27 results about "Vapour phase epitaxy" patented technology

The invention provides a method for growing a (310) oriented beta-Ga2O3 single crystal thick film on a sapphire substrate. The method comprises the following steps: cleaning the sapphire substrate and then carrying out annealing treatment; and with hydrogen chloride gas, gallium metal and oxygen as reaction sources, epitaxially growing a (310) oriented beta-Ga2O3 single crystal thick film on the treated sapphire substrate by using a hydride vapor phase epitaxy method. According to the method for growing the (310) oriented beta-Ga2O3 single crystal thick film on the sapphire substrate, the process is simple, operation is easy, controllability is high, the obtained (310) oriented beta-Ga2O3 single crystal thick film is smooth in surface, compact and uniform in thickness, the crystallinity of the single crystal film layer is high, and the growth requirement of a single crystal epitaxial film layer of tens of micrometers can be met; in addition, the method provided by the invention can realize large-batch and large-scale production of the (310) oriented beta-Ga2O3 single crystal thick film, and meets the device preparation requirements.

The invention discloses a space-time modulation hydride vapor phase epitaxy reaction chamber, equipment and a method. Wherein the reaction chamber comprises a reaction chamber which is provided with a water cooling side wall and is limited by a flange to form a cavity, and the interior of the cavity is divided into an upper part, a middle part and a lower part; the metal source reaction boat assembly is positioned at the upper half part of the reaction chamber cavity; the space-time modulation reaction growth device is positioned in the middle of the reaction chamber cavity; the heating device and the tail gas collecting device are positioned at the lower half part of the reaction chamber cavity; and the central gas circuit device is positioned at the axis position of the cavity of the reaction chamber and is connected with the metal source reaction boat assembly at the upper half part of the cavity and the space-time modulation reaction growth device in the middle of the cavity. According to the invention, the growth time is controlled through the combination of time modulation and space modulation, so that the thickness of the material thin layer is accurately controlled, the flexibility of growth program setting is improved, the rapid epitaxial growth of the ultra-thin layer and ultra-thick layer material stacking structure is realized, and the low-cost epitaxial growth requirement of a semiconductor device with a complex structure is met.

The utility model discloses vapor phase epitaxy equipment which comprises an epitaxy furnace body, an epitaxy cavity is arranged in the epitaxy furnace body, a raw material chamber, a gas spray head and at least one tray are arranged in the epitaxy cavity, a raw material boat is arranged in the raw material chamber, the tray is arranged below the gas spray head, and the gas spray head is arranged on the tray. The tray is used for bearing a wafer for epitaxial growth, the raw material boat is communicated with the gas spraying head, the gas spraying head is used for spraying reaction gas to the wafer so as to grow a crystal epitaxial layer on the wafer, and the top of the epitaxial furnace body is provided with at least one in-situ detection device corresponding to the tray. The in-situ detection device is used for carrying out real-time detection on the crystal epitaxial layer, the epitaxial furnace body is provided with a window corresponding to the in-situ detection device, and the in-situ detection device is arranged on the epitaxial furnace body, so that real-time online monitoring on the epitaxial layer is realized, growth information of the epitaxial layer can be obtained in time, and the design is ingenious.

The present invention provides an anti-backflow gas transport device and method for vapor phase epitaxial growth. The device has a nozzle structure and at least includes a multi-channel pipeline inlet, a multi-channel gas transport pipeline, a multi-channel pipeline outlet, a nozzle multi-channel pipeline outlet, an internal reaction chamber, and multiple variable-diameter anti-backflow plates. By arranging anti-backflow plates at the multi-channel pipeline outlet to form a funnel-like structure, it is possible to avoid the phenomenon that the outlet of the gas outlet pipe is affected by the surrounding gas to form turbulence and even cause fluid backflow due to the small cross-sectional area, large flow rate, and small pressure of the multi-channel pipeline outlet. The present invention avoids the siphon backflow phenomenon at the nozzle due to the too large flow rate of a single pipeline outlet by regulating the pressure difference of the nozzle multi-channel pipeline outlet. By regulating the laminar flow transport of the gas, the particles generated by pre-reaction can be effectively reduced, thereby improving the crystal quality. The structure of the present invention is simple, easy to manufacture, and has strong practicability, and has extremely high commercial value.

