A method for continuous preparation of HFCVD diamond film

Abstract

The invention discloses a HFCVD diamond film continuous preparation method, comprising the following steps: a hot wire method production device is provided with a deposition space, wherein the deposition space comprises a deposition base; the deposition base comprises a deposition substrate and a cooling platform, wherein the deposition substrate is placed on the upper surface of the cooling platform; the cooling platform comprises a first support block, a second support block and a cooling device; the second support block and the first support block are sequentially placed above the cooling device; the deposition substrate is placed on the upper surface of the first support block; the hot wire method production device is adjusted by a thermal structure compensation method for diamond deposition, and a new batch of diamond film production is carried out to achieve continuous production of diamond film; the problem of defects or even cracking of the deposited diamond film caused by residues and deformation on the surface of the deposition substrate and the cooling platform is avoided, and the problem of an increase in graphite phase in the diamond film is avoided, so that the diamond films prepared in continuous batches have fewer impurities and defects and the quality of the diamonds prepared in continuous batches is similar.

Description

Technical Field

[0001] The invention relates to the field of diamond film preparation, and in particular to the field of a HFCVD diamond film continuous preparation method. Background Art

[0002] Diamond has the highest hardness in nature, excellent wear resistance, high thermal conductivity, high transmittance in a wide spectral range and other characteristics, and has great application value in many fields. The CVD method for preparing diamond has the advantages of high quality, good uniformity, high controllability and low cost, and is currently a hot technology for industrial preparation and academic research of diamond. Among the different CVD preparation methods for diamond, the HFCVD method (hot wire chemical vapor deposition method) has simple equipment, low cost, good uniformity, and is suitable for large-area and curved surface preparation, making it the preferred method for industrial preparation of diamond films.

[0003] In the HFCVD equipment, the carbon source gas and hydrogen are decomposed into atomic hydrogen and carbon-containing groups near the high-temperature hot wire, and then transported to the deposition base to deposit on the surface to form a diamond film.

[0004] In the current HFCVD diamond film production process, there is a problem that the deposition substrate and the cooling stage will deform slightly at high temperature, and there will be carbide generation and residue on the outer surface of the deposition substrate and the cooling stage. As a result, when the diamond film is continuously produced, that is, after the previous batch is produced, the next batch will be produced due to the residue and deformation on the deposition substrate and the cooling stage surface, resulting in defects or even cracks in the deposited diamond film, and the problem of increased graphite phase in the diamond film.

[0005] Therefore, how to achieve continuous preparation of diamond films while avoiding residues and deformation on the surface of the deposition substrate and the cooling platform, which may lead to defects or even cracks in the deposited diamond films, and how to avoid an increase in graphite phase in the diamond films, so as to achieve continuous batch preparation of diamond films with fewer impurities and defects and similar quality of diamonds prepared in continuous batches has become a difficult problem that needs to be solved urgently in this field. Summary of the invention

[0006] In order to solve the above technical problems, a method for continuous preparation of HFCVD diamond films is provided, which can achieve the goal of avoiding defects or even cracking of the deposited diamond film caused by residues and deformation on the surface of the deposition substrate and the cooling table during the continuous preparation of the diamond film, and avoiding the problem of increased graphite phase in the diamond film, so as to achieve continuous batch preparation of diamond films with fewer impurities and defects and similar quality of diamonds prepared in continuous batches.

[0007] According to the present invention, a method for continuously preparing a HFCVD diamond film is provided, comprising the following steps:

[0008] Production of diamond films by hot wire production apparatus;

[0009] The hot wire production device is provided with a deposition space, wherein the deposition space includes a hot wire assembly and a deposition base;

[0010] The hot wire assembly comprises a plurality of hot wires arranged in parallel;

[0011] The deposition base comprises a deposition substrate and a cooling platform, wherein the deposition substrate is placed on the upper surface of the cooling platform;

