Epitaxial furnace graphite piece, pretreatment method thereof and preparation method of epitaxial wafer
By forming a dense initial silicon carbide coating on the cover plate of the epitaxial furnace cavity, the problem of particle falling off caused by the smooth surface of the cavity cover plate in the epitaxial process is solved, thereby improving the quality of epitaxial wafers and production efficiency.
Patent Information
- Application Number
- CN202610286182.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-10
- Publication Date
- 2026-05-15
AI Technical Summary
After the replacement of the cover plate of the epitaxial furnace cavity in the epitaxial process, the surface is too smooth, which makes it easy for particles to fall off and affect the quality of the epitaxial wafer. In addition, the increased roughness of the existing surface makes the operation time longer and affects production efficiency.
After replacing the cavity cover plate, the temperature and growth rate are controlled by pretreatment correction parameters to form a dense initial silicon carbide coating to increase surface roughness and reduce particle adhesion. The initial silicon carbide coating is epitaxially grown on the inner surface of the cover plate using carbon source and silicon source gas.
It effectively shortens pretreatment time, reduces production costs, improves material utilization and production efficiency, and enhances the quality of epitaxial wafers.
Smart Images
Figure CN122039210A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to an epitaxial furnace graphite component and its pretreatment method, and a method for preparing epitaxial wafers. Background Technology
[0002] Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) made of third-generation wide-bandgap semiconductors such as silicon carbide or gallium nitride have the characteristics of large critical breakdown electric field strength, high thermal conductivity, large bandgap width and high electron saturation drift velocity, making third-generation wide-bandgap semiconductor materials such as silicon carbide or gallium nitride a research hotspot for power semiconductor devices.
[0003] Epitaxy is a crucial process in the fabrication of power semiconductor devices. However, after replacing the graphite components in the epitaxial furnace, the surface of the furnace becomes too smooth, especially the top cavity cover. During epitaxy, particles adhering to the cavity cover are prone to falling onto the wafer surface, affecting the quality of the epitaxial wafer. Furthermore, increasing the surface roughness of the graphite components is time-consuming, impacting production efficiency. Summary of the Invention
[0004] This application provides an epitaxial furnace graphite part and its pretreatment method, as well as a method for preparing epitaxial wafers, in order to improve the quality of epitaxial wafers, reduce production costs, and increase production efficiency.
[0005] Firstly, a pretreatment method for epitaxial furnace graphite parts is provided, including: Replace the cover plate of the cavity to be processed with a new one and seal the epitaxial furnace; wherein the cover plate of the cavity to be processed includes a graphite substrate; Obtain pretreatment correction parameters, heat the epitaxial furnace according to the pretreatment correction parameters, and introduce reaction source gas into the epitaxial furnace to epitaxially form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed, thereby obtaining the chamber cover plate; wherein, the pretreatment correction parameters include a preset correction temperature and a preset correction growth rate, and the reaction source gas includes a carbon source gas and a silicon source gas.
[0006] Optionally, the step of heating the epitaxial furnace according to the pretreatment correction parameters and introducing a reaction source gas into the epitaxial furnace to epitaxially form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed includes: The epitaxial furnace is heated to the preset correction temperature and held. On the inner surface of the cavity cover plate to be processed, the initial silicon carbide coating with a preset thickness is epitaxially grown using the reaction source gas at the preset modified growth rate.
[0007] Optionally, the preset correction temperature ranges from 1550 to 1700°C, and the preset correction growth rate is less than 2 to 5 μm / h.
[0008] Optionally, the preset thickness of the initial silicon carbide coating ranges from 10 to 30 μm.
[0009] Optionally, the surface roughness of the initial silicon carbide coating includes an inner ring surface roughness, a middle ring surface roughness, and an outer ring surface roughness; The surface roughness of the inner ring is less than that of the middle ring, and the surface roughness of the inner ring is less than that of the outer ring. The surface roughness of the middle ring is greater than or equal to that of the outer ring.
[0010] Optionally, replacing the cover plate of the cavity to be treated includes: Replace the inner surface of the cavity cover with a new cover plate that has a silicon carbide roughening film.
[0011] In a second aspect, an epitaxial furnace graphite part is provided, which is obtained by the pretreatment method for epitaxial furnace graphite parts described in any embodiment of the first aspect.
