Method for rapid delamination of polycrystalline diamond

Abstract

The application provides a polycrystalline diamond rapid stripping method and relates to the field of diamond thin film material preparation; the method comprises the following steps: pretreating a single crystal silicon substrate, wherein the pretreatment comprises ultrasonic cleaning and plasma treatment; mixing diamond micro powder and anhydrous ethanol to obtain a diamond micro powder solution, and performing centrifugal treatment on the diamond micro powder solution; rotating and coating the centrifuged diamond micro powder solution on a polishing surface of the single crystal silicon substrate for multiple times, wherein each coating process comprises at least three rotation parameter different rotation speed stages; placing the coated single crystal silicon substrate in a microwave plasma chemical vapor deposition device to grow polycrystalline diamond; and cutting the generated polycrystalline diamond film edge by using a laser to make the diamond film automatically strip from the substrate. The application can safely, efficiently and environmentally realize the rapid stripping of the polycrystalline diamond film, and solve the technical problems of danger, time consumption and pollution existing in the traditional chemical corrosion method.

Description

Technical Field

[0001] This invention relates to the field of diamond thin film material preparation, and more specifically, to a method for rapid exfoliation of polycrystalline diamond. Background Technology

[0002] When preparing polycrystalline diamond films using microwave plasma chemical vapor deposition (MPCVD), a single-crystal silicon wafer is typically used as the growth substrate. To obtain a self-supporting diamond film that can be used independently, the substrate must be removed.

[0003] Traditional mainstream methods use wet chemical etching to remove silicon substrates, such as using a mixture of hydrofluoric acid and nitric acid. This method has significant drawbacks: First, the chemical reagents used are highly toxic and corrosive, posing a serious threat to the health of operators and laboratory safety; second, the chemical etching process is slow, usually taking several days, resulting in low production efficiency; and finally, the disposal of waste acid raises environmental problems. Summary of the Invention

[0004] The purpose of this invention is to provide a rapid peeling method for polycrystalline diamond, which achieves complete peeling of the diamond film by forming a weak bonding interface between the substrate and the diamond growth layer, requiring only simple laser edge cutting, avoiding chemical corrosion steps, and making the peeling of polycrystalline diamond film efficient, safe and environmentally friendly.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for rapid exfoliation of polycrystalline diamond includes the following steps: The single-crystal silicon substrate is pretreated, wherein the pretreatment includes ultrasonic cleaning and plasma treatment; Diamond micro powder was mixed with anhydrous ethanol to obtain a diamond micro powder solution, and the diamond micro powder solution was centrifuged. The centrifuged diamond micro powder solution was spin-coated onto the polished surface of the single crystal silicon substrate multiple times, wherein each coating process included at least three rotation speed stages with different rotation parameters; The coated monocrystalline silicon substrate was placed in a microwave plasma chemical vapor deposition apparatus to grow polycrystalline diamond. A laser is used to cut along the edge of the generated polycrystalline diamond film, causing the diamond film to automatically peel off from the substrate.

[0006] Furthermore, the ultrasonic cleaning includes: performing ultrasonic cleaning on the single crystal silicon substrate 1-3 times in sequence with anhydrous ethanol and acetone, with each cleaning lasting 5-15 minutes.

[0007] Furthermore, the centrifugation speed is 1000-3000 rpm, the centrifugation time is 5-30 min, and the process is repeated 1-5 times.

[0008] Furthermore, the plasma treatment conditions are: power 1-3 kW, pressure 0.5-2 Torr, oxygen flow rate 100-300 sccm, and treatment time 5-30 min.

[0009] Furthermore, the spin coating process comprises three consecutive stages: First stage: rotational acceleration of 30-100 rpm / s, constant speed of 300-1000 rpm, and constant speed time of 5-20s; Second stage: rotational acceleration is 100-300 rpm / s, constant speed is 1000-2500 rpm, and constant speed time is 20-50s; The third stage: the rotational acceleration is 100-300 rpm / s, the constant speed is 2500-4000 rpm, and the constant speed time is 100-300s.

[0010] Furthermore, the growth conditions for the polycrystalline diamond include: Power 8-9 kW; Pressure 130-150 Torr; Hydrogen flow rate 300-500 sccm; methane concentration 1%-3%; oxygen flow rate 0.1-1 sccm; nitrogen flow rate 0.1-1 sccm; The temperature in the central region of the substrate is 850-950℃, the temperature in the edge region is 800-900℃, and the growth time is 50-100h.