The utility model relates to a kind of cleaning device for cleaning MOCVD equipment deposit, belong to the technology in the field of semiconductor, including reaction cavity and storage cavity, the reaction cavity and storage cavity are communicated, cleanable cleaning device is installed in the reaction cavity;Driving device for driving cleaning device to move and rotate cleaning inner wall of reaction cavity is installed in the storage cavity;The utility model can clean the deposit accumulated in cavity on the basis of not disassembling reaction cavity body, avoid the inside of reaction cavity body and atmospheric contact adsorption water vapor, oxygen and other impurities.The cleanliness of the inside of reaction cavity body is maintained, and the stability of machine performance after cavity maintenance is improved.And it can also move cleaning device to the top of mobile cavity, reduce use and storage space, without affecting the effect of gas phase epitaxy on the substrate surface inside the reaction chamber.

The present invention provides a method for preparing a gallium oxide epitaxial wafer, an epitaxial growth system and a gallium oxide epitaxial wafer. The method comprises: placing a (100)-surface gallium oxide substrate in a reaction chamber, introducing a carrier gas of a first preset flow rate, setting the pressure in the reaction chamber to the first preset pressure, and heating the reaction chamber to a first preset temperature; introducing a second preset flow rate of hydrogen to pretreat the (100)-surface gallium oxide substrate; setting the pressure in the reaction chamber to the second preset pressure, heating the source region to the second preset temperature, and heating the growth region to a third preset temperature; introducing a third preset flow rate of hydrogen chloride, a fourth preset flow rate of oxygen and a fifth preset flow rate of hydrogen in the reaction chamber to perform gas phase epitaxy, so as to prepare a (100)-surface gallium oxide epitaxial film on the surface of the (100)-surface gallium oxide substrate. The present invention can promote step flow growth, reduce polycrystalline particle aggregation, reduce three-dimensional island growth, and improve the surface continuity and quality of the epitaxial film.

The present invention is a method for manufacturing an epitaxial wafer, for forming a single-crystal silicon layer on a silicon single-crystal wafer. The method is characterized by comprising a hydrofluoric acid cleaning step for removing a natural oxide film from the surface of the silicon single-crystal wafer with a cleaning liquid containing hydrofluoric acid, an oxygen atomic layer forming step for forming, by cleaning, an oxygen atomic layer on the surface of the silicon single-crystal wafer from which the natural oxide film has been removed, and an epitaxial growth step for epitaxially growing, by a vapor-phase growth method, the single-crystal silicon layer on the surface of the silicon single-crystal wafer on which the oxygen atomic layer has been formed, wherein a cleaning liquid containing at least hydrogen peroxide water is used for the cleaning in the oxygen atomic layer forming step. Thus, a method for manufacturing an epitaxial wafer is provided that makes it possible to efficiently form and control an oxygen atomic layer without causing a deterioration in the surface roughness of the wafer.

A Metalorganic chemical vapor phase epitaxy or vapor phase deposition apparatus, having a first gas source system, a reactor, an exhaust gas system, and a control unit, wherein the first gas source system has a carrier gas source, a bubbler with an organometallic starting compound, and a first supply section leading to the reactor either directly or through a first control valve, the carrier gas source is connected to an inlet of the bubbler through a first mass flow controller by a second supply section, an outlet of the bubbler is connected to the first supply section, and the carrier gas source is connected to the first supply section through a second mass flow controller by a third supply section, the first supply section is connected to an inlet of the reactor through a third mass flow controller.

The present invention relates to the technical field related to GaN preparation, and discloses a self-revolving base for a gas phase epitaxial reaction chamber structure, comprising a substrate support and an embedded substrate, wherein the embedded substrate is arranged on the inner side of the substrate support, and a plurality of embedded openings are provided in a circular array on the surface of the embedded substrate. In the self-revolving base for a gas phase epitaxial reaction chamber structure, when the process gas overflows through the gap between the cavity substrate body and the inner side wall of the embedded opening, the annular flow blocking slope can effectively prevent the process gas from overflowing vertically downward, and the setting of the annular flow blocking groove blocks the process gas overflowing and refluxing vertically downward, and at the same time, the setting of the annular flow limiting slope and the annular limiting groove further reduces the overflow reflux gas from being led out through the gap between the annular embedded ring and the annular embedded groove, and minimizes the overflow of the process gas under the premise of ensuring the stable coordinated activities between the structures, thereby effectively ensuring the supply reaction efficiency of the process gas.

