An epitaxial apparatus and a method of manufacturing the same, an epitaxial wafer and a method of manufacturing the same

Abstract

This application discloses an epitaxial apparatus and its manufacturing method, as well as an epitaxial wafer and its manufacturing method, relating to the field of semiconductor technology. The epitaxial apparatus includes a furnace cavity structure, a support portion, and a cover plate. The support portion and the cover plate are respectively disposed on opposite sides of the furnace cavity structure, and are spaced apart, with the gap between them used to place at least one substrate. The cover plate has a first surface roughness greater than 2.6 μm, and this first surface is the surface of the cover plate facing the support portion. This application reduces the number of droplet defects and triangular defects on the epitaxial wafer by roughening the cover plate of the furnace cavity structure, thereby increasing the yield of the epitaxial wafer.

Description

Technical Field

[0001] This application belongs to the field of semiconductor technology, and in particular relates to an epitaxial device and its manufacturing method, an epitaxial wafer and its manufacturing method. Background Technology

[0002] After performing preventative maintenance on the epitaxial equipment, the operator will install the new chamber cover plate and assemble it into a complete reaction chamber. Subsequently, a long coating process simulating the actual growth process will be carried out. Once the component reaches a stable process state, the chamber conditions will meet the requirements for epitaxial growth, at which point the process can be switched to the normal epitaxial growth stage.

[0003] However, in the early stages of the epitaxial growth process, derivatives, such as crystalline particles, may adhere to the cover plate. These particles are prone to detaching from the cover plate and falling onto the epitaxial wafer, which ultimately leads to a significant increase in the number of fallen particles and triangular defects after the epitaxial wafer is produced, seriously affecting the product yield of the epitaxial wafer. Summary of the Invention

[0004] This application provides an epitaxial device and its manufacturing method, an epitaxial wafer and its manufacturing method, for reducing the number of falling object defects and triangular defects on the epitaxial wafer, and improving the product yield of the epitaxial wafer.

[0005] In a first aspect, to achieve the above objectives, embodiments of this application provide an epitaxial device, which includes a furnace cavity structure, a support portion, and a cover plate.

[0006] The support and the cover are respectively located on both sides of the cavity of the furnace structure, and the support and the cover are spaced apart, with the gap between them used to place at least one substrate.

[0007] The roughness of the first surface of the cover plate is greater than 2.6 μm, and the first surface is the surface of the cover plate facing the support.

[0008] This application forms numerous tiny uneven structures on the surface of the cover plate, making its surface roughness greater than 2.6 μm, which is greater than the initial roughness of the cover plate after coating. This uneven surface of the cover plate provides attachment sites for derivatives (such as crystals and particles) generated during the epitaxial growth process, reducing the probability of derivatives falling onto the epitaxial wafer. This reduces the number of falling defects and triangular defects after the epitaxial wafer is produced, thereby improving the product yield of the epitaxial wafer.

[0009] Before the formal epitaxial growth process can begin, the equipment needs to spend a significant amount of time on a coating process to ensure that the internal environment of the furnace structure of the epitaxial equipment meets the requirements for stable operation of the epitaxial growth process.

[0010] This application achieves a cover plate surface roughness greater than 2.6 μm, resulting in an uneven surface structure that facilitates the adhesion of epitaxial growth gas. This helps the aforementioned coating process to quickly form a chamber environment suitable for epitaxial growth, effectively reducing the production costs of the coating process, including time, gas, energy, and labor.

[0011] For example, in epitaxial equipment, a cover plate without surface treatment requires nearly one-third of its lifespan to be coated to create an environment suitable for epitaxial growth. However, a cover plate with a surface roughness greater than 2.6 μm only requires less than one-eighth of its lifespan to create an environment suitable for epitaxial growth, which greatly reduces production costs, reduces production waste, improves material utilization, and increases production efficiency and economic benefits.

[0012] In some embodiments, the first surface undergoes a roughening pretreatment, and the roughness of the pretreated first surface is greater than 2.6 μm.

[0013] In some embodiments, an air inlet is provided on the cover plate for allowing epitaxial growth gas to enter the cavity of the furnace structure.

[0014] The surface roughness of the first surface after pretreatment is the average surface roughness after epitaxial growth gas is introduced and crystals adhere to the preset cover plate within a preset time period. The preset cover plate is a cover plate that has not undergone roughening treatment. The preset time period is the gas introduction time until the amount of crystals adhering to the preset cover plate falls off is less than the target value.

[0015] In some embodiments, the support includes a plurality of trays, each tray for holding a substrate; the plurality of trays are arranged circumferentially around the center line of the cover plate.

[0016] In some embodiments, the preset cover plate includes a first sub-part, a second sub-part, and a third sub-part connected in sequence, the third sub-part being disposed around the second sub-part, and the second sub-part being disposed around the first sub-part. When the preset cover plate is assembled on an extension device, the orthographic projection of the second sub-part on the support overlaps with a plurality of trays.

[0017] The roughness of the first surface after pretreatment is greater than that of the third sub-surface after the pre-set time for epitaxial growth gas to adhere and crystallize on the pre-set cover plate, and less than that of the second sub-surface.

[0018] In some embodiments, the preset cover plate includes a first sub-part, a second sub-part, and a third sub-part connected in sequence. The third sub-part is disposed around the second sub-part, and the second sub-part is disposed around the first sub-part. When the preset cover plate is assembled on an extension device, the orthographic projection of the second sub-part on the support overlaps with a plurality of trays. The cover plate includes a fourth sub-part, a fifth sub-part, and a sixth sub-part connected in sequence. The fourth, fifth, and sixth sub-parts correspond one-to-one with the first, second, and third sub-parts, respectively. The orthographic projection of the fifth sub-part on the support overlaps with a plurality of trays.

[0019] The surface roughness of the fifth sub-part facing the support is equal to the surface roughness of the second sub-part after the epitaxial growth gas adheres and crystallizes on the preset cover plate within a preset time. The surface roughness of the sixth sub-part facing the support is equal to the surface roughness of the third sub-part after the epitaxial growth gas adheres and crystallizes on the preset cover plate within a preset time.

[0020] In a first aspect, this application also provides a method for manufacturing an epitaxial device, comprising: The first surface of the cover plate of the epitaxial apparatus is roughened to a roughness greater than 2.6 μm. The cover plate is installed into the furnace cavity structure of the epitaxial apparatus, with the cover plate and the support portion of the epitaxial apparatus located on opposite sides of the cavity structure, the first surface facing the support portion. The support portion and the cover plate are spaced apart, with the gap between them used to place at least one substrate.