[0011] Furthermore, it also includes pre-treating the working cavity of the microwave plasma chemical vapor deposition equipment before polycrystalline diamond growth. The pre-treatment conditions are: power 8-9 kW, pressure 130-160 Torr, hydrogen 300-500 sccm, oxygen 3-5 sccm, substrate stage temperature 500-600℃, and etching time 3-6 hours.

[0012] Furthermore, after the single-crystal silicon substrate is introduced into the working cavity of the microwave plasma chemical vapor deposition equipment, a vacuum check step is also included: confirming that the pressure rise rate of the working cavity is ≤2 Pa / h.

[0013] Furthermore, the step of placing the coated single-crystal silicon substrate in a microwave plasma chemical vapor deposition apparatus for polycrystalline diamond growth further includes: After growth, the polycrystalline diamond is cooled down, including stopping the introduction of all process gases except hydrogen, maintaining a hydrogen environment for 30-60 minutes, and then cooling down for 0.5-1 hour.

[0014] The present invention has at least the following advantages or beneficial effects: This invention utilizes ultrasonic cleaning and plasma treatment to pretreat monocrystalline silicon substrates, effectively removing organic contaminants and particulate impurities from the substrate surface and obtaining a highly clean and activated surface. This provides an ideal substrate for subsequent uniform coating, and the activated surface can form a moderate rather than excessive bond with diamond micropowder, providing a basic starting point for constructing a weakly bonded interface. Centrifugation of the diamond micropowder solution effectively separates and removes large-sized micropowder particles formed by agglomeration, resulting in a suspension with uniform particle size distribution and good dispersion. This ensures the successful nucleation of diamond particles ultimately coated on the substrate. Uniform particle size avoids stress concentration or abnormally strong adhesion points caused by large local particles, ensuring a large-area uniform weak bonding interface. Multiple spin coatings, each with at least three rotational speed stages with different parameters, allow for precise control of the diamond powder deposition process on the substrate surface. Multi-stage spin coating enables controllable arrangement of the powder solution, first spreading, then thinning, and finally densifying, forming a uniform, dense, and complete initial nucleation layer. This nucleation layer, acting as a growth template, directly determines the bonding characteristics of the subsequent diamond growth interface and is the core structural basis for achieving peelability. Placing the coated substrate in an MPCVD device for polycrystalline diamond growth allows for direct epitaxial growth in an optimized process atmosphere based on the aforementioned high-quality nucleation layer, ultimately forming the desired weak bonding interface between the grown diamond film and the substrate. Finally, laser cutting along the edge of the polycrystalline diamond film allows for automatic peeling of the diamond film from the substrate, utilizing the high precision and localized high heat energy of laser processing to efficiently sever the edge bonding area. Since the aforementioned process has pre-constructed an integral weak bonding interface, the minute thermal and mechanical stresses generated by laser cutting are sufficient to overcome the adhesion of this interface, thereby achieving safe, rapid, and complete physical peeling of the diamond film. This replaces the dangerous, time-consuming, and environmentally polluting chemical etching method, enabling safe, efficient, and environmentally friendly rapid peeling of polycrystalline diamond films, fundamentally solving the technical problems of danger, time consumption, and pollution associated with traditional chemical etching methods. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic flowchart of the rapid peeling method for polycrystalline diamond provided in the application embodiment; Figure 2This is a schematic diagram of the polycrystalline diamond film after cutting in Example 1 of the application; Figure 3 This is a schematic diagram of the polycrystalline diamond film after cutting, which is the comparative example 1. Detailed Implementation

[0017] Example

[0018] Please refer to Figure 1 The figure shows a flowchart of the rapid peeling method for polycrystalline diamond in an embodiment of the present invention. This embodiment provides a rapid peeling method for polycrystalline diamond. This method, without damaging the polished surface of the substrate, simultaneously forms a weak bonding interface between the substrate and the growth layer, reducing the adhesion between the growth layer and the substrate. This allows the polycrystalline diamond to be peeled off using only laser cutting, completely avoiding the chemical etching step. The method mainly includes the following steps: S110. Pre-treat the single-crystal silicon substrate, wherein the pre-treatment includes ultrasonic cleaning and plasma treatment; S120. Diamond micro powder is mixed with anhydrous ethanol to obtain a diamond micro powder solution, and the diamond micro powder solution is centrifuged. S130. The centrifuged diamond micro powder solution is spin-coated onto the polished surface of the single crystal silicon substrate multiple times, wherein each coating process includes at least three rotation speed stages with different rotation parameters. S140. Place the coated single-crystal silicon substrate in a microwave plasma chemical vapor deposition apparatus to grow polycrystalline diamond. S150: A laser is used to cut along the edge of the generated polycrystalline diamond film, so that the diamond film is automatically peeled off from the substrate.