The invention provides a gas inlet device and vapor phase epitaxial growth equipment. The gas inlet device comprises a gas uniformizing plate, a buffer plate, an inner pipe, an outer pipe and a gas inlet pipe, wherein the gas uniformizing plate and the buffer plate are attached to each other; the inner pipe continuously penetrates through the gas uniformizing plate and the buffer plate; an outer side conveying channel for conveying a first growth gas source is formed between the outer pipe and the inner pipe, the inner pipe partially extends into the outer pipe, an annular gas uniformizing cavity is formed in the gas uniformizing plate, a sieve plate with through holes is arranged in the buffer plate, and at least one layer of annular buffer cavity is formed by the sieve plate and the gas uniformizing plate; the gas inlet pipe is communicated with the annular gas uniformizing cavity, the gas inlet pipe inputs a first growth gas source into the annular gas uniformizing cavity, and the first growth gas source is injected into the buffer cavity after being distributed by at least one gas uniformizing hole formed by the annular gas uniformizing cavity and communicated with the buffer cavity, so that the first growth gas source is injected from the sieve plate to the outer side conveying channel to form laminar flow. The gas flow distribution uniformity of the first growth gas source in the epitaxial growth region is improved, and the method can be used for growing gallium nitride crystals.

The invention belongs to the technical field of crystal growth control, and particularly relates to a vapor phase epitaxial growth temperature flow cooperative control method and system.The method comprises the steps that the heating power, the real-time temperature and the process gas flow of each temperature zone of a reaction chamber are collected in real time; constructing an equivalent thermal coupling gap factor representing the local geometric deformation trend of the wafer based on the heating power and the real-time temperature; deducing a mass transfer boundary layer distortion index in combination with the equivalent thermal coupling gap factor and the process gas flow; calculating an equivalent resistivity temperature compensation instruction according to the influence on the doping mass transfer efficiency; and after safe amplitude limiting and smoothing treatment, the multi-temperature-zone heating system is driven to execute non-uniform cooperative regulation and control. According to the method, the problem that the temperature is uniform but the resistance is not uniform is effectively solved, and the global uniformity and the process stability of the surface resistance of the epitaxial layer on the large-size wafer are improved.

This invention belongs to the field of crystal growth control technology, specifically relating to a method and system for coordinated temperature and flow control in vapor phase epitaxial growth. The method includes: real-time acquisition of heating power, real-time temperature, and process gas flow rate in each temperature zone of the reaction chamber; after time alignment and filtering, constructing an equivalent thermal coupling gap factor characterizing the local geometric deformation trend of the wafer based on the heating power and real-time temperature; deriving the mass transfer boundary layer distortion index by combining the equivalent thermal coupling gap factor and the process gas flow rate; calculating the equivalent resistivity temperature compensation command based on its impact on doping mass transfer efficiency; and driving the multi-temperature zone heating system to perform non-uniform coordinated control after safety limiting and smoothing processing. This invention effectively alleviates the problem of uniform temperature but non-uniform resistance, improving the global uniformity of surface resistance and process stability of epitaxial layers on large-size wafers.

The present invention discloses a method and apparatus for growing a III-V compound single crystal by hydride vapor phase epitaxy. The method comprises: introducing a III element source, a nitrogen source, and a carrier gas into a HVPE reaction chamber, and sequentially passing through a first region, a second region, and a third region of the reaction chamber, adjusting the first region, the second region, and the third region of the reaction chamber to a first temperature, a second temperature, and a third temperature, respectively, causing the III element source and the nitrogen source to react in the first region to form a III nitride single crystal, causing the III element source and hydrogen to react in the second region to form a III element element, and causing the nitrogen source and a halogen hydride to react in the third region to form an ammonium salt. An embodiment of the present invention provides a method for growing a III nitride single crystal by hydride vapor phase epitaxy, which improves the yield and purity of the III nitride single crystal, can recover the III element element element, and reduces the preparation cost of the III nitride single crystal.