[0012] Thirdly, a method for preparing an epitaxial wafer is provided, including a pretreatment method for an epitaxial furnace graphite part as described in any embodiment of the first aspect, to pretreat a newly replaced cavity cover plate to be processed, thereby obtaining the cavity cover plate.
[0013] Optionally, the method for preparing the epitaxial wafer further includes: A wafer is placed in the epitaxial furnace, and the epitaxial furnace is sealed using the cavity cover plate; The epitaxial furnace is heated, and a reaction source gas is released into the epitaxial furnace to grow an epitaxial layer on the surface of the wafer.
[0014] Optionally, the method for preparing the epitaxial wafer further includes: The cavity cover plate of the epitaxial furnace shall be replaced periodically; The pretreatment method for the graphite part of the epitaxial furnace as described in any embodiment of the first aspect is used to pretreat the new cavity cover plate to be processed, so as to epitaxially form an epitaxial layer on the surface of the wafer.
[0015] The pretreatment method for graphite parts in an epitaxial furnace provided in this application involves sealing the epitaxial furnace after replacing the cover plate of the chamber to be treated. Using the obtained pretreatment correction parameters, the sealed epitaxial furnace is heated, and reaction source gases such as carbon and silicon sources required for the silicon carbide reaction are introduced into the furnace. This pretreatment of the cover plate of the chamber to be treated allows for the epitaxial growth of an initial silicon carbide coating on the inner surface of the cover plate. Compared to the thicker coatings grown in related technologies, this application modifies and adjusts the epitaxial process parameters used in the pretreatment in related technologies to obtain the pretreatment correction parameters. Heating the epitaxial furnace and releasing the corresponding reaction source gases according to the pretreatment correction parameters allows for the growth of a denser initial silicon carbide coating on the inner surface of the cover plate. Because the initial silicon carbide coating has better density, a thinner initial silicon carbide coating can be grown to achieve the surface condition required for stable operation of the epitaxial process. This can effectively shorten the time spent in the pretreatment process, greatly reduce production costs, improve material utilization, and enhance production and economic benefits.
[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic flowchart of a pretreatment method for graphite parts in an epitaxial furnace according to an embodiment of this application; Figure 2 This is a schematic diagram of the specific process of step S120 in a pretreatment method for graphite parts in an epitaxial furnace according to an embodiment of this application. Detailed Implementation
[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0021] This application provides a pretreatment method for graphite parts in an epitaxial furnace. Figure 1 This is a schematic flowchart illustrating a pretreatment method for epitaxial furnace graphite parts provided in an embodiment of this application. Figure 1 As shown, the pretreatment method for the epitaxial furnace graphite part specifically includes the following steps: S110. Replace the new cover plate of the cavity to be treated and seal the epitaxial furnace; wherein, the cover plate of the cavity to be treated includes a graphite substrate.
[0022] Specifically, graphite components such as the cavity cover of the epitaxial furnace are consumables in the epitaxial process and have a limited service life. Therefore, it is necessary to replace the cavity cover with a new one before it reaches the end of its service life. New cavity covers are mostly made of graphite substrate, or a combination of graphite substrate and silicon carbide coating obtained by chemical vapor deposition, with a relatively smooth surface roughness of approximately 2.6 μm. The cavity cover is placed on top of the epitaxial furnace to seal the interior cavity. The epitaxial furnace is a multi-wafer epitaxial furnace capable of accommodating multiple wafers for simultaneous epitaxial processing.
[0023] S120. Obtain pretreatment correction parameters, heat the epitaxial furnace according to the pretreatment correction parameters, and introduce reaction source gas into the epitaxial furnace to form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed, thereby obtaining the chamber cover plate; wherein, the pretreatment correction parameters include a preset correction temperature and a preset correction growth rate, and the reaction source gas includes carbon source gas and silicon source gas.
