generate heat when it is turned on, and then the graphite substrate coated with the tantalum carbide suspension is sintered by the self-heating of the graphite substrate. The graphite substrate sintered by the sintering furnace in this embodiment will not be damaged, which ensures the quality of subsequent crystal growth, and can extend the service life of the graphite substrate. Moreover, since there is no need to set a heater, the production cost is effectively reduced, which is conducive to industrial production.

[0010] In addition, according to the embodiments of the present application, the following additional technical features may also be provided:

[0011] In some embodiments of the present application, the furnace shell includes a first furnace cover, a second furnace cover and a side furnace barrel, the first furnace cover and the second furnace cover are respectively arranged at two ends of the side furnace barrel, and the first furnace cover, the second furnace cover and the side furnace barrel together form the cavity.

[0012] In some embodiments of the present application, the first electrode includes a first graphite electrode and a first metal electrode, the first graphite electrode and the first metal electrode are electrically connected, and the first graphite electrode is configured to be connected to a portion of the graphite substrate.

[0013] In some embodiments of the present application, the second electrode includes a second graphite electrode and a second metal electrode, the second graphite electrode and the second metal electrode are electrically connected, and the second graphite electrode is configured to be connected to a portion of the graphite substrate.

[0014] In some embodiments of the present application, the sintering furnace also includes a heat preservation chamber, which is arranged in the cavity, and a vacuum chamber is formed inside the heat preservation chamber. The heat preservation chamber also includes an air inlet and an air outlet connected to the vacuum chamber. The graphite substrate to be sintered is arranged in the vacuum chamber, and the first electrode and the second electrode pass through the heat preservation chamber to be connected to a part of the graphite substrate.

[0015] The embodiment of the second aspect of the present application provides a method for preparing a tantalum carbide coating on the surface of a graphite substrate, which is implemented based on the sintering furnace in any embodiment of the first aspect, and the steps of the method include:

[0016] Placing the graphite substrate coated with the tantalum carbide suspension in the sintering furnace;

[0017] Connecting the side of the graphite substrate that is not coated with the tantalum carbide suspension to the first electrode and the second electrode respectively;

[0018] A voltage is applied to the first electrode and the second electrode so that the first electrode, the second electrode, and the graphite substrate form a circuit.

[0019] In some embodiments of the present application, the sintering furnace further includes a heat preservation chamber, the heat preservation chamber is arranged in the cavity, a vacuum chamber is arranged inside the heat preservation chamber, and an air inlet and an air outlet communicated with the vacuum chamber, and the step of placing the graphite substrate coated with the tantalum carbide suspension in the sintering furnace includes:

[0020] The graphite substrate coated with the tantalum carbide suspension is placed in the vacuum chamber, and the vacuum chamber is placed in a vacuum state. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0022] Figure 1 It is a structural schematic diagram of a sintering furnace in the sintering process in the related art;

[0023] Figure 2 This is a schematic diagram of the structure of the sintering furnace during the sintering process in the embodiment of the present application;

[0024] Figure 3 This is a front view of the sintering furnace in the embodiment of the present application;

[0025] Figure 4 A top view of a sintering furnace in an embodiment of the present application;

[0026] Figure 5 for Figure 4 Sectional view along AA direction.

[0027] The symbols in the accompanying drawings are as follows:

[0028] 10-graphite substrate; 20-tantalum carbide suspension; 30-heater;

[0029] 100-furnace shell; 110-first furnace cover; 120-second furnace cover; 130-side furnace barrel; cavity-140;

[0030] 210 - first electrode; 211 - first metal electrode; 212 - first graphite electrode; 220 - second electrode; 221 - second metal electrode; 222 - second graphite electrode;

[0031] 300-heat preservation chamber; 310-vacuum chamber. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the embodiments of the present application 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 present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0033] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0035] In the related art, the commonly used method for preparing tantalum carbide coating at low cost at home and abroad is: use tantalum carbide, sintering aid, adhesive and solvent to prepare suspension, spray or brush the suspension evenly on the surface of the graphite device, and finally preheat and sinter the device with the sprayed or brushed coating to obtain a layer of tantalum carbide coating on the device. This method inevitably requires sintering the graphite device with tantalum carbide suspension. The main sintering method is to use an external heater to heat around the device. The graphite material device directly faces the heating source, which is prone to local oxidation, reducing the service life of the graphite material parts and even affecting the quality of subsequent crystal growth. In addition, the external heater is prone to wear and tear after long-term use, resulting in increased costs. Therefore, how to extend the service life of graphite materials is a problem that needs to be solved at present.