The application relates to a semiconductor structure, a self-supporting doped gallium nitride layer and a preparation method of the semiconductor structure. The preparation method of the semiconductor structure comprises the following steps: providing a substrate; placing the substrate in a hydride vapor phase epitaxy device; introducing a nitrogen-containing gas and a silicon-containing mixed gas into the hydride vapor phase epitaxy device, the nitrogen-containing gas and the silicon-containing mixed gas react to form a patterned mask layer on the substrate, and the patterned mask layer has a plurality of pores; after adjusting the flow of the silicon-containing mixed gas, continuously introducing the silicon-containing mixed gas and the nitrogen-containing gas into the hydride vapor phase epitaxy device; and introducing hydrogen chloride gas into the hydride vapor phase epitaxy device to form a doped gallium nitride layer in the pores and on the surface of the patterned mask layer away from the substrate. The preparation method provided by the above embodiment is not easy to introduce new pollution, and can simplify the design of the hydride vapor phase epitaxy device.

The invention discloses a preparation method and application of a GaN thick film without stress residue. The preparation method is characterized by comprising the following steps: (1) providing a heterogeneous substrate; (2) depositing a layer of low-temperature GaN by utilizing MOCVD (Metal Organic Chemical Vapor Deposition), and doping one doping source of Si, C or O in the process to form a pre-stress buried layer; (3) evaporating and depositing a layer of mask on the prestressed buried layer by using PECVD (Plasma Enhanced Chemical Vapor Deposition) or magnetron sputtering technology, and forming a patterned mask by using the photoetching hole type array; (4) epitaxially growing 3D island-shaped GaN on the patterned mask by using hydride vapor phase epitaxy; (5) growing a GaN single crystal non-doped layer on the 3D island-shaped GaN; (6) growing Ge-doped GaN on the GaN single crystal non-doped layer; and (7) cooling in the furnace to form a GaN thick film, and selectively corroding the N surface of the GaN thick film in the corrosive liquid to obtain the GaN thick film. The method has the beneficial effect that the GaN bulk material without invisible cracks and residual stress is obtained.

This invention discloses a time-controlled vapor-phase epitaxial reaction chamber, apparatus, and method for producing hydrides. The reaction chamber includes: a chamber with water-cooled sidewalls and a cavity defined by flanges, the cavity being divided into upper, middle, and lower sections; a metal source reaction boat assembly located in the upper half of the reaction chamber; a time-controlled reaction growth apparatus located in the middle of the reaction chamber; a heating device and a tail gas collection device located in the lower half of the reaction chamber; and a central gas path device located at the axial position of the reaction chamber, connecting the metal source reaction boat assembly in the upper half of the chamber and the time-controlled reaction growth apparatus in the middle of the chamber. This invention controls the growth time precisely by combining time modulation and spatial modulation, thereby increasing the flexibility of the growth program settings and enabling rapid epitaxial growth of ultra-thin and ultra-thick material stacked structures, meeting the low-cost epitaxial growth requirements of complex semiconductor devices.

This invention discloses a heteroepitaxial composite substrate with in-situ thermo-mechanical coupling suppression characteristics and its fabrication method. The substrate is prepared by continuously growing lattice-coherent stress-relieving, compositional equilibrium, and pre-stress compensation sections on a single-crystal silicon support substrate using vapor phase epitaxy. Through the synergistic effect of a step-decreasing germanium composition and a pulsed fluctuating carbon composition, an asymmetric strain field is constructed in-situ within the single-crystal lattice. Cyclic thermal annealing during fabrication enables deep pinning of penetrating dislocations and precise arrangement of the micro-strain trap array. This invention not only solves the inherent lattice constant mismatch problem in heteroepitaxial growth but also ensures extremely high single-crystal quality and structural integrity of the top epitaxial layer through in-situ strain engineering, achieving dynamic stress balance within the material system over a wide temperature range.

The invention relates to the technical field of III-V group compound semiconductor epitaxial growth, in particular to a mixed type rapid vapor phase epitaxial growth system and method. The system comprises a main reaction cavity module and an external generation device module, and the main reaction cavity module adopts an MOCVD structure and is used for bearing a substrate and completing III-V multi-layer epitaxial growth; and the external generation device module is arranged outside the main reaction cavity and is used for introducing the III-group chloride reaction source into the main reaction cavity, the III-group chloride reaction source and the introduced V-group gas source are subjected to an inorganic chemical reaction on the surface of the substrate, and a target epitaxial film layer grows. The process control unit cooperatively adjusts the flow, temperature and cavity pressure of the III-group chloride and the V-group gas source according to in-situ monitoring signals, and can be switched between HVPE type rapid growth and MOCVD fine growth or used in a combined mode. According to the method, the growth rate of the thick layer is remarkably improved, and the method is suitable for large-scale and low-cost preparation of space III-V group solar cells.