[0012] The cooling platform comprises a first support block, a second support block, and a cooling device; the second support block and the first support block are sequentially placed above the cooling device; the deposition substrate is placed on the upper surface of the first support block;

[0013] Measure the thickness d1 of the first support block, the thickness d2 of the second support block, and the thickness d3 of the deposition substrate;

[0014] Measuring the distance D between the plane of the hot wire assembly and the plane of the deposition substrate;

[0015] evacuating the deposition space;

[0016] Introduce hydrogen and methane in proportion to the target pressure;

[0017] Then, the hot wire is turned on to heat the upper surface of the deposition substrate to a preset temperature;

[0018] When the thickness of the diamond film deposited on the surface of the deposition substrate reaches a preset requirement, the hot wire heating is turned off and the temperature is lowered; preferably, when the deposition time after heating reaches a preset time, the thickness of the diamond film deposited on the surface of the deposition substrate reaches a preset requirement;

[0019] After the temperature is lowered, the hydrogen in the furnace is exhausted, and after the furnace is inflated to atmospheric pressure, the diamond film layer is removed from the surface of the deposition substrate to obtain the diamond film layer;

[0020] Then, the hot wire production device is adjusted by the thermal structure compensation method of diamond deposition to produce a new batch of diamond films, thereby realizing continuous production of diamond films;

[0021] Preferably, after the upper surface of the deposition substrate reaches a preset temperature, the cooling device is turned on to cool the first support block, the second support block, and the lower surface of the deposition substrate.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the cooling stage includes the first support block, the second support block, and the cooling device, so that the cooling device can cool the deposition substrate, the first support block, and the second support block during the diamond film deposition process; and the first support block and the second support block are more conducive to achieving uniform overall cooling of the deposition substrate in the cooling process than only the first support block, and at the same time, a large amount of heat waste in the deposition process caused by the excessively low interface temperature between the deposition substrate and the first support block is avoided, thereby saving a large amount of energy for continuous production;

[0023] By measuring the thickness d1 of the first support block, the thickness d2 of the second support block, the thickness d3 of the deposition substrate, and the distance D between the plane of the hot wire assembly and the plane of the deposition substrate, the quality of the diamond film produced in each batch can be basically consistent by adjusting the hot wire production device;

[0024] Through the thermal structure compensation method of diamond deposition, the hot wire production equipment is adjusted to produce a new batch of diamond films, so as to achieve the continuous preparation of diamond films, avoid the residue and deformation of the deposition substrate and the cooling table surface, which may cause defects or even cracks in the deposited diamond films, and avoid the problem of increased graphite phase in the diamond films, so as to achieve continuous batches of diamond films with less impurities and defects and similar quality of diamonds.

[0025] Furthermore, the hydrogen and methane are introduced to a target pressure of 2000-8000Pa;

[0026] Furthermore, the volume ratio of methane to hydrogen is (2-10):(90-98).

[0027] By adopting the beneficial effect of the previous step, full and uniform contact between hydrogen and methane is achieved, which is conducive to uniform and defect-free diamond deposition.

[0028] Furthermore, the preset temperature of the upper surface of the deposition substrate is 800-1000°C.

[0029] The beneficial effect of adopting the previous step is that it helps to avoid the appearance of graphite phase during the diamond film deposition process.

[0030] Furthermore, the thermal structure compensation method for diamond deposition comprises the following steps:

[0031] After the diamond film layer is removed from the surface of the deposition substrate, the upper surface and the lower surface of the first support block, the upper surface of the second support block, and the upper surface and the lower surface of the deposition substrate are polished and smoothed;

[0032] Measure the thickness d1' of the first support block after grinding, the thickness d2' of the second support block after grinding, and the thickness d3' of the deposited substrate after grinding;

[0033] The thickness d3' of the deposited substrate after grinding is judged, and when the thickness d3' of the deposited substrate after grinding meets the range of the deposited substrate, a third support block is added between the deposited substrate and the cooling device;

[0034] When the thickness d3' of the deposited substrate after grinding does not meet the deposited substrate range, a new deposited substrate is replaced.