[0021] This application roughens the cover plate to a surface roughness greater than 2.6 μm, forming many tiny uneven structures on its surface. This provides attachment sites for the generated epitaxial particles, reducing the probability of particles falling onto the substrate. This reduces the number of falling defects and triangular defects after epitaxial wafer production, thereby improving the yield of epitaxial wafers.

[0022] By roughening the newly installed cover plate, the surface of the cover plate is made to have a surface structure similar to that after coating (e.g., the surface has a small uneven structure), so that the gas during the process growth can adhere to it. This avoids the machine spending a lot of time on coating process to make it reach the surface state required for stable process operation. It can quickly form a chamber environment that can be used for epitaxial process growth, and the production costs of time, gas, energy, and labor used in coating process are effectively reduced.

[0023] In some embodiments, roughening the first surface of the cover plate of the epitaxial device includes: A coating is applied to the substrate to form a cover plate, with the coating thickness exceeding the target thickness. The surface of the coating is then roughened to reduce its thickness to the target thickness.

[0024] In some embodiments, roughening treatment includes sandblasting and grinding.

[0025] In some embodiments, roughening the first surface of the cover plate of the epitaxial device includes: Within a preset time period, epitaxial growth gas is introduced into the cavity of the furnace structure equipped with a preset cover plate. The preset cover plate is a cover plate that has not undergone roughening treatment. The preset time period is the gas introduction time until the amount of crystals attached to the preset cover plate falling off is less than the target value.

[0026] The roughness of the surface after crystallization on the preset cover plate is measured, and the first surface is roughened according to the roughness of the surface after crystallization on the preset cover plate.

[0027] In some embodiments, roughening the first surface of the cover plate according to the roughness of the surface after crystallization on the preset cover plate includes: obtaining an average roughness of the surface after crystallization on the preset cover plate; and simultaneously roughening the first surface according to the average roughness.

[0028] In some embodiments, the support includes a plurality of trays, and the preset cover includes a first sub-section, a second sub-section, and a third sub-section connected in sequence.

[0029] The roughening treatment of the first surface based on the roughness of the surface after crystallization on the preset cover plate includes: obtaining the roughness of the surface after crystallization on the second sub-part and the third sub-part; and simultaneously roughening the first surface within the numerical range of the roughness of the surface after crystallization on the second sub-part and the third sub-part.

[0030] In some embodiments, the support includes a plurality of trays, and the preset cover includes a first sub-part, a second sub-part, and a third sub-part connected in sequence. The cover also includes a fourth sub-part, a fifth sub-part, and a sixth sub-part connected in sequence, and the orthographic projection of the fifth sub-part on the support overlaps with the plurality of trays.

[0031] The roughening treatment of the first surface based on the roughness of the crystals attached to the preset cover plate includes: obtaining the roughness of the crystals attached to the second and third sub-parts; roughening the surface of the fifth sub-part based on the roughness of the surface of the second sub-part after crystals are attached; and roughening the surface of the sixth sub-part based on the roughness of the surface of the third sub-part after crystals are attached.

[0032] Thirdly, a method for manufacturing an epitaxial wafer is also provided, the method comprising: placing a substrate in an epitaxial apparatus in any embodiment of the first aspect to perform epitaxial growth on the substrate to form an epitaxial wafer.

[0033] Fourthly, an epitaxial wafer is also provided, which is prepared using the epitaxial apparatus of any embodiment of the first aspect.

[0034] The manufacturing method of epitaxial wafers in the third aspect and the technical effects that epitaxial wafers can bring in the fourth aspect can be referred to the technical effects brought about by the structural design of epitaxial equipment in the first aspect, and will not be repeated here. Attached Figure Description

[0035] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of an epitaxial device structure provided in an embodiment of this application; Figure 2 A flowchart of an epitaxial manufacturing apparatus provided in this application embodiment; Figure 3 A cross-sectional view of a cover plate structure provided in an embodiment of this application; Figure 4 Another cross-sectional view of the cover plate structure provided in this application embodiment; Figure 5 A top view of a pre-designed cover plate structure provided in an embodiment of this application; Figure 6 This is a top view of a cover plate structure provided in an embodiment of this application. Detailed Implementation

[0036] The technical solutions in some embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application are within the scope of protection of this application.

[0037] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and encompassing, that is, "including, but not limited to".

[0038] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0039] In describing some embodiments, the term "connection" and its derivative expressions may be used. The term "connection" should be interpreted broadly; for example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. For example, in describing some embodiments, the term "connection" may be used to indicate that two or more components have direct physical or electrical contact with each other.

[0040] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0041] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0042] This document describes exemplary embodiments with reference to cross-sectional views, which are intended as idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations caused, for example, by manufacturing processes. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0043] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0044] This application provides an epitaxial device 10, such as... Figure 1 As shown, the epitaxial device 10 includes a furnace cavity structure 103, a support portion 102, and a cover plate 101.

[0045] The support portion 102 and the cover plate 101 are respectively disposed on both sides of the cavity of the furnace cavity structure 103. The support portion 102 and the cover plate 101 are spaced apart, and the gap between them is used to place at least one substrate. The roughness of the first surface of the cover plate 101 is greater than 2.6 μm. The first surface is the surface of the cover plate 101 facing the support portion 102.

[0046] The furnace cavity structure 103 provides a relatively stable and controlled environment for the entire epitaxial growth process, ensuring that the reaction takes place under suitable temperature, pressure, and other conditions. The epitaxial equipment 10 also includes an inlet 104 and an outlet. Through the inlet 104, various gases required for epitaxial growth can be accurately introduced into the furnace cavity structure 103 according to predetermined proportions and flow rates. These gases include silicon source gas, dopant gas, and carrier gas (such as hydrogen, nitrogen, etc.). The outlet is responsible for discharging the waste gas after the reaction from the furnace cavity structure 103, maintaining pressure balance and gas environment stability within the furnace cavity structure 103.

[0047] The air inlet 104, the air outlet, and the furnace cavity structure 103 work together to complete the epitaxial growth process. Gas enters the furnace cavity structure 103 through the air inlet 104 and reacts chemically with the substrate inside the furnace cavity structure 103 to achieve the growth of the epitaxial layer. The waste gas after the reaction is discharged from the furnace cavity structure 103 through the air outlet.