[0019] In one embodiment of the present invention, the specific process of "pre-treating the single-crystal silicon substrate, wherein the pre-treatment includes ultrasonic cleaning and plasma treatment" in step S110 can be further described in conjunction with the following description.

[0020] The monocrystalline silicon substrate undergoes pretreatment including ultrasonic cleaning and plasma treatment. Ultrasonic cleaning aims to remove organic contaminants and particulate impurities from the substrate surface, providing a clean surface for subsequent processing. Preferably, RPS plasma treatment is used to further clean and activate the substrate surface, remove extremely fine particles, and enhance surface energy. This allows for the uniform and stable adhesion of subsequently coated diamond powder, while preventing the formation of overly strong chemical bonds—a crucial first step in controlling the formation of a weak bonding interface.

[0021] As an example, the ultrasonic cleaning described above specifically includes performing ultrasonic cleaning on the monocrystalline silicon substrate 1-3 times in sequence with anhydrous ethanol and acetone, with each cleaning lasting 5-15 minutes, to ensure thorough removal of contaminants of different polarities.

[0022] The plasma treatment conditions described above are: power 1-3 kW, pressure 0.5-2 Torr, oxygen flow rate 100-300 sccm, and treatment time 5-30 min. By treating the surface for 5-30 minutes under specific power, pressure, and oxygen atmosphere conditions, the surface can be effectively cleaned and activated, forming an interface state conducive to weak bonding.

[0023] In one embodiment of the present invention, the specific process of step S120, "mixing diamond micro powder with anhydrous ethanol to obtain a diamond micro powder solution and centrifuging the diamond micro powder solution," can be further described in conjunction with the following description.

[0024] First, take 20-150 ml of anhydrous ethanol and 1 ct of diamond micropowder, and mix the diamond micropowder with the anhydrous ethanol to prepare a diamond micropowder solution. Then, centrifuge the diamond micropowder solution. Centrifugation effectively separates large particles formed by agglomeration in the solution, obtaining a uniformly dispersed micropowder suspension with uniform particle size. This ensures that the micropowder size is uniform when coated onto the substrate in subsequent steps, avoiding local stress concentration or excessive bonding caused by large particles, which is the basis for achieving large-area uniform weak bonding.

[0025] As an example, the centrifugation conditions described above are: rotation speed of 1000-3000 rpm, centrifugation time of 5-30 min, repeated 1-5 times.

[0026] In one embodiment of the present invention, the specific process of step S130, "coating the centrifuged diamond micro powder solution onto the polished surface of the single crystal silicon substrate in multiple rotational stages, wherein each coating process includes at least three rotational speed stages with different rotational parameters," can be further described in conjunction with the following description.

[0027] The centrifuged solution is spin-coated onto the pretreated polished substrate surface 3-5 times, with each coating process including at least three stages with different rotation parameters.

[0028] As an example, the process involves three stages: Stage 1: Rotational acceleration of 30-100 rpm / s, uniform rotation speed of 300-1000 rpm, and uniform rotation time of 5-20 s. Its main function is to initially and uniformly spread the solution. Stage 2: Rotational acceleration of 100-300 rpm / s, uniform rotation speed of 1000-2500 rpm, and uniform rotation time of 20-50 s. This stage aims to remove excess solution through higher rotation speeds and control film thickness. Stage 3: Rotational acceleration of 100-300 rpm / s, uniform rotation speed of 2500-4000 rpm, and uniform rotation time of 100-300 s. Utilizing high rotation speeds and longer time, this stage ensures the micropowders achieve the densest and most uniform arrangement on the substrate surface and allows the solvent to completely evaporate. Through multi-stage precision spin coating, a high-quality nucleation layer with uniform thickness and controllable adhesion can be formed on the substrate. This layer serves as the initial template for the weak bonding interfaces in subsequent growth.