The invention provides a hydride vapor phase epitaxy filter, a filter cleaning device and a cleaning method, the hydride vapor phase epitaxy filter comprises a shell and a pressure-resistant stopper, the shell is provided with a pressurizing port and a dust discharge port, and the pressure-resistant stopper is arranged in the dust discharge port. The hydride vapor phase epitaxy filter has a first state in which the pressure is maintained and a second state in which the pressure is instantaneously released, in the first state, there is a stable pressure difference between the interior of the housing and the collection structure, and the dust discharge port is instantaneously opened by the pressure-resistant stopper, and the dust discharge port is instantaneously opened by the pressure-resistant stopper. And the shell is in the second state, and dust in the shell enters the collecting structure. According to the invention, the dust cleaning efficiency, the operation safety, the process compatibility and the material quality guarantee can be comprehensively improved, and an efficient and stable tail gas treatment solution is provided for the gallium nitride epitaxial growth process.

The invention provides a gas phase epitaxy equipment filter cleaning device and method and a tail gas recovery system. The gas phase epitaxy equipment filter cleaning device comprises a mounting frame; the moving mechanism comprises a first clamping assembly, and the first clamping assembly can drive the filter to be cleaned to turn over; and the cover moving mechanism comprises a second clamping assembly, and the second clamping assembly is used for disassembling and assembling the top cover of the filter. A stable and reliable supporting foundation is provided for the whole structure through the mounting frame, and stable operation of all executing mechanisms is ensured. The first clamping assembly can drive the filter to turn over, so that dust deposited in the filter is directionally dumped under the action of gravity, and a second clamping assembly in the cover moving mechanism is matched to automatically disassemble and assemble a top cover of the filter, so that full-process operation of cover opening, turning over to remove dust and cover closing is formed. Compared with existing cleaning equipment, the sealing performance and the dust collection rate in the cleaning process are improved, and stable operation of vapor phase epitaxy equipment and the treatment efficiency of a tail gas recovery system are effectively guaranteed.

The invention discloses a halide vapor phase epitaxial growth system and a use method thereof, and belongs to the technical field of semiconductor materials, the halide vapor phase epitaxial growth system comprises a quartz tube body, a metal gallium chamber located in the quartz tube body, a ventilation pipeline, a substrate and three baffles, the three baffles are sequentially arranged in the quartz tube body at intervals and divide the quartz tube body into four cavities, gas is introduced into the ventilation pipeline, and the gallium metal cavity is located in the third cavity in the gas flow direction and used for containing gallium metal. According to the growth system provided by the invention, the three baffles are arranged in the quartz tube body, so that impurity deposition on the inner wall of the chamber and the GaClx outlet tube is effectively reduced, the influence on the growth stability and uniformity of a gallium oxide epitaxial film due to the existence of by-product impurities is avoided, the cleaning cost of the chamber is reduced, and the production efficiency is improved. And the thickness difference between the edge and the central position of the epitaxial film is ensured to be within 10%.

The invention belongs to the technical field of vapor phase epitaxy, and relates to a raw material monitoring and supplementing method and a vapor phase epitaxy device. The raw material monitoring and supplementing method is applied to a control device in the vapor phase epitaxy device, the vapor phase epitaxy device further comprises a growth device and a monitoring device coupled with the control device, the growth device comprises a reaction chamber and a supplementing chamber, the monitoring device is arranged in the reaction chamber, and a supplementing boat and a raw material adding device are arranged in the supplementing chamber. The method comprises the following steps: acquiring raw material condition information of a raw material boat monitored by a monitoring device; processing the raw material condition information to obtain liquid level variation or weight variation of the raw materials; and when the liquid level reduction amount is larger than a first preset value or the weight reduction amount is larger than a second preset value, an adding instruction is sent to the raw material adding device, so that the raw material adding device supplements the raw materials in the supplementing boat to the raw material boat. The scheme solves the problem that the growth rate and the growth concentration are influenced by raw material fluctuation, can improve the product quality, and can be used for growing gallium nitride.