[0048] The support 102 and the cover plate 101 are respectively located on both sides inside the furnace cavity structure 103, and there is a certain gap between them. This gap area is where the substrate is placed. The substrate is the basic material for epitaxial growth. After the epitaxial growth process, an epitaxial layer can be grown on the surface of the substrate to finally obtain the required epitaxial wafer.

[0049] For example, cover plate 101 may include a substrate and a coating applied to the substrate. For instance, cover plate 101 may include a graphite substrate and a coating manufactured by chemical vapor deposition (CVD).

[0050] For example, the coating in cover plate 101 may include a SiC coating.

[0051] For example, the roughness of the first surface is greater than 2.6 μm by pre-processing the first surface to roughen it.

[0052] For example, before surface roughening pretreatment, the surface roughness of the cover plate 101 is approximately 2.6 μm, and it is generally smooth. For instance, the surface roughness of the SiC coating is 2.6 μm. The support portion 102 includes an inner cover layer and an outer cover layer. The surface of the cover layer is a tantalum carbide (TaC) coating, which is also relatively smooth. The TaC coating has extremely high chemical stability and can effectively resist the erosion of various corrosive substances in high-temperature and complex chemical environments.

[0053] The support 102 is typically made of high-temperature and corrosion-resistant materials, such as graphite or ceramic, to withstand the high temperatures and chemical corrosion during the epitaxial growth process.

[0054] During the epitaxial growth process, derivatives (epitaxy particles) will be generated on the cover plate 101. For example, during the epitaxial growth of a SiC substrate, 3C-SiC yellow crystals will be generated on the surface of the cover plate 101.

[0055] These crystals pose a risk of falling onto the substrate. When the amount of these crystals falling off is too large, it will result in a large number of falling object defects and triangular defects in the epitaxial wafers obtained by epitaxial growth, which will seriously affect the product yield of the epitaxial wafers.

[0056] In the epitaxial apparatus 10 provided in this application embodiment, by forming many tiny uneven structures on the surface of the cover plate 101, the surface roughness of the cover plate 101 is greater than 2.6μm, thereby providing attachment sites for the epitaxial particles generated in the epitaxial growth process, reducing the probability of particles falling onto the substrate, and thus reducing the number of falling defects and triangular defects after the epitaxial wafer is produced.

[0057] Before the formal epitaxial growth process, the machine needs to spend a lot of time on coating processes to make the internal environment of the furnace cavity structure of the epitaxial equipment 10 reach the state required for stable operation of the epitaxial growth process.

[0058] This application makes the surface roughness of the cover plate 101 greater than 2.6μm, so that the surface of the cover plate 101 has an uneven structure, which is conducive to the adhesion of epitaxial growth gas. This can help the aforementioned coating process to quickly form a chamber environment that can be used for epitaxial growth, thereby effectively reducing the production costs of time, gas, energy, and labor in the coating process.

[0059] For example, in the epitaxial apparatus 10, an untreated cover plate 101 requires nearly one-third of its lifespan for a coating process to create an environment suitable for epitaxial growth. However, a cover plate 101 with a surface roughness greater than 2.6 μm only requires less than one-eighth of its lifespan to create an environment suitable for epitaxial growth, greatly reducing production costs, reducing production waste, improving material utilization, increasing production efficiency, and improving economic benefits. In some embodiments, the furnace cavity structure 103 is provided with an air inlet 104 for allowing epitaxial growth gas to enter the cavity of the furnace cavity structure 103.

[0060] For example, the air inlet 104 is provided in a specific area of ​​the cover plate 101 (e.g. Figure 1 Located at the center of the cover plate 101, the air inlet 104 faces the support portion 102. Gas is evenly sprayed outwards through the air inlet 104, thereby forming a ring of airflow below the cover plate 101 to ensure that the gas can be evenly diffused into the space where the substrate is placed. The epitaxial growth gas includes source gas and carrier gas.

[0061] The main function of the gas inlet 104 is to serve as a channel for the epitaxial growth gas to enter the internal cavity of the furnace structure 103. In semiconductor epitaxial growth processes, gases with specific compositions and flow rates need to be introduced into the furnace cavity. For example, in the silicon carbide epitaxial growth process, gases such as silane and propane are used. After these gases enter the furnace cavity through the gas inlet 104, they undergo a chemical reaction with the substrate surface under the action of the high-temperature environment, thereby growing an epitaxial layer to form an epitaxial wafer.

[0062] In this embodiment, the surface roughness of the cover plate 101 facing the support portion 102 (i.e., the roughness of the first surface after pretreatment) can be the average surface roughness after epitaxial growth gas is introduced and crystallized on the preset cover plate 106 within a preset time period.

[0063] The preset cover plate 106 is the cover plate 101 without roughening treatment. For example, the surface roughness of the preset cover plate 106 can be less than or equal to 2.6 μm.

[0064] The preset duration is the time required for the epitaxial growth gas to be introduced until the amount of crystals falling off the preset cover plate is less than the target value.

[0065] That is, in this embodiment of the application, an epitaxial device equipped with a preset cover plate 106 is used as a test control group to obtain the roughness value required for the cover plate 101.

[0066] Before the formal epitaxial growth process, a coating process can be performed first. The conditions of the coating process can be the same as those of the epitaxial growth process. The only difference between the two is whether or not a substrate is placed. For example, the coating process can be to introduce epitaxial growth gas into the furnace cavity when no substrate is placed, so that the furnace environment can reach the state required for the stable operation of the formal epitaxial growth process under the action of the coating process.

[0067] When epitaxial growth gas is introduced into the furnace cavity during the coating process, crystals gradually adhere to the surface of the pre-set cover plate 106 facing the support portion 102. In the initial stage of the coating process, due to the relatively smooth surface of the pre-set cover plate 106, the amount of crystals that initially adhere is large, which does not meet the requirements of the formal epitaxial growth process for the amount of crystals that have fallen off. Each coating process increases the density of the crystals that adhered to the pre-set cover plate 106 in the previous coating process. Thus, after multiple coating processes over a long period of time, the density of the crystals on the pre-set cover plate 106 can be gradually increased, reducing the amount of crystals that have fallen off. When the amount of crystals that has fallen off meets the requirements of the formal epitaxial growth process, the total time for the coating process is taken as the aforementioned pre-set time, and the roughness of the crystals that adhere to the pre-set cover plate 106 at this time is taken as the roughness of the cover plate 101.