[0024] Specifically, the pretreatment correction parameters are the epitaxial process parameters for pretreatment that increase the roughness of the epitaxial furnace chamber cover. These parameters are modified from the pretreatment epitaxial process parameters of related technologies, including preset correction temperature and preset correction growth rate. For newly replaced graphite parts of the epitaxial furnace chamber cover, the excessively smooth surface prevents the cover from providing effective adhesion sites for silicon carbide particles with 3C structures generated during epitaxy in the initial stages of use. This causes silicon carbide particles to fall onto the wafer surface, resulting in a surge in the number of fallen particles on the epitaxial wafer surface and affecting wafer quality. However, to increase the surface roughness of the newly replaced epitaxial furnace chamber cover and improve the adhesion of particles to the cover surface during epitaxy, related technologies replace the entire set of graphite parts in the epitaxial furnace after preventive maintenance (PM) of multiple epitaxial furnaces, forming a complete epitaxial reaction chamber. Because the surface of the epitaxial furnace cavity cover plate is too smooth, the specific surface area of the surface coating is small. Therefore, the machine needs to spend a lot of time performing long-term high-temperature baking and simulating the coating process in the growth process. Furthermore, the coating roughness obtained by the coating process parameters used in related technologies is too large, requiring the growth of a thicker coating of more than 100μm to ensure that the epitaxial furnace cavity cover plate reaches the surface state required for stable process operation and improve the quality of the epitaxial wafer.
[0025] In related technologies, growing thicker coatings is time-consuming, consuming a significant portion of the limited lifespan of the epitaxial furnace cavity cover. In this embodiment, by modifying and adjusting the growth parameters of the coating growth process—specifically, growing the coating according to a preset modified temperature and growth rate—and by introducing carbon and silicon source gases into the epitaxial furnace, a denser silicon carbide coating with appropriately reduced surface roughness—the initial silicon carbide coating—can be grown. This initial silicon carbide coating is formed on the inner surface of the cavity cover before the formal epitaxial wafer fabrication process. It increases the surface roughness of the new cavity cover, improving the adhesion of silicon carbide particles to the cover surface, thus reducing particles falling onto the wafer surface during the epitaxial process and improving wafer quality. Furthermore, due to the increased density of the silicon carbide coating, a thinner coating can achieve the surface condition required for stable process operation. This approach ensures that the pretreated cavity cover plate meets the requirements for stable epitaxial growth process operation and improves the quality of grown epitaxial wafers, while significantly reducing production costs, increasing material utilization, and enhancing production and economic benefits.
[0026] The pretreatment method for graphite parts in an epitaxial furnace provided in this application involves sealing the epitaxial furnace after replacing the cover plate of the chamber to be treated. Using the obtained pretreatment correction parameters, the sealed epitaxial furnace is heated, and reaction source gases such as carbon and silicon sources required for the silicon carbide reaction are introduced into the furnace. This pretreatment of the cover plate of the chamber to be treated allows for the epitaxial growth of an initial silicon carbide coating on the inner surface of the cover plate. Compared to the thicker coatings grown in related technologies, this application modifies and adjusts the epitaxial process parameters used in the pretreatment in related technologies to obtain the pretreatment correction parameters. Heating the epitaxial furnace and releasing the corresponding reaction source gases according to the pretreatment correction parameters allows for the growth of a denser initial silicon carbide coating on the inner surface of the cover plate. Because the initial silicon carbide coating has better density, a thinner initial silicon carbide coating can be grown to achieve the surface condition required for stable operation of the epitaxial process. This can effectively shorten the time spent in the pretreatment process, greatly reduce production costs, improve material utilization, and enhance production and economic benefits.
[0027] Based on the above embodiments, Figure 2 This is a schematic flowchart illustrating step S120 of a pretreatment method for graphite parts in an epitaxial furnace provided in an embodiment of this application. See also... Figure 2 Optionally, step S120, which involves heating the epitaxial furnace according to the pretreatment correction parameters and releasing silicon source gas into the epitaxial furnace to epitaxially form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed, specifically includes the following steps: S121. Heat the epitaxial furnace to the preset correction temperature and maintain it.
[0028] Specifically, during the pretreatment process, the epitaxial furnace is heated at a certain heating rate until the temperature inside the furnace reaches a preset correction temperature. The temperature inside the furnace is then maintained at the preset correction temperature to facilitate epitaxial growth during the pretreatment process. For example, the preset correction temperature ranges from 1550 to 1700°C. Generally, in related technologies, the process temperature for increasing the surface roughness of the new chamber cover plate during epitaxial growth is mostly 1500°C. Compared to related technologies, this embodiment appropriately increases the epitaxial growth temperature, setting the preset correction temperature in the range of 1550 to 1700°C. This is beneficial for obtaining an initial silicon carbide coating with a smaller surface roughness, and the initial silicon carbide coating has a denser texture, providing effective adhesion sites for the silicon carbide particles with 3C structures generated in the subsequent epitaxial wafer growth process, resulting in fewer particles falling onto the wafer surface.