[0035] The beneficial effect of adopting the previous step is that after the diamond film layer is removed from the surface of the deposition substrate, the upper surface and the lower surface of the first support block, the upper surface of the second support block, and the upper surface and the lower surface of the deposition substrate are polished and flattened, so as to remove the residual substances on the surface of the deposition substrate, the surface of the first support block, and the surface of the second support block in the process of producing diamond films in the previous batch, and at the same time, the problem of surface deformation of the deposition substrate, the first support block, and the second support block in the process of producing diamond films in the previous batch is eliminated; thereby facilitating the continuous preparation of diamond films, avoiding the problem of defects or even cracks in the deposited diamond film caused by residual and deformation on the surface of the deposition substrate and the cooling stage, and avoiding the problem of increased graphite phase in the diamond film;

[0036] After the deposition substrate, the first support block and the second support block are polished and flat, there are problems: the distance between the plane of the hot wire assembly and the plane of the deposition substrate changes, and the distance between the plane of the deposition substrate and the cooling device changes, which causes the temperature of the surface of the deposition substrate to change, resulting in changes in the thermal insulation performance and cooling conditions under the deposition substrate;

[0037] By measuring the thickness d1' of the first support block after grinding, the thickness d2' of the second support block after grinding, and the thickness d3' of the deposition substrate after grinding, it is helpful to solve the problem of temperature changes on the surface of the deposition substrate, and to solve the problem of changes in thermal insulation performance and cooling conditions under the deposition substrate.

[0038] Further, when a third support block is added between the deposition substrate and the cooling device, the thickness d4 of the third support block is obtained by formula 1 and formula 2;

[0039] Formula 1: Δθ=[1 / λ3*(d3-d3')+1 / λ2*(d2-d2')+1 / λ1*(d1-d1')] / S;

[0040] Formula 2: d4=Δθ*λ4*S;

[0041] The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition base; Δθ is the thermal resistance lost after grinding;

[0042] λ4=λ1 or λ2.

[0043] By adopting the method of the previous step and adding a third support block, it is helpful to eliminate the change in the distance between the plane of the hot wire assembly and the plane of the deposition substrate; the thickness d4 of the third support block obtained by Formula 1 and Formula 2 is helpful to eliminate the problem of changes in the cooling effect on the back of the deposition substrate caused by changes in the distance between the plane of the deposition substrate and the cooling device.

[0044] Further, when a new deposition substrate is replaced, the distance D' between the deposition substrate plane and the hot wire assembly plane after the deposition substrate is replaced;

[0045] D' is calculated by formula 3 and formula 4;

[0046] Formula 3: θ=(1 / λ3*d3+1 / λ2*d2+1 / λ1*d1) / S;

[0047] θ'=(1 / λ3*d 30 +1 / λ2*d2'+1 / λ1*d1') / S;θ eff =θ / θ';

[0048] Formula 4: D'=D*(1 / θ eff ) 1 / 2 ;

[0049] The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition platform; d 30 is the thickness of the new deposited substrate; θ is the thermal resistance before replacing the new deposited substrate; θ' is the thermal resistance after replacing the new deposited substrate.

[0050] By adopting the method of the previous step, a new deposition substrate is replaced, and the distance D' between the deposition substrate plane and the hot wire assembly plane after the new deposition substrate is replaced is calculated by Formula 3 and Formula 4, which is conducive to achieving the deposition temperature on the deposition substrate surface and the cooling effect on the back of the deposition substrate after the distance between the deposition substrate plane and the cooling device changes, which is basically consistent with the deposition temperature on the deposition substrate surface and the cooling effect on the back of the deposition substrate when depositing the previous batch of diamond films.

[0051] Furthermore, the upper surface area of ​​the deposition base, the upper surface area of ​​the deposition substrate, the lower surface area of ​​the deposition substrate, the upper surface area of ​​the first support block, the lower surface area of ​​the first support block, the upper surface area of ​​the second support block, the upper surface area of ​​the third support block, and the lower surface area of ​​the third support block are the same.