[0068] That is, in this embodiment of the application, the surface of the cover plate 101 is roughened in advance so that its roughness meets the "roughness of the crystal attached to the cover plate 106 when the amount of crystal falling off meets the requirements of the epitaxial growth process for the amount of falling off". This ensures that the cover plate 101 with this roughness can be used for epitaxial growth without multiple coating processes after being installed in the epitaxial equipment 10. In addition, during the epitaxial growth process, the amount of crystal falling off the cover plate 101 meets the requirements of epitaxial growth. That is, it ensures that the number of falling off defects and triangular defects on the epitaxial wafer attached to the epitaxial growth is small and does not affect the product performance of the epitaxial wafer.

[0069] For example, the preset cover plate 106 and cover plate 101 are identical in all parameters except for surface roughness, such as material, shape, size, and placement position in the furnace cavity structure 103. Furthermore, the process conditions set for the preset cover plate 106 and cover plate 101 are exactly the same throughout the entire epitaxial process, including but not limited to key parameters such as process temperature, gas flow rate, pressure, and time. This makes surface roughness the only variable affecting the amount of crystal drop, so that the roughness of the crystals on the preset cover plate 106 that meet the drop amount requirements can characterize the roughness of the cover plate 101 of this application.

[0070] The preset duration is a key parameter, defined as the duration from the start of epitaxial growth gas introduction until the amount of crystals falling off the preset cover plate 106 is less than the target value.

[0071] In the initial stage of epitaxial growth gas introduction, crystals gradually accumulate on the surface of the pre-set cover plate 106. However, due to factors such as an overly smooth surface, some crystals may not be able to adhere stably to the pre-set cover plate 106 and will fall off over time. The falling off of crystals attached to the surface of the cover plate 101 during epitaxial growth can lead to defects in the epitaxial wafer. The target value is a standard set based on process requirements and actual production experience. When the amount of crystal falling off is less than this target value, it can be ensured that the defects caused by falling off do not affect the performance of the epitaxial wafer, meaning that the adhesion of crystals on the surface of the pre-set cover plate 106 has reached a relatively stable state. The preset time represents the total time taken from the start of epitaxial gas introduction until the adhesion of crystals on the surface of the pre-set cover plate 106 reaches a relatively stable state.

[0072] Therefore, this application uses a coating process to simulate the environment of the formal epitaxy, wherein the conditions of the coating process and the epitaxy process are exactly the same, and a pre-set cover plate 106 is placed in the furnace cavity structure 103 during the coating process in order to characterize the amount of crystal drop during the formal epitaxy. Therefore, this application uses the crystal roughness on the pre-set cover plate 106 as a benchmark to pre-process the roughness of the cover plate 101, thereby obtaining a cover plate 101 that can achieve the requirement that the amount of crystal drop during the epitaxy process is less than the target value.

[0073] In some embodiments, the support portion 102 includes a plurality of trays 105, each tray 105 for placing a substrate, and the plurality of trays 105 are arranged circumferentially around the center line of the cover plate 101.

[0074] That is, the epitaxial equipment 10 provided in this application embodiment can be applied to the simultaneous epitaxial growth process of multiple substrates.

[0075] For example, multiple trays 105 are arranged circumferentially around the center line of the cover plate 101. From a space utilization perspective, the circumferential distribution maximizes the use of space within the furnace cavity, allowing more substrates to be placed in a limited space, thereby improving production efficiency. From a gas uniformity perspective, the circumferential distribution helps to ensure that the epitaxial growth gas is evenly distributed around the substrate. When the epitaxial growth gas is introduced into the furnace cavity, because the trays 105 are arranged circumferentially, the gas can diffuse relatively evenly to the surface of each substrate, reducing the differences in epitaxial layer growth caused by uneven gas distribution. For example, in the silicon carbide epitaxial growth process, a uniform gas distribution can ensure the consistency of the thickness, composition, and crystal quality of the silicon carbide epitaxial layer grown on each substrate.

[0076] like Figure 5 As shown, the preset cover plate 106 includes a first sub-part 1061, a second sub-part 1062 and a third sub-part 1063 connected in sequence. The third sub-part 1063 is arranged around the second sub-part 1062, and the second sub-part 1062 is arranged around the first sub-part 1061. When the preset cover plate 106 is assembled in the extension device 10, the orthographic projection of the second sub-part 1062 on the support 102 overlaps with the plurality of trays 105.

[0077] like Figure 6 As shown, the cover plate 101 includes a fourth sub-part 1011, a fifth sub-part 1012 and a sixth sub-part 1013 connected in sequence. The fourth sub-part 1011, the fifth sub-part 1012 and the sixth sub-part 1013 correspond one-to-one with the first sub-part 1061, the second sub-part 1062 and the third sub-part 1063 respectively. The orthographic projection of the fifth sub-part 1012 on the support part 102 overlaps with the plurality of trays 105.

[0078] That is, the first sub-part 1061 and the fourth sub-part 1011, the second sub-part 1062 and the fifth sub-part 1012, the third sub-part 1063 and the sixth sub-part 1013 are located at the same positions on the preset cover plate 106 and the cover plate 101, respectively. Among them, the first sub-part 1061 is located in the inner circle of the preset cover plate 106, the second sub-part 1062 is located in the middle circle of the preset cover plate 106, and the third sub-part 1063 is located in the outer circle of the preset cover plate 106. The preset cover plate 106 and the cover plate 101 are exactly the same size.

[0079] In some embodiments, the roughness of the surface of the cover plate 101 facing the support portion 102 (i.e., the roughness of the first surface after pretreatment) is greater than the roughness of the surface of the third sub-part 1063 after the epitaxial growth gas adheres and crystallizes on the preset cover plate 106 for a preset time, and less than the roughness of the surface of the second sub-part 1062.

[0080] For example, taking SiC epitaxial growth as an example, by testing the surface roughness of the crystals on the preset cover plate 106 after a preset time, the surface roughness of the first sub-part 1061, the second sub-part 1062 and the third sub-part 1063 after the crystals are attached is obtained.

[0081] Measurements revealed that the surface roughness of the first sub-part 1061 after crystallization was essentially the same as before crystallization. This indicates that during the SiC epitaxial growth process, the SiC derivatives on the first sub-part 1061 did not adhere in large quantities, and its surface morphology and roughness remained relatively stable. Visually, the color of the first sub-part 1061 remained consistent with that before crystallization, retaining the original light gray of a new part. This suggests that the sub-part was not significantly affected by process byproducts during epitaxial growth, and its surface was relatively clean.