[0036] like Figure 1 As shown, a structural schematic diagram of using an external heater to heat a graphite device is illustrated. There is powdered material on the outer surface of the graphite device sintered in this way, that is, the graphite device sintered in this way will affect the crystal growth quality and reduce the service life of the graphite device. Moreover, the energy consumption of heating using an external heater is high, which inevitably increases the production cost.

[0037] like Figures 2 to 5 As shown, an embodiment of the first aspect of the present application provides a sintering furnace for sintering a tantalum carbide coating on a graphite substrate 10. The sintering furnace includes a furnace shell 100, a first electrode 210, and a second electrode 220. A cavity 140 is formed inside the furnace shell 100, and the cavity 140 is configured as a receiving space for sintering the graphite substrate 10. One end of the first electrode 210 contacts one side of the graphite substrate 10, and one end of the second electrode 220 contacts the other side of the graphite substrate 10. When a voltage is applied to the first electrode 210 and the second electrode 220, the first electrode 210, the second electrode 220 and the graphite substrate 10 form a conductive loop.

[0038] Please refer to Figure 2According to the sintering furnace in the embodiment of the present application, when sintering the graphite substrate 10, the graphite substrate 10 coated with the tantalum carbide suspension 20 can be placed in the cavity 140 first, and then the part of the graphite substrate 10 not coated with the tantalum carbide suspension 20 is electrically connected to the first electrode 210 and the second electrode 220 respectively. When voltage is applied to the first electrode 210 and the second electrode 220, the first electrode 210, the second electrode 220 and the graphite substrate 10 form a conductive loop. Since the graphite substrate 10 is made of graphite, the graphite substrate 10 can generate heat when it is turned on, and then the graphite substrate 10 coated with the tantalum carbide suspension is sintered by the self-heating of the graphite substrate 10. The graphite substrate 10 sintered by the sintering furnace in this embodiment will not be damaged, which ensures the quality of subsequent crystal growth, and can extend the service life of the graphite substrate 10. Moreover, since there is no need to set the heater 30, the production cost is effectively reduced, which is conducive to industrial production.

[0039] In some specific embodiments of the present application, the material of the graphite substrate 10 can be graphite or a carbon fiber reinforced carbon component.

[0040] Please refer to Figures 3 to 5 In some embodiments of the present application, the furnace shell 100 includes a first furnace cover 110, a second furnace cover 120 and a side furnace barrel 130. The first furnace cover 110 and the second furnace cover 120 are respectively arranged at both ends of the side furnace barrel 130. The first furnace cover 110, the second furnace cover 120 and the side furnace barrel 130 are surrounded to form a cavity 140. In this embodiment, the first furnace cover 110 can also be called an upper furnace cover, and the second furnace cover 120 can also be called a lower furnace cover. A seal can be provided between the first furnace cover 110 and the side furnace barrel 130 and between the second furnace cover 120 and the side furnace barrel 130 to ensure the sealing of the sintering furnace. When the graphite substrate 10 is sintered, the graphite substrate 10 to be sintered can be placed in the cavity 140 surrounded by the first furnace cover 110, the second furnace cover 120 and the side furnace barrel 130.

[0041] In some embodiments of the present application, the first electrode 210 includes a first graphite electrode 212 and a first metal electrode 211, the first graphite electrode 212 and the first metal electrode 211 are electrically connected, and the first graphite electrode 212 is configured to be connected to a portion of the graphite substrate 10. In this embodiment, the first metal electrode 211 may be a copper electrode, and copper may be used to make the first metal electrode 211 because of its low cost and excellent conductivity. The first metal electrode 211 and the first graphite electrode 212 may be connected in a detachable manner, for example, the first metal electrode 211 may be connected to the first graphite electrode 212 by a threaded fastening connection.