[0052] Further, the cooling device includes a cooling medium storage container;

[0053] The cooling medium storage container is provided with a liquid inlet and a liquid outlet, and the liquid inlet is connected to a cold source;

[0054] The upper surface of the medium storage container is connected to the second supporting block.

[0055] The beneficial effect of adopting the above step is that the deposition substrate, the first support block and the second support block can be cooled.

[0056] Furthermore, the material of the third support block is the same as the material of the first support block or the material of the second support block;

[0057] The cooling medium in the cooling device is water, and the outlet water temperature of the cooling medium is 40-60°C;

[0058] and / or

[0059] The interface temperature between the deposition substrate and the first support block is 480-560°C; the interface temperature between the second support block and the first support block is 120-160°C;

[0060] Preferably, the deposition substrate material is one of silicon, molybdenum, tungsten, graphite, and silicon carbide; the first support block material is one of silicon, silicon nitride, silicon carbide, molybdenum, tungsten, graphite, copper, and iron; the second support block material is one of silicon, silicon nitride, silicon carbide, molybdenum, tungsten, graphite, copper, and iron.

[0061] The beneficial effect of adopting the previous step is that the interface temperature between the deposition substrate and the first support block is 480-560°C; the interface temperature between the second support block and the first support block is 120-160°C, so that the surface temperature of the deposition substrate is 800-1000°C, which is conducive to uniform deposition of the diamond film and unfavorable to the formation of defects and graphite phases, and is conducive to avoiding the problem of large-scale deformation of the deposition substrate, the first support block and the second support block due to high temperature; in addition, the interface temperature between the deposition substrate and the first support block is 480-560°C, which avoids a large amount of heat waste during the deposition process due to the excessively low interface temperature between the deposition substrate and the first support block, thereby saving a large amount of energy for continuous production. DETAILED DESCRIPTION

[0062] In order to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments.

[0063] Embodiment 1:

[0064] This embodiment provides a method for continuously preparing a HFCVD diamond film, comprising the following steps:

[0065] Production of diamond films by hot wire production apparatus;

[0066] The hot wire production device is provided with a deposition space, wherein the deposition space includes a hot wire assembly and a deposition base;

[0067] The hot wire assembly comprises a plurality of hot wires arranged in parallel;

[0068] The deposition base comprises a deposition substrate and a cooling platform, wherein the deposition substrate is placed on the upper surface of the cooling platform;

[0069] The cooling platform comprises a first support block, a second support block, and a cooling device; the second support block and the first support block are sequentially placed above the cooling device; the deposition substrate is placed on the upper surface of the first support block; the cooling device comprises a cooling medium storage container;

[0070] The cooling medium storage container is provided with a liquid inlet and a liquid outlet, and the liquid inlet is connected to a cold source; the upper surface of the medium storage container is connected to a second support block;

[0071] The deposition substrate is made of molybdenum; the first support block is made of graphite; and the second support block is made of copper.

[0072] The cooling medium in the cooling device is water, and the outlet water temperature of the cooling medium is 50°C;

[0073] Measure the thickness d1 of the first support block, the thickness d2 of the second support block, and the thickness d3 of the deposition substrate;

[0074] Measuring the distance D between the plane of the hot wire assembly and the plane of the deposition substrate;

[0075] evacuating the deposition space;

[0076] Introducing hydrogen and methane in proportion to a target pressure; the introducing hydrogen and methane to a target pressure of 5000 Pa; the volume ratio of methane to hydrogen is 6:94;

[0077] The preset temperature of the upper surface of the deposition substrate is 900°C;

[0078] The cooling device was turned on, and the interface temperature between the deposition substrate and the first support block was 500°C; the interface temperature between the second support block and the first support block was 150°C.