[0082] The surface roughness of the second sub-section 1062 after crystallization is significantly different from that before crystallization. The measured roughness value reaches the upper limit of roughness, which means that the surface roughness of the second sub-section 1062 has increased significantly. In terms of color, the second sub-section 1062 changed from its original light gray to the golden yellow of SiC derivative. This indicates that process byproduct particles adhered to a large area of ​​the second sub-section 1062, causing a significant change in its surface color and roughness. When the roughness is greater than the roughness of the crystallization on the second sub-section 1062, particles formed by the coating process itself on the preset cover plate 106 will fall off, resulting in an increase in the amount of particles falling off again. That is, the surface roughness of the second sub-section 1062 after crystallization is close to the roughness threshold of the preset cover plate 106 that requires preventive maintenance (PM).

[0083] The roughness of the crystals on the third sub-section 1063 differs somewhat from that before growth, but the degree of change is less than that of the second sub-section 1062. The third sub-section 1063 is grayish-yellow in color, indicating that a small amount of SiC derivative is attached to it. By observing the number of deposits on the substrate, it can be determined that the roughness of this sub-section is within the acceptable upper limit, that is, its influence on the number of deposits on the substrate surface is within an acceptable range.

[0084] In this embodiment of the application, a suitable roughness value is selected as the roughness of the surface of the cover plate 101 facing the support portion 102. For example, the roughness value is made to be between the surface roughness of the second sub-part 1062 of the cover plate 106 after crystallization and the surface roughness value of the third sub-part 1063 after crystallization.

[0085] When the roughness is greater than the roughness value of the crystals on the second sub-section 1062, particles from the preset cover plate 106 itself will fall off, affecting the substrate and approaching the roughness threshold at which the preset cover plate 106 requires preventive maintenance (PM). When the roughness is less than the roughness of the crystals on the third sub-section 1063, the roughness does not meet the requirements for the adhesion of crystals, particles, etc., resulting in a large number of fallen objects on the substrate and making the epitaxial wafer after epitaxial growth prone to defects.

[0086] The aforementioned settings ensure that the surface of the cover plate 101 has suitable characteristics, effectively providing attachment sites for derived particles, thereby meeting the requirements of subsequent processes.

[0087] Meanwhile, the cover plate 101 has the same roughness across its entire surface, allowing for processing with uniform technology and parameters. This greatly simplifies the production process, improves production efficiency, and makes it easier to ensure the stability and consistency of product quality, thereby effectively saving production costs.

[0088] In some embodiments, the surface roughness of the fifth sub-part 1012 facing the support part 102 is equal to the surface roughness of the second sub-part 1062 after the epitaxial growth gas attaches and crystallizes on the preset cover plate 106 for a preset time (i.e., the roughness of the crystallization on the second sub-part 1062, and the same applies thereafter), and the surface roughness of the sixth sub-part 1013 facing the support part 102 is equal to the surface roughness of the third sub-part 1063 after the epitaxial growth gas attaches and crystallizes on the preset cover plate 106 for a preset time.

[0089] For example, the first sub-part 1061 and the fourth sub-part 1011, the second sub-part 1062 and the fifth sub-part 1012, the third sub-part 1063 and the sixth sub-part 1013 are located at the same positions on the preset cover plate 106 and the cover plate 101, respectively.

[0090] Based on the roughness data analysis of the above embodiments, it can be selected that the surface roughness of the fifth sub-part 1012 facing the support part 102 is equal to the roughness of the crystallization of the epitaxial growth gas on the second sub-part 1062 within a preset time, and the surface roughness of the sixth sub-part 1013 facing the support part is equal to the roughness of the crystallization of the epitaxial growth gas on the third sub-part 1063 within a preset time.

[0091] This configuration ensures that the surface of the cover plate 101 possesses suitable characteristics, more effectively providing attachment sites for derived particles, thereby meeting subsequent process requirements. Different sub-sections set their own roughness according to the pre-defined crystal roughness of their corresponding sub-sections, enabling each region of the cover plate 101 surface to form a microstructure that matches the characteristics of the derived particles. This precise matching means that when the derived particles contact the surface of the cover plate 101, they can more efficiently find suitable attachment sites. This is more conducive to reducing the impact of crystal particle shedding on the epitaxial process, and helps ensure the consistency and reliability of device performance in the epitaxial wafer.

[0092] On the other hand, this application provides a method for manufacturing an epitaxial device. Figure 2 A flowchart of a manufacturing method provided for an embodiment of this application, such as... Figure 2 As shown, the manufacturing method includes the following steps S10~S20: Step S10: Roughen the first surface of the cover plate 101 of the epitaxial device 10 so that the roughness of the first surface of the cover plate 101 is greater than 2.6 μm.

[0093] For example, the manufacturing method of step S10 includes the following steps S11 to S12: Step S11: As Figure 3 As shown, the cover plate 101 includes a substrate 1011 and a coating 1012. The coating 1012 is covered on the substrate 1011 to form the cover plate 101. The thickness of the coating 1012 needs to be greater than the target thickness so that the thickness of the coating 1012 after subsequent roughening treatment can meet the required thickness.

[0094] For example, a coating 1012 with a thickness greater than the target thickness can be formed on a substrate using chemical vapor deposition (CVD).

[0095] Step S12: As Figure 4 As shown, the surface of coating 1012 is roughened to reduce the thickness of coating 1012 to the target thickness.

[0096] For example, such as Figure 4 As shown, the surface of coating 1012 is roughened by sandblasting and grinding processes to reduce the thickness of coating 1012 to the target thickness, while making the surface roughness of coating 1012 greater than 2.6μm.

[0097] Sandblasting utilizes high-speed jets of abrasive particles, such as alumina, silicon carbide, or glass beads, to impact the surface of coating 1012. The physical impact of the abrasive removes the coating material while simultaneously creating a rough surface texture. This process allows for precise control over the reduction in coating thickness and improves surface roughness.

[0098] The polishing process uses abrasive tools such as sandpaper, grinding wheels, or diamond grinding discs to remove material from the surface of the coating 1012 through friction. This process achieves thickness reduction and surface roughening through mechanical friction and is suitable for local repairs or fine adjustments.

[0099] For example, after step S12, the manufacturing method may further include: performing water washing, air blowing and other treatment processes to remove suspended and easily detachable particles or impurities formed on the surface of the cover plate 101 due to the aforementioned process steps, thereby improving the cleanliness of the cover plate 101, facilitating the provision of a clean growth environment for subsequent epitaxial growth processes, and further improving the product yield of the epitaxial wafers formed by subsequent epitaxial growth.