[0029] S122. On the inner surface of the cavity cover plate to be processed, an initial silicon carbide coating with a preset thickness is epitaxially grown using a reaction source gas at a preset modified growth rate.
[0030] Specifically, after the temperature inside the epitaxial furnace reaches and is maintained at a preset correction temperature, reaction source gases such as carbon and silicon sources required for the silicon carbide reaction are introduced into the epitaxial furnace, and epitaxial growth is performed according to a preset correction growth rate, thereby growing an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed. For example, the preset correction growth rate is less than 2 to 5 μm / h. Generally, in related technologies, the growth rate of the epitaxial growth process to increase the surface roughness of the new chamber cover plate to be processed is mostly above 10 μm / h. Compared with related technologies, the embodiments of this application appropriately reduce the growth rate, setting the preset growth rate in the range of 2 to 5 μm / h, which is beneficial for obtaining an initial silicon carbide coating with lower surface roughness and a denser texture. Regarding the preset correction temperature and preset correction growth rate, setting the preset correction temperature too low or the preset correction growth rate too high may result in a rougher and more porous initial silicon carbide coating. This can easily lead to the shedding of particles during growth, making it difficult to reduce particle shedding from the epitaxial wafer surface during the initial use after replacing the chamber cover, thus affecting the quality of the epitaxial wafer. Setting the preset correction temperature too high will increase the etching of the chamber cover by the reactive gases during the initial silicon carbide coating growth process, potentially causing the coating on the replaced graphite part to peel off, even affecting the lifespan of the graphite part and increasing production costs. Setting the preset correction growth rate too slow will not effectively reduce the surface roughness of the initial silicon carbide coating and will increase the pretreatment time due to the slower growth rate, thereby increasing production costs.
[0031] Based on the above embodiments, optionally, the preset thickness of the initial silicon carbide coating is in the range of 10 ~ 30 μm.
[0032] Specifically, the surface pretreatment of the chamber cover plate is performed using adjusted pretreatment correction parameters. Since the initial silicon carbide coating is denser, appropriately reducing the initial silicon carbide coating thickness can achieve the surface condition required for stable operation of the epitaxial process. For example, the preset thickness of the initial silicon carbide coating can be in the range of 10 to 30 μm. In contrast, the thickness of the silicon carbide coating grown in related technologies exceeds 100 μm. Therefore, the pretreatment method for epitaxial furnace graphite parts provided in this application requires only one-third the time of related technologies. Thus, the pretreatment method for epitaxial furnace graphite parts provided in this application can effectively improve production costs, production efficiency, and economic benefits.
[0033] Based on the above embodiments, optionally, the surface roughness of the initial silicon carbide coating includes the inner ring surface roughness, the middle ring surface roughness, and the outer ring surface roughness; The surface roughness of the inner ring is less than that of the middle ring, and the surface roughness of the inner ring is less than that of the outer ring. The surface roughness of the middle ring is greater than or equal to that of the outer ring.
[0034] Specifically, for the cavity cover plate that has achieved stable operation of the epitaxial process after epitaxial growth of silicon carbide coating using relevant technologies, the surface roughness of the inner, middle, and outer rings of the coating can be measured to obtain the average surface roughness values. The average surface roughness of the inner ring is basically the same as that before growth, indicating that a large amount of 3C-structured silicon carbide derivatives were not grown in the inner ring of the cavity cover plate. The average surface roughness of the middle ring is significantly greater than that before growth, and this is visible to the naked eye through color changes on the middle ring surface, indicating that silicon carbide-derived particles, a byproduct of the epitaxial process, adhere to a large area in the middle ring region. The average surface roughness of the outer ring is slightly larger than before growth, indicating that a small amount of silicon carbide-derived particles, a byproduct of the epitaxial process, adhere to the outer ring region. However, the excessively large surface roughness of the middle ring region after growth in related technologies results in a relatively loose coating texture, which is detrimental to improving the quality of the epitaxial wafer.