[0079] Then, the hot wire is turned on to heat the upper surface of the deposition substrate to a preset temperature;

[0080] When the thickness of the diamond film deposited on the surface of the deposition substrate reaches the preset requirement, the hot wire heating is turned off and the temperature is lowered; that is, after the preset heating time is reached, the hot wire heating is turned off and the temperature is lowered;

[0081] After the temperature is lowered, the hydrogen in the furnace is exhausted, and after the furnace is inflated to atmospheric pressure, the diamond film layer is removed from the surface of the deposition substrate to obtain the diamond film layer;

[0082] Then, the hot wire production device is adjusted by the thermal structure compensation method of diamond deposition to produce a new batch of diamond films, thereby realizing continuous production of diamond films;

[0083] The thermal structure compensation method for diamond deposition comprises the following steps:

[0084] After the diamond film layer is removed from the surface of the deposition substrate, the upper surface and the lower surface of the first support block, the upper surface of the second support block, and the upper surface and the lower surface of the deposition substrate are polished and smoothed;

[0085] Measure the thickness d1' of the first support block after grinding, the thickness d2' of the second support block after grinding, and the thickness d3' of the deposited substrate after grinding;

[0086] The thickness d3' of the deposited substrate after grinding is judged, and when the thickness d3' of the deposited substrate after grinding is within the range of the deposited substrate, a third support block is added between the deposited substrate and the cooling device;

[0087] When the thickness d3' of the deposited substrate after grinding does not meet the deposited substrate range, a new deposited substrate is replaced;

[0088] When a third support block is added between the deposition substrate and the cooling device, the thickness d4 of the third support block is obtained by formula 1 and formula 2;

[0089] Formula 1: Δθ=[1 / λ3*(d3-d3')+1 / λ2*(d2-d2')+1 / λ1*(d1-d1')] / S;

[0090] Formula 2: d4=Δθ*λ4*S;

[0091] The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition base; Δθ is the thermal resistance lost after grinding; λ4 = λ1 or λ2; the material of the third support block is the same as that of the first support block;

[0092] When a new deposition substrate is replaced, the distance D' between the deposition substrate plane and the hot wire assembly plane after the deposition substrate is replaced;

[0093] D' is calculated by formula 3 and formula 4;

[0094] Formula 3: θ=(1 / λ3*d3+1 / λ2*d2+1 / λ1*d1) / S;

[0095] θ'=(1 / λ3*d 30 +1 / λ2*d2'+1 / λ1*d1') / S;θ eff =θ / θ';

[0096] Formula 4: D'=D*(1 / θ eff ) 1 / 2 ;

[0097] The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition platform; d 30 is the thickness of the new deposited substrate; θ is the thermal resistance before the new deposited substrate is replaced; θ' is the thermal resistance after the new deposited substrate is replaced;

[0098] The upper surface area of ​​the deposition base, the upper surface area of ​​the deposition substrate, the lower surface area of ​​the deposition substrate, the upper surface area of ​​the first support block, the lower surface area of ​​the first support block, the upper surface area of ​​the second support block, the upper surface area of ​​the third support block, and the lower surface area of ​​the third support block are the same.

[0099] Specifically, the deposition base is composed of a deposition substrate, a first support block, and a second support block from top to bottom; the deposition substrate is 15 mm thick, the first support block is 5 mm thick, and the second support block is 10 mm thick; after deposition, due to high temperature deformation and surface carbides, the deposition substrate, the first support block, and the second support block are polished and leveled, and the deposition substrate is 14.8 mm thick after polishing, the first support block is 4.5 mm thick after polishing, and the second support block is 9.9 mm thick after polishing;

[0100] The surface temperature of the deposition substrate is 900°C, the outlet temperature of the cooling water is 50°C, the interface temperature between the second support block and the first support block is 150°C, and the interface temperature between the deposition substrate and the first support block is about 500°C; at the corresponding temperature, the thermal conductivities of the second support block, the first support block, and the deposition substrate are 390W / (m·K), 64W / (m·K), and 113W / (m·K), respectively.