[0100] Step S20: Install the cover plate 101 into the furnace cavity structure 103 of the epitaxial device 10. The cover plate 101 and the support portion 102 of the epitaxial device 10 are respectively disposed on both sides of the cavity of the furnace cavity structure 103. The first surface faces the support portion 102. The support portion 102 and the cover plate 101 are spaced apart, and the gap between them is used to place at least one substrate.

[0101] For example, the cover plate 101 and the support part 102 of the epitaxial device 10 are respectively arranged on both sides of the cavity of the furnace cavity structure 103 in order to form a relatively independent and stable spatial environment inside the furnace cavity to meet the process requirements of epitaxial growth.

[0102] During epitaxial growth, a high temperature needs to be maintained within the furnace cavity to ensure the smooth progress of the chemical reaction. The cover plate 101 has good thermal insulation properties, effectively reducing heat loss from the furnace cavity to the outside, thereby improving the temperature uniformity and stability within the furnace cavity. Simultaneously, the airflow distribution within the furnace cavity has a significant impact on the concentration of reactant gases and the temperature uniformity on the substrate surface. The shape and installation position of the cover plate 101 can guide the airflow within the furnace cavity to form a reasonable flow path, thereby balancing the airflow and ensuring that the reactant gases are evenly distributed on the substrate surface.

[0103] The support portion 102 is a key component for placing the substrate. Its design must ensure that the substrate is stable and placed horizontally to prevent it from moving or tilting during the process, which would affect the quality of the epitaxial layer.

[0104] The support 102 is typically made of high-temperature and corrosion-resistant materials, such as graphite or ceramic, to withstand the high temperatures and chemical corrosion during the epitaxial growth process.

[0105] This embodiment of the application roughens the cover plate 101 before installation, making the surface roughness of the cover plate 101 greater than 2.6μm, so that many tiny uneven structures are generated on its surface. This provides attachment sites for the epitaxial particles generated on the cover plate 101 during the epitaxial growth process after the cover plate 101 is installed, reducing the probability of particles falling onto the substrate. This reduces the number of falling object defects and triangular defects after the epitaxial wafer is produced, and improves the yield of the epitaxial wafer.

[0106] This application roughens the cover plate 101 in advance, so that the surface of the cover plate 101 has a surface structure similar to that after coating process, thereby reducing or even replacing the coating process after the new cover plate 101 is installed and before the epitaxial growth process.

[0107] For example, the rough cover plate 101 allows gases during the growth process to adhere to it, avoiding the need for the machine to spend a lot of time on the coating process to reach the surface state required for stable process operation. It can quickly form a chamber environment that can be used for epitaxial growth, and the production costs of time, gas, energy, and labor used in the coating process are effectively reduced.

[0108] In some embodiments, a short coating process is required before each formal epitaxial growth process to bring the epitaxial equipment chamber 10 into the environmental atmosphere required for formal epitaxial growth.

[0109] In some embodiments, after multiple epitaxial growths, for example, when the crystalline film layer grown on the surface of the cover plate 101 reaches 100 μm, a (preventive maintenance) PM is required to thin the cover plate 101 by grinding.

[0110] In some embodiments, step S12 includes the following steps S121 to S123: Step S121: Within a preset time period, epitaxial growth gas is introduced into the cavity of the furnace cavity structure 103, which is equipped with a preset cover plate 106.

[0111] The preset cover plate 106 is the cover plate 101 without roughening treatment, and the preset time is the time for introducing epitaxial growth gas until the amount of crystals attached to the preset cover plate 106 falling off is less than the target value.

[0112] According to the preset procedure, epitaxial growth gas is introduced into the furnace cavity structure 103, which is equipped with a preset cover plate 106. As the epitaxial growth gas is introduced, a chemical reaction occurs in the high-temperature environment inside the furnace cavity, and crystals begin to adhere to the surface of the preset cover plate.

[0113] During the gas introduction process, it is necessary to continuously monitor the amount of crystals falling off the pre-set cover plate 106. An online monitoring system, such as optical monitoring equipment, can be used to indirectly determine the crystal falling off by observing parameters such as the morphological changes of the crystals on the surface of the pre-set cover plate 106 and the intensity of reflected light. Alternatively, the furnace cavity can be opened periodically (provided it does not affect process stability, or a special observation window can be used) for visual inspection to directly observe the adhesion and falling off of crystals on the pre-set cover plate 106.

[0114] When the amount of crystals falling off the preset cover plate 106 is less than the target value, the gas is introduced for a preset duration. The target value is determined based on the quality requirements of the epitaxial wafer. For example, the amount of crystals falling off the epitaxial wafer when the surface defects are small and do not affect the quality of the epitaxial wafer is the target value.

[0115] Step S122: Measure the roughness of the crystals attached to the preset cover plate 106 (i.e., the roughness of the surface after the crystals are attached, and the same applies to subsequent steps).

[0116] For example, appropriate measurement equipment is selected based on the required accuracy of crystal roughness measurement and actual conditions. Common equipment includes atomic force microscopy (AFM), white light interferometer, and laser confocal microscopy. AFM has extremely high resolution, reaching the nanometer level, and is suitable for measuring very fine crystal surface roughness; white light interferometer has fast measurement speed and high accuracy, and can quickly scan large areas of surface; laser confocal microscopy combines high resolution and three-dimensional imaging capabilities, and can intuitively present the undulations of the crystal surface.

[0117] Step S123: Roughen the first surface of the cover plate 101 according to the roughness of the crystals attached to the preset cover plate 106.

[0118] For example, the surface roughness of the cover plate 101 is determined by combining the crystal roughness data on the preset cover plate 106 measured in step S122. The roughness range of the cover plate 101 is typically determined based on the requirements of the epitaxial growth process and the quality standards of the epitaxial wafer. For example, the first surface of the cover plate 101 can be simultaneously roughened based on the average roughness of the crystals attached to the preset cover plate 106.

[0119] By roughening the newly installed cover plate 101, the surface of the cover plate 101 is made to have a surface structure similar to that after coating process, so that the gas in the process growth can adhere to it. This avoids the machine spending a lot of time on coating process to make it reach the surface state required for stable process operation. It can quickly form a chamber environment that can be used for epitaxial process growth, and the production costs of time, gas, energy and labor used in coating process are effectively reduced.