The application belongs to the technical field of vapor phase epitaxy and relates to a vapor phase epitaxy device capable of being used for growing gallium nitride; the vapor phase epitaxy device comprises a control device and a growth device; the growth device comprises a reaction chamber, a raw material boat, a raw material supplementing chamber, a supplementing boat, an automatic adding device and a sensor; the raw material boat is arranged in the reaction chamber and is used for containing raw materials; the raw material supplementing chamber is communicated with the reaction chamber; the supplementing boat is arranged in the raw material supplementing chamber and is used for containing supplemented raw materials; the automatic adding device is arranged in the raw material supplementing chamber; the sensor is arranged in the reaction chamber and is coupled with the control device and is used for monitoring information of the raw materials; the control device obtains change information of the raw materials in the raw material boat based on the information of the raw materials, and controls the automatic adding device to supplement the raw materials to the raw material boat when the change information meets preset raw material supplementing conditions. The scheme solves the problems of the influence of raw material fluctuation on growth rate and growth concentration through the monitoring and automatic supplementing closed loop of the raw materials.

A vapor phase epitaxy method of growing a III-V layer with a doping profile that changes from n-doping to p-doping on a surface of a substrate or a preceding layer in a reaction chamber from the vapor phase of an epitaxial gas flow, comprising at least one carrier gas, a first precursor for a first element from main group III and at least one second precursor for a first element from main group V, and fed into the reaction chamber, wherein, when a first growth level is reached, an initial n-doping level is set by means of a ratio, leading to a p-doping, of a first mass flow of the first precursor to a second mass flow of the second precursor in the epitaxial gas flow and with the addition of a third mass flow of a third precursor for an n-type dopant to the epitaxial gas flow, subsequently.

The invention discloses a Ceiling temperature adjusting system and method for metal vapor phase epitaxy equipment. The system comprises a heating unit, a first temperature detection unit, a hydrogen input channel, a nitrogen input channel, a gas mixing channel, a first control unit and a second control unit. A hydrogen flow adjusting unit is arranged on the hydrogen input channel, and a nitrogen flow adjusting unit is arranged on the nitrogen input channel; the heating unit is used for heating the large graphite plate; the first temperature detection unit is connected with the control unit and is used for detecting the temperature of the Ceiling large disc; the first control unit is connected with the hydrogen flow adjusting unit and the nitrogen flow adjusting unit and used for adjusting the opening degree of the hydrogen flow adjusting unit or / and the opening degree of the nitrogen flow adjusting unit according to the temperature of the Ceiling large disc so as to keep the surface temperature of the Ceiling large disc stable. The device has the advantages of being accurate in temperature adjustment, low in airflow disturbance and the like.

The application discloses a preparation method of a self-supporting GaN substrate based on graphene and relates to the technical field of semiconductor devices. The preparation method comprises the following steps: performing pattern processing on a graphene layer on a substrate layer to prepare a graphene mask region with a plurality of window regions arranged at intervals; depositing a GaN thin film in the graphene mask region by using a metal organic chemical vapor deposition process until the GaN thin film of the window region forms a gap with the substrate layer; depositing a GaN film layer on the GaN thin film by using a hydride vapor phase epitaxy process, and obtaining a self-supporting GaN substrate after a stripping treatment; wherein the temperature of a nucleation growth stage is 550 DEG C-600 DEG C, and the temperature of an annealing crystallization stage is 1050 DEG C-1100 DEG C. The application realizes the significant reduction of the interface bonding strength between a GaN epitaxial layer and a substrate while ensuring the high-quality growth of the GaN epitaxial layer, so that the lossless stripping can be realized and a high-quality self-supporting GaN substrate can be obtained.

The invention relates to a SiC coating graphite disc used for a large-size high axial temperature gradient working condition and a preparation method thereof.The SiC coating graphite disc comprises a graphite base body and SiC coatings, a plurality of pits are formed in one side face of the graphite base body, the SiC coatings are deposited in the pits and on the side face of the graphite base body, the distance between the centers of the adjacent pits is 150-200 micrometers, the thickness of each SiC coating is 30-50 micrometers, and the thickness of each SiC coating is 30-50 micrometers. The grain size of the SiC coating ranges from 100 micrometers to 130 micrometers. The preparation method comprises the following steps: S1, processing one side surface of a graphite substrate to form a plurality of pits; and S2, depositing on the pits and the side surface of the graphite substrate through chemical vapor deposition. According to the invention, large crystal grains (dozens of microns) are formed in the pits, and then through vapor phase epitaxial growth, the crystal grains transversely grow until the crystal grains are completely combined, and finally ultra-large crystal grains with the size of 100-130 microns are formed; and after the transverse combination, the crystal grains continuously and vertically grow to 30-50 [mu] m to obtain the SiC coating.