[0029] In one embodiment of the present invention, the specific process of step S140, "placing the coated single-crystal silicon substrate in a microwave plasma chemical vapor deposition apparatus to grow polycrystalline diamond," can be further described in conjunction with the following description.

[0030] The coated single-crystal silicon substrate was placed in an MPCVD machine for direct polycrystalline diamond growth. Optimized growth conditions were: power 8-9 kW, pressure 130-150 Torr, hydrogen 300-500 sccm, methane concentration 1%-3%, and trace amounts of oxygen (0.1-1 sccm) and nitrogen (0.1-1 sccm). The lower methane concentration (compared to the 3%-5% or higher commonly used in traditional nucleation stages) and trace amounts of oxygen gas aimed to achieve a mild growth initiation. This avoided violent silicon carbide reactions or excessive welding between the microparticles and the silicon substrate due to carbon source supersaturation in the early stages of growth, thus maintaining the weak bonding characteristics of the interface. Simultaneously, the temperature in the central region of the substrate was 850-950℃, and the temperature in the edge region was 800-900℃, with a growth time of 50-100 hours. This precisely controlled temperature gradient ensured uniform film growth and internal stress distribution, which is beneficial for subsequent peeling.

[0031] In one embodiment of the present invention, the specific process of step S150, "using a laser to cut along the edge of the generated polycrystalline diamond film, so that the diamond film is automatically peeled off from the substrate," can be further described in conjunction with the following description.

[0032] After growth is complete, a laser is used to cut along the edge of the diamond film. Since the aforementioned process has pre-set a weak bonding state at the interface, the thermal effect and mechanical stress generated by laser cutting are sufficient to overcome the interfacial adhesion, allowing the diamond film to be automatically or with slight external force completely peeled off from the substrate, achieving film-peeling separation. The process takes only a few minutes and is safe and efficient.

[0033] In one embodiment of the present invention, to ensure the purity and repeatability of the growth process, the working cavity of the MPCVD equipment can be pretreated before diamond growth. The pretreatment conditions are: power 8-9 kW, pressure 130-160 Torr, hydrogen 300-500 sccm, oxygen 3-5 sccm, substrate stage temperature 500-600℃, and etching time 3-6 hours. That is, the cavity is etched at high temperature for 3-6 hours under a hydrogen and a small amount of oxygen atmosphere at high power and pressure to remove any contaminants that may be present on the inner wall of the cavity.

[0034] Furthermore, after the substrate is introduced into the reaction chamber, a vacuum check is performed on the equipment to ensure that the working chamber pressure rise rate is ≤2 Pa / h, in order to eliminate the impact of gas leakage on process stability.

[0035] In one embodiment of the present invention, after growth is completed and before laser cutting, a cooling process is performed. Specifically, all process gases except hydrogen are turned off, and a pure hydrogen environment is maintained for 30-60 minutes to stabilize the grown surface. Subsequently, the substrate is cooled to room temperature within 0.5-1 hour. This step helps to release some thermal stress and relax the diamond film structure, resulting in more uniform stress on the film layer and more complete and straight peeling during subsequent laser cutting.

[0036] The method described in this invention forms a high-quality nucleation layer through plasma cleaning combined with precision spin coating. Combined with a low-methane initiation growth process design, it successfully constructs a weakly bonded interface with optimal adhesion between the silicon substrate and the diamond film. The entire process avoids the use of any strong acids or alkalis, and the peeling process is transformed from traditional chemical etching that takes several days to laser cutting that takes only minutes. While achieving efficient and rapid peeling, it significantly improves operational safety, reduces environmental pollution and processing costs, and has significant industrial application value.

[0037] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and a specific example. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0038] Example 1

[0039] A method for rapid peeling of polycrystalline diamond includes the following steps: Substrate preparation: A 3-inch, 3mm thick, P-type single-crystal silicon wafer was selected as the substrate.

[0040] Substrate cleaning: The single crystal silicon wafer is ultrasonically cleaned twice in anhydrous ethanol for 10 minutes each time; then ultrasonically cleaned twice in acetone for 10 minutes each time. After completion, it is dried with high-purity nitrogen.