[0035] The initial silicon carbide coating grown using the pretreatment method for graphite parts in the epitaxial furnace provided in this application has a surface roughness in the middle ring region that is greater than or equal to that of the outer ring, meaning the surface roughness of the middle ring is close to that of the outer ring. Compared to related technologies, this effectively reduces the surface roughness of the middle ring, thereby providing effective attachment sites for byproduct-derived particles. This effectively reduces the amount of byproduct-derived particles adhering to the cavity cover plate surface during growth that fall onto the wafer surface, thus improving the quality of the epitaxial wafer.
[0036] Based on the above embodiments, optionally, the replacement of the new cover plate of the cavity to be processed in step S110 further includes the following steps: Replace the inner surface of the cavity cover with a new cover plate that has a silicon carbide roughening film.
[0037] Specifically, for newly replaced chamber cover plates, to achieve the surface condition required for stable operation of the epitaxial process, in addition to pre-epitaxially treating the inner surface of the chamber cover plate according to pre-treatment correction parameters to generate an initial silicon carbide coating, as provided in any of the above embodiments, whose dense texture and thin thickness can effectively improve the quality of the epitaxial wafer and production efficiency, it is also possible to directly replace the chamber cover plate with a silicon carbide roughening film layer on its inner surface as a new graphite part. Using a chamber cover plate with a silicon carbide roughening film layer, a thinner initial silicon carbide film layer can be grown to meet the requirements for stable operation of the epitaxial process, thereby further reducing the time spent on pre-treatment, which is conducive to further reducing production costs and improving production efficiency and economic benefits.
[0038] This application also provides an epitaxial furnace graphite part. This epitaxial furnace graphite part is obtained by the pretreatment method for epitaxial furnace graphite parts provided in any of the above embodiments, and has similar beneficial effects as the pretreatment method for epitaxial furnace graphite parts. The surface state of the epitaxial furnace graphite part obtained by such pretreatment can meet the requirements for stable operation of the epitaxial process, effectively reducing the amount of derivative particles generated during subsequent epitaxial wafer preparation that fall onto the wafer surface, thus improving the quality of the epitaxial wafer. Furthermore, using pretreatment correction parameters for pretreatment can effectively shorten the pretreatment time, effectively reduce production costs, and provide production efficiency and economic benefits.
[0039] This application also provides a method for preparing an epitaxial wafer. This method includes the pretreatment method for the graphite components of the epitaxial furnace provided in any of the above embodiments, to pretreatment a newly replaced cavity cover plate to be processed, thereby obtaining the cavity cover plate. By using this method to prepare the epitaxial wafer, when the cavity cover plate reaches its service life, a new cavity cover plate or other graphite components can be replaced. Pretreatment using pretreatment correction parameters forms a dense and thin initial silicon carbide coating on the inner surface of the cavity cover plate, effectively reducing particles falling onto the wafer surface during the epitaxial process, improving the quality of the epitaxial wafer, and reducing production costs, thus improving production efficiency and economic benefits.
[0040] Based on the above embodiments, the method for preparing the epitaxial wafer may optionally include the following steps: Wafers are placed in the epitaxial furnace, and the furnace is sealed with a cavity cover plate.
[0041] Specifically, after pre-treating the newly replaced cavity cover to achieve the surface condition required for stable operation of the epitaxial process, the wafer to be prepared is placed on the support stage in the inner cavity of the epitaxial furnace and fixed. Then, the epitaxial furnace is sealed with the pre-treated cavity cover.
[0042] The epitaxial furnace is heated, and the reaction source gas is released into the epitaxial furnace to grow an epitaxial layer on the surface of the wafer.
[0043] Specifically, after sealing is completed, heating of the epitaxial furnace begins, raising the temperature inside the furnace until it reaches the reaction temperature required for the epitaxial reaction. At the same time, carbon source, silicon source, and other reaction source gases required for the reaction are injected into the epitaxial furnace, thereby achieving epitaxial growth on the wafer surface to obtain an epitaxial layer, and then obtaining an epitaxial wafer.
[0044] Based on the above embodiments, the method for preparing the epitaxial wafer may optionally include the following steps: The cavity cover plate of the epitaxial furnace should be replaced regularly.