[0101] Thermal resistance lost after grinding Δθ=0.00001352 / SK / W

[0102] Graphite is used for thermal resistance compensation, and the compensation thickness is d4=ΔθλS=0.00086m. The third support block is made of the same material as the first support block, and the thickness d4 is 0.86mm.

[0103] Embodiment 2:

[0104] The same contents as those in Example 1 are not described in detail here. The differences between this embodiment and Example 1 are as follows:

[0105] This embodiment provides a method for continuously preparing a HFCVD diamond film, further comprising:

[0106] The cooling medium in the cooling device is water, and the outlet water temperature of the cooling medium is 55°C;

[0107] Introducing hydrogen and methane in proportion to a target pressure; the introducing hydrogen and methane to a target pressure of 7000 Pa; the volume ratio of methane to hydrogen is 8:92;

[0108] The preset temperature of the upper surface of the deposition substrate is 998°C;

[0109] The cooling device was turned on, and the interface temperature between the deposition substrate and the first support block was 550°C; the interface temperature between the second support block and the first support block was 130°C.

[0110] Specifically, the deposition base is composed of a deposition substrate, a first support block, and a second support block from top to bottom; the deposition substrate is 20 mm thick, the first support block is 7.5 mm thick, and the second support block is 8 mm thick before grinding; after deposition, due to high temperature deformation and surface carbides, the deposition substrate, the first support block, and the second support block are ground flat, and the deposition substrate is 13.2 mm thick after grinding, the second support block is 7.2 mm thick after grinding, and the first support block is 6.8 mm thick after grinding;

[0111] The thickness of the deposited substrate after grinding is 13.2 mm. The thickness of the deposited substrate after grinding, d3', is less than 80% of the thickness of the deposited substrate, d3. A new deposited substrate needs to be replaced. The thickness of the new deposited substrate, d 30 17.5mm;

[0112] The surface temperature of the deposition substrate is 998°C, the outlet temperature of the cooling water is 55°C, the interface temperature between the second support block and the first support block is 130°C, and the interface temperature between the deposition substrate and the first support block is about 550°C; at the corresponding temperature, the thermal conductivity of the second support block, the first support block, and the deposition base are 395W / (m·K), 63W / (m·K), and 110W / (m·K), respectively;

[0113] θ=(1 / 395*0.008+1 / 63*0.0075+1 / 110*0.02) / S=0.0003925 / SK / W.

[0114] θ'=(1 / 395*0.0072+1 / 63*0.0068+1 / 110*0.0175) / S=0.0002853 / SK / W

[0115] D'=0.85D; D=7mm, D'=6mm.

[0116] Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for continuously preparing a HFCVD diamond film, characterized in that: The following steps are involved: Production of diamond films by hot wire production apparatus; The hot wire production device is provided with a deposition space, wherein the deposition space includes a hot wire assembly and a deposition base; The hot wire assembly comprises a plurality of hot wires arranged in parallel; The deposition base comprises a deposition substrate and a cooling platform, wherein the deposition substrate is placed on the upper surface of the cooling platform; The cooling platform comprises a first support block, a second support block, and a cooling device; the second support block and the first support block are sequentially placed above the cooling device; the deposition substrate is placed on the upper surface of the first support block; Measure the thickness d1 of the first support block, the thickness d2 of the second support block, and the thickness d3 of the deposition substrate; Measuring the distance D between the plane of the hot wire assembly and the plane of the deposition substrate; evacuating the deposition space; Introduce hydrogen and methane in proportion to the target pressure; Then, the hot wire is turned on to heat the upper surface of the deposition substrate to a preset temperature; When the thickness of the diamond film deposited on the surface of the deposition substrate reaches the preset requirement, the hot wire heating is turned off and the temperature is lowered; After the temperature is lowered, the hydrogen in the furnace is exhausted, and after the furnace is inflated to atmospheric pressure, the diamond film layer is removed from the surface of the deposition substrate to obtain the diamond film layer; Then, the hot wire production device is adjusted through the thermal structure compensation method of diamond deposition to produce a new batch of diamond films, thereby realizing continuous production of diamond films.