[0042] In some embodiments of the present application, the second electrode 220 includes a second graphite electrode 222 and a second metal electrode 221, the second graphite electrode 222 and the second metal electrode 221 are electrically connected, and the second graphite electrode 222 is configured to be connected to a portion of the graphite substrate 10. In this embodiment, the second metal electrode 221 may be a copper electrode, and copper may be used to make the second metal electrode 221 because of its low cost and excellent conductivity. The second metal electrode 221 and the second graphite electrode 222 may be connected in a detachable manner, for example, the second metal electrode 221 may be connected to the second graphite electrode 222 by a threaded fastening connection.

[0043] In some embodiments of the present application, the sintering furnace further includes a heat preservation chamber 300, which is disposed in the cavity 140, and a vacuum chamber 310 is formed inside the heat preservation chamber 300. The heat preservation chamber 300 also includes an air inlet and an air outlet communicated with the vacuum chamber 310. The graphite substrate 10 to be sintered is disposed in the vacuum chamber 310, and the first electrode 210 and the second electrode 220 pass through the heat preservation chamber and are connected to a portion of the graphite substrate 10. In this embodiment, the heat preservation chamber 300 may include a plurality of heat preservation side walls, and the plurality of heat preservation side walls enclose the vacuum chamber 310. The first electrode 210 and the second electrode 220 are both disposed in the heat preservation chamber 300 and are connected to the graphite substrate 10. By providing the heat preservation chamber 300, the graphite substrate 10 to be sintered can be placed in a relatively stable sintering environment. It can be understood that sintering needs to be carried out in a specific atmosphere or vacuum, so it is very important to control the gas phase partial pressure during the sintering process. When sintering the graphite substrate 10, an inert gas can be introduced through the air inlet or a vacuum chamber 310 can be formed inside the insulation cavity 300 through the air outlet, thereby ensuring the gas phase partial pressure during the sintering process, which is beneficial to the preparation of tantalum carbide coating on the surface of the graphite substrate 10.

[0044] The embodiment of the second aspect of the present application provides a method for preparing a tantalum carbide coating on the surface of a graphite substrate, which is implemented based on the sintering furnace in any one of the embodiments of the first aspect, and the steps of the method include:

[0045] S10, placing the graphite substrate 10 coated with the tantalum carbide suspension 20 in a sintering furnace;

[0046] S20, connecting the side of the graphite substrate 10 that is not coated with the tantalum carbide suspension 20 to the first electrode 210 and the second electrode 220 respectively;

[0047] S30 , applying a voltage to the first electrode 210 and the second electrode 220 so that the first electrode 210 , the second electrode 220 and the graphite substrate 10 form a loop.

[0048] According to a method for preparing a tantalum carbide coating on the surface of a graphite substrate 10 in an embodiment of the present application, since the sintering furnace in any embodiment of the first aspect is used to prepare the tantalum carbide coating on the surface of the graphite substrate 10, it also has the beneficial effects in any embodiment of the first aspect. Specifically, when sintering the graphite substrate 10, the graphite substrate 10 coated with the tantalum carbide suspension 20 can be placed in the cavity 140 first, and then the parts of the graphite substrate 10 that are not coated with the tantalum carbide suspension 20 are electrically connected to the first electrode 210 and the second electrode 220 respectively. When a voltage is applied to the first electrode 210 and the second electrode 220, the first electrode 210, the second electrode 220 and the graphite substrate 10 form a conductive circuit. Since the graphite substrate 10 is made of graphite, the graphite substrate 10 can generate heat when it is turned on, and then the graphite substrate 10 coated with the tantalum carbide suspension is sintered by utilizing the self-heating of the graphite substrate 10. The graphite substrate 10 sintered by the sintering furnace in this embodiment will not be damaged, thus ensuring the quality of subsequent crystal growth and extending the service life of the graphite substrate 10. Moreover, since there is no need to set up a heater 30, the production cost is effectively reduced, which is conducive to industrial production.