[0045] Specifically, since the graphite components in the epitaxial furnace have a certain service life, the furnace cavity cover plate needs to be replaced regularly and in a timely manner before the graphite components reach the end of their service life to ensure the stable operation of the epitaxial process.
[0046] Using the pretreatment method for the graphite part of the epitaxial furnace provided in any of the above embodiments, the new cavity cover plate to be processed is pretreated to form an epitaxial layer on the surface of the wafer.
[0047] Specifically, the new cavity cover plate to be processed is pretreated using the pretreatment method of the epitaxial furnace graphite part provided in any of the above embodiments, so as to ensure that the subsequent epitaxial process can operate stably, realize the epitaxial growth of the epitaxial layer on the wafer surface, and effectively reduce the number of derivative particles falling on the wafer surface, which is beneficial to improving the quality of the prepared epitaxial wafer.
[0048] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A pretreatment method for epitaxial furnace graphite parts, characterized in that, include: Replace the cover plate of the cavity to be processed with a new one and seal the epitaxial furnace; wherein the cover plate of the cavity to be processed includes a graphite substrate; Obtain pretreatment correction parameters, heat the epitaxial furnace according to the pretreatment correction parameters, and introduce reaction source gas into the epitaxial furnace to epitaxially form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed, thereby obtaining the chamber cover plate; wherein, the pretreatment correction parameters include a preset correction temperature and a preset correction growth rate, and the reaction source gas includes a carbon source gas and a silicon source gas.
2. The pretreatment method for epitaxial furnace graphite parts according to claim 1, characterized in that, The step of heating the epitaxial furnace according to the pretreatment correction parameters and introducing a reaction source gas into the epitaxial furnace to epitaxially form an initial silicon carbide coating on the inner surface of the chamber cover plate to be processed includes: The epitaxial furnace is heated to the preset correction temperature and held. On the inner surface of the cavity cover plate to be processed, the initial silicon carbide coating with a preset thickness is epitaxially grown using the reaction source gas at the preset modified growth rate.
3. The pretreatment method for epitaxial furnace graphite parts according to claim 2, characterized in that, The preset correction temperature ranges from 1550 to 1700°C, and the preset correction growth rate is less than 2 to 5 μm / h.
4. The pretreatment method for epitaxial furnace graphite parts according to claim 3, characterized in that, The preset thickness of the initial silicon carbide coating is in the range of 10 ~ 30 μm.
5. The pretreatment method for epitaxial furnace graphite parts according to claim 3, characterized in that, The surface roughness of the initial silicon carbide coating includes the inner ring surface roughness, the middle ring surface roughness, and the outer ring surface roughness; The surface roughness of the inner ring is less than that of the middle ring, and the surface roughness of the inner ring is less than that of the outer ring. The surface roughness of the middle ring is greater than or equal to that of the outer ring.
6. The pretreatment method for epitaxial furnace graphite parts according to claim 1, characterized in that, The replacement of the new cover plate of the cavity to be processed includes: Replace the inner surface of the cavity cover with a new cover plate that has a silicon carbide roughening film.
7. An epitaxial furnace graphite component, characterized in that, It is obtained by the pretreatment method of epitaxial furnace graphite parts as described in any one of claims 1-6.
8. A method for preparing an epitaxial wafer, characterized in that, The method includes a pretreatment method for epitaxial furnace graphite parts as described in any one of claims 1-6, for pretreatment of newly replaced cavity cover plates to be treated, to obtain cavity cover plates.
9. The method for preparing an epitaxial wafer according to claim 8, characterized in that, Also includes: A wafer is placed in the epitaxial furnace, and the epitaxial furnace is sealed using the cavity cover plate; The epitaxial furnace is heated, and a reaction source gas is released into the epitaxial furnace to grow an epitaxial layer on the surface of the wafer.
10. The method for preparing an epitaxial wafer according to claim 9, characterized in that, Also includes: The cavity cover plate of the epitaxial furnace shall be replaced periodically; The pretreatment method for the graphite part of the epitaxial furnace as described in any one of claims 1-6 is used to pretreat the new cavity cover plate to be processed, so as to epitaxially form an epitaxial layer on the surface of the wafer.