[0120] In some embodiments, the support portion 102 includes a plurality of trays, and the preset cover plate 106 includes a first sub-part 1061, a second sub-part 1062 and a third sub-part 1063 connected in sequence.

[0121] The roughening process of the first surface of the cover plate 101 according to the roughness of the crystals attached to the preset cover plate 106 includes: obtaining the roughness of the crystals attached to the second sub-part 1062 and the third sub-part 1063, and then performing synchronous roughening process on the first surface of the cover plate 101 within the numerical range of the roughness of the crystals attached to the second sub-part 1062 and the third sub-part 1063.

[0122] For example, taking SiC epitaxial growth as an example, by testing the surface roughness of the crystals on the preset cover plate 106 that meets the conditions for epitaxial process use, the roughness of the crystals on the first sub-part 1061, the second sub-part 1062 and the third sub-part 1063 are obtained.

[0123] Measurements revealed that the roughness of the crystals on the first daughter section 1061 was essentially the same as before growth. This indicates that during the SiC epitaxial growth process, the SiC derivatives on the first daughter section 1061 did not undergo extensive growth, and its surface morphology and roughness remained relatively stable. Visually, the color of the first daughter section 1061 remained consistent with its original light gray color. This suggests that the daughter section was not significantly affected by process byproducts during epitaxial growth, and its surface was relatively clean.

[0124] The roughness of the crystals on the second sub-section 1062 differs significantly from that before growth. The measured roughness value reaches the upper limit of roughness, indicating a significant increase in the surface roughness of the second sub-section 1062. In terms of color, the second sub-section 1062 changes from its original light gray to the golden yellow of the SiC derivative. This indicates that process byproduct particles adhere extensively to the second sub-section 1062, causing a significant change in its surface color and roughness. When the roughness exceeds a certain value, particles from the preset cover plate 106 itself will fall off, approaching the roughness threshold at which preventative maintenance (PM) of the preset cover plate 106 is required.

[0125] The roughness of the crystals on the third sub-section 1063 differs somewhat from that before growth, but the degree of change is less than that of the second sub-section 1062. The third sub-section 1063 is grayish-yellow in color, indicating that a small amount of process byproducts adhere to it. By observing the number of debris on the substrate, it can be determined that the roughness of this sub-section is within the acceptable upper limit, meaning that its impact on the number of debris on the substrate surface is within acceptable limits.

[0126] Based on the above analysis, when the roughness is greater than the roughness value of the crystals on the second sub-section 1062, particles from the preset cover plate 106 itself will fall off, affecting the substrate and approaching the roughness threshold for preventive maintenance (PM) of the preset cover plate 106. When the roughness is less than the roughness of the crystals on the third sub-section 1063, the number of fallen particles on the substrate is large, and the epitaxial wafer after epitaxial growth is prone to defects. To facilitate roughening treatment of the entire surface of the cover plate 101, a suitable average roughness value can be selected. Specifically, this average roughness value should be between the roughness value of the crystals attached to the second sub-section 1062 and the roughness value of the crystals attached to the third sub-section 1063. This setting ensures that the surface of the cover plate 101 has suitable characteristics, effectively providing attachment sites for derived particles, thereby meeting the requirements of subsequent processes.

[0127] In practice, the surface of the cover plate 101 can be simultaneously roughened within the numerical range defined by the crystal roughness of the second sub-section 1062 and the third sub-section 1063. This method ensures both the consistency of the surface roughness of the cover plate 101 and fully utilizes the process requirements reflected by the crystal roughness of the second sub-section 1062 and the third sub-section 1063, enabling the roughened cover plate 101 to meet the requirements of substrate epitaxial growth.

[0128] Meanwhile, the cover plate 101 has the same roughness across its entire surface, allowing for processing with uniform technology and parameters. This greatly simplifies the production process, improves production efficiency, and makes it easier to ensure the stability and consistency of product quality, thereby effectively saving production costs.

[0129] In some embodiments, the support portion 102 includes a plurality of trays, the preset cover plate 106 includes a first sub-part 1061, a second sub-part 1062 and a third sub-part 1063 connected in sequence, and the cover plate 101 includes a fourth sub-part 1011, a fifth sub-part 1012 and a sixth sub-part 1013 connected in sequence, the orthographic projection of the fifth sub-part 1012 on the support portion 102 overlaps with the plurality of trays.

[0130] For example, the first sub-part and the fourth sub-part 1011, the second sub-part and the fifth sub-part 1012, and the third sub-part and the sixth sub-part 1013 are located at the same positions on the preset cover plate and the cover plate 101, respectively.

[0131] The roughening process of the first surface of the cover plate 101, based on the roughness of the crystals attached to the preset cover plate, includes obtaining the roughness of the crystals attached to the second sub-part 1062 and the third sub-part 1063. The surface of the fifth sub-part 1012 is roughened based on the roughness of the crystals attached to the second sub-part 1062. The surface of the sixth sub-part 1013 is roughened based on the roughness of the crystals attached to the third sub-part 1063. By setting its own roughness according to the crystal roughness of the corresponding preset sub-part, different sub-parts can form a microstructure on each region of the cover plate 101 surface that matches the characteristics of the derived particles. This precise matching means that when the derived particles contact the surface of the cover plate 101, they can more efficiently find suitable attachment sites. This is more conducive to reducing the impact of crystal particle fallout on the epitaxial process and ensuring the consistency and reliability of device performance in the epitaxial wafer.

[0132] This application also provides a method for manufacturing an epitaxial wafer, the method comprising: placing a substrate in an epitaxial apparatus in any of the embodiments of the first application and performing epitaxial growth on the substrate to form an epitaxial wafer.

[0133] For example, the epitaxial equipment with the substrate placed is heated according to a preset temperature rise curve. Once the substrate reaches the preset growth temperature, reactive gas and carrier gas are introduced into the furnace chamber according to a set gas flow rate and ratio. The reactive gas undergoes a chemical reaction on the high-temperature substrate surface, initiating the epitaxial growth process to form an epitaxial wafer.

[0134] During the manufacturing process of epitaxial wafers using pre-epitaxial equipment, the amount of crystalline particles falling off is reduced, thereby effectively reducing or even eliminating the number of defects on the epitaxial wafers. This facilitates the improvement of the product yield of epitaxial wafers. Furthermore, during the manufacturing process of epitaxial wafers, there is no need to spend a lot of time on coating processes, which can effectively shorten the preparation time of the epitaxial wafer preparation process and improve the output efficiency of epitaxial wafers.