[0049] In some embodiments of the present application, the sintering furnace further includes a heat preservation chamber 300, which is disposed in the cavity 140, and a vacuum chamber 310 is disposed inside the heat preservation chamber 300, and an air inlet and an air outlet communicated with the vacuum chamber 310. The step of placing the graphite substrate 10 coated with the tantalum carbide suspension 20 in the sintering furnace includes:

[0050] S11, placing the graphite substrate 10 coated with the tantalum carbide suspension 20 in a vacuum chamber 310, and making the vacuum chamber 310 in a vacuum state.

[0051] In this embodiment, when the graphite substrate 10 is sintered, an inert gas can be introduced through the air inlet or a vacuum chamber 310 can be formed inside the insulation cavity 300 through the air outlet, thereby ensuring the gas phase partial pressure during the sintering process, which is beneficial to preparing a tantalum carbide coating on the surface of the graphite substrate 10.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0053] The various embodiments of the present application are described in a related manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0054] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A sintering furnace for sintering a tantalum carbide coating on a graphite substrate, characterized in that: The sintering furnace comprises: A furnace shell, wherein a cavity is formed inside the furnace shell, and the cavity is configured as a receiving space for sintering a graphite substrate coated with a tantalum carbide suspension; a first electrode and a second electrode, wherein one end of the first electrode contacts one side of the graphite substrate, and one end of the second electrode contacts the other side of the graphite substrate, and when a voltage is applied to the first electrode and the second electrode, the first electrode, the second electrode and the graphite substrate form a conductive loop; When sintering the graphite substrate, the graphite substrate coated with tantalum carbide suspension is first placed in the cavity, and then the portion of the graphite substrate not coated with tantalum carbide suspension is electrically connected to the first electrode and the second electrode respectively. When a voltage is applied to the first electrode and the second electrode, the first electrode, the second electrode and the graphite substrate form a conductive circuit.

2. The sintering furnace according to claim 1, characterized in that: The furnace shell includes a first furnace cover, a second furnace cover and a side furnace barrel. The first furnace cover and the second furnace cover are respectively arranged at two ends of the side furnace barrel. The first furnace cover, the second furnace cover and the side furnace barrel together form the cavity.

3. The sintering furnace according to claim 1, characterized in that: The first electrode includes a first graphite electrode and a first metal electrode, the first graphite electrode and the first metal electrode are electrically connected, and the first graphite electrode is configured to be connected to a portion of the graphite substrate.

4. The sintering furnace according to claim 1, characterized in that: The second electrode includes a second graphite electrode and a second metal electrode, the second graphite electrode and the second metal electrode are electrically connected, and the second graphite electrode is configured to be connected to a portion of the graphite substrate.

5. The sintering furnace according to claim 1, characterized in that: The sintering furnace also includes a heat preservation chamber, which is arranged in the cavity. A vacuum chamber is formed inside the heat preservation chamber. The heat preservation chamber also includes an air inlet and an air outlet connected to the vacuum chamber. The graphite substrate to be sintered is arranged in the vacuum chamber. The first electrode and the second electrode pass through the heat preservation chamber and are connected to a part of the graphite substrate.

6. A method for preparing a tantalum carbide coating on a graphite substrate surface, characterized in that: The method is implemented based on the sintering furnace according to any one of claims 1 to 5, and the steps of the method include: Placing the graphite substrate coated with the tantalum carbide suspension in the sintering furnace; Connecting the side of the graphite substrate that is not coated with the tantalum carbide suspension to the first electrode and the second electrode respectively; A voltage is applied to the first electrode and the second electrode so that the first electrode, the second electrode, and the graphite substrate form a circuit.

7. The method for preparing a tantalum carbide coating on a graphite substrate surface according to claim 6, characterized in that: The sintering furnace further comprises a heat preservation chamber, the heat preservation chamber is arranged in the cavity, a vacuum chamber is arranged inside the heat preservation chamber, and an air inlet and an air outlet communicated with the vacuum chamber, and the step of placing the graphite substrate coated with the tantalum carbide suspension in the sintering furnace comprises: The graphite substrate coated with the tantalum carbide suspension is placed in the vacuum chamber, and the vacuum chamber is placed in a vacuum state.

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