2. The HFCVD diamond film continuous preparation method according to claim 1, characterized in that: The hydrogen and methane are introduced to a target pressure of 2000-8000Pa.

3. The HFCVD diamond film continuous preparation method according to claim 1, characterized in that: The volume ratio of methane to hydrogen is (2-10):(90-98).

4. The HFCVD diamond film continuous preparation method according to claim 1, characterized in that: The preset temperature of the upper surface of the deposition substrate is 800-1000°C.

5. The method for continuously preparing HFCVD diamond film according to claim 1, characterized in that: The thermal structure compensation method for diamond deposition comprises the following steps: After the diamond film layer is removed from the surface of the deposition substrate, the upper surface and the lower surface of the first support block, the upper surface of the second support block, and the upper surface and the lower surface of the deposition substrate are polished and smoothed; Measure the thickness d1' of the first support block after grinding, the thickness d2' of the second support block after grinding, and the thickness d3' of the deposited substrate after grinding; The thickness d3' of the deposited substrate after grinding is judged, and when the thickness d3' of the deposited substrate after grinding meets the range of the deposited substrate, a third support block is added between the deposited substrate and the cooling device; When the thickness d3' of the deposited substrate after grinding does not meet the deposited substrate range, a new deposited substrate is replaced.

6. The method for continuously preparing HFCVD diamond film according to claim 5, characterized in that: When a third support block is added between the deposition substrate and the cooling device, the thickness d4 of the third support block is obtained by formula 1 and formula 2; Formula 1: Δθ=[1 / λ3*(d3-d3')+1 / λ2*(d2-d2')+1 / λ1*(d1-d1')] / S; Formula 2: d4=Δθ*λ4*S; The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition base; Δθ is the thermal resistance lost after grinding; λ4=λ1 or λ2.

7. The continuous preparation method of HFCVD diamond film according to claim 5, when a new deposition substrate is replaced, the distance D' between the deposition substrate plane and the hot wire assembly plane after the deposition substrate is replaced; D' is calculated by formula 3 and formula 4; Formula 3: θ=(1 / λ3*d3+1 / λ2*d2+1 / λ1*d1) / S; θ'=(1 / λ3*d 30 +1 / λ2*d2'+1 / λ1*d1') / S;θ eff =θ / θ'; Formula 4: D'=D*(1 / θ eff ) 1 / 2 ; The λ1 is the thermal conductivity of the first support block, λ2 is the thermal conductivity of the second support block, and λ3 is the thermal conductivity of the deposition substrate; S is the upper surface area of ​​the deposition platform; d 30 is the thickness of the new deposited substrate; θ is the thermal resistance before the new deposited substrate is replaced; θ' is the thermal resistance after the new deposited substrate is replaced.

8. The continuous preparation method of HFCVD diamond film according to claim 5, wherein the upper surface area of ​​the deposition base, the upper surface area of ​​the deposition substrate, the lower surface area of ​​the deposition substrate, the upper surface area of ​​the first support block, the lower surface area of ​​the first support block, the upper surface area of ​​the second support block, the upper surface area of ​​the third support block, and the lower surface area of ​​the third support block are the same.

9. The HFCVD diamond film continuous preparation method according to claim 1, wherein the temperature reduction device comprises a cooling medium storage container; The cooling medium storage container is provided with a liquid inlet and a liquid outlet, and the liquid inlet is connected to a cold source; The upper surface of the medium storage container is connected to the second supporting block.

10. The HFCVD diamond film continuous preparation method according to claim 1, wherein the material of the third support block is the same as the material of the first support block or the material of the second support block; The cooling medium in the cooling device is water, and the outlet water temperature of the cooling medium is 40-60°C; and / or The interface temperature between the deposition substrate and the first support block is 480-560°C; the interface temperature between the second support block and the first support block is 120-160°C.