[0041] Plasma treatment: The cleaned silicon wafer is placed in a reactive ion etching (RPS) device, the power is set to 2kW, the pressure is 1 Torr, oxygen is introduced at 200 sccm, and the treatment time is 15min.

[0042] Preparation and treatment of the micronized solution: Weigh 1 carat (ct) W5 grade diamond micronized powder and add it to 100 ml of anhydrous ethanol, stirring to form a suspension. Centrifuge the suspension at 2000 rpm for 15 min, discard the small amount of precipitate at the bottom of the supernatant, and take the homogeneous suspension from the middle and upper parts. Repeat this centrifugation process twice.

[0043] Spin coating: The treated silicon wafer is fixed on a spin coater, and the centrifuged micro-powder solution is added dropwise. Three coating processes are performed, each consisting of three stages: Stage 1: Spin acceleration of 50 rpm / s, accelerating to a constant speed of 500 rpm, held for 10 seconds; Stage 2: Spin acceleration of 200 rpm / s, accelerating to a constant speed of 1500 rpm, held for 30 seconds; Stage 3: Spin acceleration of 200 rpm / s, accelerating to a constant speed of 3000 rpm, held for 200 seconds. After coating, the wafer is dried on an 80°C hot plate.

[0044] Equipment Preparation: First, pre-treat the substrate stage: Apply a brushed cloth to the working and heat dissipation surfaces, ensuring no surface damage. Perform ultrasonic cleaning once with anhydrous ethanol for 10 minutes, then wipe the working surface with acetone until clean and free of foreign matter. Next, pre-treat the working chamber of the MPCVD equipment: Insert the cleaned substrate stage, close the chamber, evacuate, and then introduce hydrogen at 400 sccm and oxygen at 4 sccm. Set the microwave power to 8.5 kW and the pressure to 145 Torr, heating the substrate stage to 550℃ and maintaining the etching temperature for 4 hours. After etching, remove the substrate stage, place the coated silicon wafer on it, and reinstall it into the working chamber. Evacuate to e -3 The pressure rise was below 1.5 Pa / h, and the chamber pressure rise rate was confirmed to be stable at 1.5 Pa / h.

[0045] Substrate heating: Introduce hydrogen gas, start the microwave, and raise the substrate temperature to above 700°C within 20 minutes.

[0046] Polycrystalline diamond growth: The process gas was adjusted to a stable state: power 8.5 kW, pressure 140 Torr, hydrogen flow rate 400 sccm, methane concentration 2%, oxygen flow rate 0.5 sccm, and nitrogen flow rate 0.5 sccm. Infrared thermography was used to control the substrate temperature at the center to approximately 900℃ and at the edge to approximately 850℃. Growth was continued under these conditions for 80 hours.

[0047] Cooling: After growth is complete, close the methane, oxygen, and nitrogen inlet valves, and maintain a constant hydrogen flow rate for 30 minutes. Then, gradually reduce the microwave power and pressure, and cool the substrate to room temperature within 45 minutes.

[0048] Laser cutting and peeling: The sample with the grown diamond film is removed, and a green laser is used to cut along the outer edge of the diamond film approximately 1 mm. After the cut penetrates the diamond film, due to the weak interfacial bonding, the diamond film automatically warps and separates from the silicon substrate under its own stress, such as... Figure 2 As shown. The entire stripping process requires no chemical corrosion, making it safe and quick.

[0049] Example 2

[0050] It is basically the same as Example 1, except that: Change the centrifugation speed to 1500 rpm and the centrifugation time to 25 min, and repeat 3 times.

[0051] The spin coating parameters were adjusted as follows: First stage: accelerate from 80 rpm to 800 rpm and hold for 15 seconds; Second stage: accelerate from 250 rpm to 2000 rpm and hold for 40 seconds; Third stage: accelerate from 250 rpm to 3500 rpm and hold for 250 seconds.

[0052] The growth conditions for polycrystalline diamond were adjusted to: methane concentration 1.5% and growth time 100h.

[0053] Using the same laser cutting method, the diamond film can also be automatically peeled off with good results.

[0054] Comparative Example 1 Using traditional methods: The substrate pretreatment uses diamond micron powder to mechanically grind the silicon wafer surface instead of plasma treatment: diamond emulsion (1 ct of diamond micron powder to 50 ml of anhydrous ethanol) is sprayed onto the polished surface of the silicon wafer, the suction cup is wrapped with a lint-free cloth, and the wafer is ground clockwise or counterclockwise for 20 minutes. The ground silicon wafer is then rinsed and wiped clean with deionized water, and then ultrasonically cleaned twice with anhydrous ethanol for 10 minutes each time, and then ultrasonically cleaned twice with acetone for 10 minutes each time.