[0135] This application also provides an epitaxial wafer, which is prepared using the epitaxial apparatus described in any of the foregoing embodiments.

[0136] The epitaxial wafers prepared using the aforementioned epitaxial equipment have fewer surface defects, thus ensuring the product yield of the epitaxial wafers.

[0137] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An epitaxial device, characterized in that, include: Furnace cavity structure; A support and a cover plate are respectively disposed on both sides of the cavity of the furnace cavity structure; the support and the cover plate are spaced apart, and the gap between them is used to place at least one substrate; The roughness of the first surface of the cover plate is greater than 2.6 μm, and the first surface is the surface of the cover plate facing the support.

2. The epitaxial device according to claim 1, wherein the first surface is subjected to a roughening pretreatment, and the roughness of the first surface after the pretreatment is greater than 2.6 μm.

3. The epitaxial device according to claim 2, characterized in that, The furnace cavity structure is provided with an air inlet, which is used to allow epitaxial growth gas to enter the cavity of the furnace cavity structure. The roughness of the first surface after pretreatment is the average surface roughness after the epitaxial growth gas is introduced and crystallized on the preset cover plate within a preset time period. The preset cover plate is a cover plate that has not undergone roughening treatment; the preset duration is the duration for which the epitaxial growth gas is introduced until the amount of crystals attached to the preset cover plate falling off is less than a target value.

4. The epitaxial device according to claim 3, characterized in that, The support includes multiple trays, each tray for placing one of the substrates; the multiple trays are arranged circumferentially around the center line of the cover plate.

5. The epitaxial device according to claim 4, characterized in that, The preset cover plate includes a first sub-part, a second sub-part, and a third sub-part connected in sequence. The third sub-part is arranged around the second sub-part, and the second sub-part is arranged around the first sub-part. When the preset cover plate is assembled on the extension device, the orthographic projection of the second sub-part on the support overlaps with the plurality of trays. The roughness of the first surface after pretreatment is greater than the roughness of the third sub-surface after the epitaxial growth gas adheres and crystallizes on the preset cover plate within the preset time period, and less than the roughness of the second sub-surface.

6. The epitaxial device according to claim 4, characterized in that, The preset cover plate includes a first sub-part, a second sub-part, and a third sub-part connected in sequence. The third sub-part is arranged around the second sub-part, and the second sub-part is arranged around the first sub-part. When the preset cover plate is assembled on the extension device, the orthographic projection of the second sub-part on the support overlaps with the plurality of trays. The cover plate includes a fourth sub-section, a fifth sub-section, and a sixth sub-section connected in sequence. The fourth sub-section, the fifth sub-section, and the sixth sub-section correspond one-to-one with the first sub-section, the second sub-section, and the third sub-section, respectively. The orthographic projection of the fifth sub-section on the support overlaps with the plurality of trays. The surface roughness of the fifth sub-part facing the support is equal to the surface roughness of the second sub-part after the epitaxial growth gas adheres and crystallizes on the preset cover plate within the preset time period; the surface roughness of the sixth sub-part facing the support is equal to the surface roughness of the third sub-part after the epitaxial growth gas adheres and crystallizes on the preset cover plate within the preset time period.

7. A method for manufacturing an epitaxial device, characterized in that, include: The first surface of the cover plate of the epitaxial device is roughened; This results in the roughness of the first surface being greater than 2.6 μm; The cover plate is installed into the furnace cavity structure of the epitaxial device; the cover plate and the support portion of the epitaxial device are located on both sides of the cavity of the furnace cavity structure, with the first surface facing the support portion; the support portion and the cover plate are spaced apart, and the gap between them is used to place at least one substrate.

8. The manufacturing method according to claim 7, characterized in that, The roughening treatment of the first surface of the cover plate of the epitaxial device includes: A coating is applied to a substrate to form the cover plate; the thickness of the coating is greater than the target thickness. The surface of the coating is roughened to reduce the thickness of the coating to the target thickness.

9. The manufacturing method according to claim 7, characterized in that, The roughening treatment includes sandblasting and grinding processes.

10. The manufacturing method according to claim 7, characterized in that, The roughening treatment of the first surface of the cover plate of the epitaxial device includes: Within a preset time period, epitaxial growth gas is introduced into the cavity of the furnace cavity structure equipped with a preset cover plate; the preset cover plate is a cover plate that has not undergone roughening treatment; the preset time period is the gas introduction time until the amount of crystals attached to the preset cover plate falling off is less than a target value. Measure the surface roughness of the pre-set cover plate after crystallization; The first surface is roughened according to the roughness of the surface after crystallization on the preset cover plate.

11. The manufacturing method according to claim 10, characterized in that, The roughening treatment of the first surface based on the roughness of the surface after crystallization on the preset cover plate includes: The average surface roughness of the pre-set cover plate after crystallization is obtained; The first surface is simultaneously roughened based on the average value.

12. The manufacturing method according to claim 10, characterized in that, The support portion includes multiple trays, and the preset cover includes a first sub-part, a second sub-part, and a third sub-part connected in sequence; The roughening treatment of the first surface based on the roughness of the surface after crystallization on the preset cover plate includes: The surface roughness of the second sub-part and the third sub-part after crystallization is obtained; Within the numerical range of the surface roughness of the crystallized surfaces attached to the second and third sub-parts, the first surface is simultaneously roughened.

13. The manufacturing method according to claim 10, characterized in that, The support portion includes multiple trays, and the preset cover plate includes a first sub-part, a second sub-part, and a third sub-part connected in sequence. The cover plate includes a fourth sub-part, a fifth sub-part, and a sixth sub-part connected in sequence. The orthographic projection of the fifth sub-part on the support portion overlaps with the multiple trays. The roughening treatment of the first surface based on the roughness of the surface after crystallization on the preset cover plate includes: The surface roughness of the second sub-part and the third sub-part after crystallization is obtained; The surface of the fifth sub-part is roughened according to the surface roughness of the second sub-part after crystallization; The surface of the sixth sub-part is roughened according to the surface roughness of the crystallized surface attached to the third sub-part.

14. A method for manufacturing an epitaxial wafer, characterized in that, include: The substrate is placed in the epitaxial apparatus as described in any one of claims 1 to 6 to perform epitaxial growth on the substrate, thereby forming an epitaxial wafer.

15. An epitaxial wafer, characterized in that, It is prepared using the epitaxial apparatus as described in any one of claims 1 to 6.

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