[0055] Before MPCVD growth, an independent nucleation step is added: under similar pressure and temperature, 4% methane is introduced for nucleation for 30 minutes.

[0056] The subsequent growth and cooling steps are the same as in Example 1.

[0057] After laser cutting, the diamond film adheres firmly to the substrate and cannot detach automatically, such as Figure 3As shown. To obtain a self-supporting film, a mixture of hydrofluoric acid and nitric acid is still needed to etch and remove the silicon substrate, a dangerous process that takes several days.

[0058] By comparing Examples 1 and 2 with Comparative Example 1, the present invention fully verifies that the specific combination of pretreatment and growth processes forms a weak bonding state at the interface, which is the key to achieving rapid laser ablation. This method has the outstanding advantages of high efficiency, safety and environmental protection.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid peeling of polycrystalline diamond, characterized in that, Includes the following steps: The single-crystal silicon substrate is pretreated, wherein the pretreatment includes ultrasonic cleaning and plasma treatment; Diamond micro powder was mixed with anhydrous ethanol to obtain a diamond micro powder solution, and the diamond micro powder solution was centrifuged. The centrifuged diamond micro powder solution was spin-coated onto the polished surface of the single crystal silicon substrate multiple times, wherein each coating process included at least three rotation speed stages with different rotation parameters; The coated single-crystal silicon substrate was placed in a microwave plasma chemical vapor deposition equipment to grow polycrystalline diamond. A laser is used to cut along the edge of the generated polycrystalline diamond film, causing the diamond film to automatically peel off from the substrate.

2. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The ultrasonic cleaning process includes performing ultrasonic cleaning on the monocrystalline silicon substrate 1-3 times in sequence with anhydrous ethanol and acetone, with each cleaning session lasting 5-15 minutes.

3. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The centrifugation process is carried out at a speed of 1000-3000 rpm for 5-30 min, and is repeated 1-5 times.

4. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The plasma treatment conditions are: power 1-3 kW, pressure 0.5-2 Torr, oxygen flow rate 100-300 sccm, and treatment time 5-30 min.

5. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The spin coating process comprises three consecutive stages: First stage: rotational acceleration of 30-100 rpm / s, constant speed of 300-1000 rpm, and constant speed time of 5-20s; Second stage: rotational acceleration is 100-300 rpm / s, constant speed is 1000-2500 rpm, and constant speed time is 20-50s; The third stage: the rotational acceleration is 100-300 rpm / s, the constant speed is 2500-4000 rpm, and the constant speed time is 100-300s.

6. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The growth conditions for the polycrystalline diamond include: Power 8-9 kW; Pressure 130-150 Torr; Hydrogen flow rate 300-500 sccm; methane concentration 1%-3%; oxygen flow rate 0.1-1 sccm; nitrogen flow rate 0.1-1 sccm; The temperature in the central region of the substrate is 850-950℃, the temperature in the edge region is 800-900℃, and the growth time is 50-100h.

7. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, It also includes pretreatment of the working cavity of the microwave plasma chemical vapor deposition equipment before polycrystalline diamond growth. The pretreatment conditions are: power 8-9kW, pressure 130-160 Torr, hydrogen 300-500 sccm, oxygen 3-5 sccm, substrate stage temperature 500-600℃, and etching time 3-6 hours.

8. The rapid peeling method for polycrystalline diamond according to claim 1 or 7, characterized in that, After the single-crystal silicon substrate is introduced into the working cavity of the microwave plasma chemical vapor deposition equipment, the equipment vacuum check step is also included: confirming that the pressure rise rate of the working cavity is ≤2 Pa / h.

9. The rapid peeling method for polycrystalline diamond according to claim 1, characterized in that, The step of placing the coated monocrystalline silicon substrate in a microwave plasma chemical vapor deposition apparatus for polycrystalline diamond growth further includes: After growth, the polycrystalline diamond is cooled down, including stopping the introduction of all process gases except hydrogen, maintaining a hydrogen environment for 30-60 minutes, and then cooling down for 0.5-1 hour.

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