Diamond film growth heat dissipation substrate for high-power microwave plasma equipment and application of diamond film growth heat dissipation substrate

Abstract

The invention discloses a diamond film growth heat dissipation substrate for high-power microwave plasma equipment and application of the diamond film growth heat dissipation substrate. One or more sample holes for placing samples are formed in the top surface of the diamond film growth heat dissipation substrate, so that the diamond film growth heat dissipation substrate has the advantages of good heat dissipation performance, high deformation resistance and the like, and the problems of non-uniform temperature field and the like in a microwave plasma dispersion and adsorption process are solved.

Description

Technical Field

[0001] This invention relates to the field of high-power microwave plasma equipment, and more specifically to a diamond film growth heat dissipation substrate for high-power microwave plasma equipment and its application. Background Technology

[0002] Diamond films possess extremely high hardness, excellent thermal conductivity, good chemical stability, and outstanding electrical properties, making them widely applicable in numerous fields such as electronics, optics, and mechanics. With technological advancements, the use of high-power microwave plasma equipment (such as 915MHz-75KW level) to grow large-area, large-size diamond films has become a trend, which places stringent requirements on the heat dissipation substrate during the growth process.

[0003] For example, the patent specification with publication number CN113481595A discloses a 915MHz microwave plasma chemical vapor deposition device for an M-shaped coaxial antenna, which is mainly used to prepare single-crystal diamond and polycrystalline diamond films and can achieve high-efficiency deposition of single plasma under high power and high or low cavity pressure.

[0004] For example, the patent specification with publication number CN120844062A discloses a 915 MHz microwave plasma chemical vapor deposition (MPCVD) device for depositing 16-inch diamond wafers.

[0005] In the existing technology, there are many problems with the diamond film growth substrate used in microwave plasma equipment: on the one hand, the heat dissipation performance of the substrate is poor, which makes it easy for heat to concentrate during the growth process, resulting in uneven temperature field distribution, affecting the matching stability of plasma density and electric field, and thus reducing the growth quality and yield of diamond film; on the other hand, traditional substrates are prone to deformation under high power and high temperature environment, which not only affects the placement stability of the sample, but may also damage the sample due to the thermal stress generated by the deformation, and will also affect the dispersion and adsorption effect of microwave plasma, further restricting the preparation of large-area, large-size high-quality diamond films.

[0006] Therefore, a diamond film growth heat dissipation substrate suitable for high-power microwave plasma equipment such as 75KW is proposed to solve the aforementioned problems. Summary of the Invention

[0007] This invention provides a diamond film growth heat dissipation substrate for high-power microwave plasma equipment and its application. It has the advantages of good heat dissipation performance and strong deformation resistance, and solves the problem of uneven temperature field during the high-density, high-quality, large-size growth, dispersion and adsorption process of microwave plasma stable matching discharge.

[0008] The specific technical solution is as follows: In a first aspect, the present invention provides a diamond film growth heat dissipation substrate for a high-power microwave plasma device, wherein the top surface of the diamond film growth heat dissipation substrate has one or more sample holes for placing samples.

[0009] Furthermore, in this invention, high-power microwave plasma equipment refers to microwave plasma equipment with a power of not less than 10KW, such as 915MHz-75KW high-power microwave plasma equipment, etc.

[0010] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has one or more sample holes of different sizes.

[0011] In some preferred embodiments, the aperture of the sample aperture is 2 inches or larger. The diamond film growth heat dissipation substrate of the present invention is particularly suitable for growing diamond films on large-sized samples (e.g., 2 inches or larger), and the grown diamond films are of very high quality.

[0012] In some preferred embodiments, the diamond film growth heat dissipation substrate is cylindrical. More preferably, the diameter of the diamond film growth heat dissipation substrate is 100-400 mm, such as 290 mm, 300 mm, 310 mm, 350 mm, etc., with reasonable size settings to adapt to equipment requirements.

[0013] In some preferred embodiments, the thickness of the diamond film growth heat dissipation substrate is 2-20 mm, such as 5 mm, 10 mm, 15 mm, etc., with reasonable size settings to adapt to equipment requirements.

[0014] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate is smooth, and the edges of the smooth surface are chamfered. The chamfering of the smooth surface edges effectively avoids discharge phenomena during the experiment, ensuring the smooth progress of the experiment. More preferably, the chamfering is a transition arc with a 45° angle and a radius of 1-5 mm.

[0015] In some preferred embodiments, when the sample is placed in the sample hole, the top surface of the sample is not higher than the top surface of the diamond film growth heat dissipation substrate, that is, the top surface of the sample is lower than the top surface of the diamond film growth heat dissipation substrate, or the top surface of the sample is at the same height as the top surface of the diamond film growth heat dissipation substrate.

[0016] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has two or more sample holes, and the closest distance between the edges of two adjacent sample holes is not less than 3 mm, which is beneficial for heat dissipation and ensures the quality of the diamond film grown on the top surface of each sample.

[0017] The diamond film growth heat dissipation substrate of the present invention can simultaneously grow diamond films on multiple samples at one time, significantly improving production efficiency while ensuring very high quality of the diamond films. In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has more than five sample holes.

[0018] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has five 4-inch sample holes and one 2-inch sample hole, wherein: the diameter of the 4-inch sample holes is 101.6-109.6 mm, preferably greater than 101.6 mm and not greater than 109.6 mm; the diameter of the 2-inch sample hole is 50.8-58.8 mm, preferably greater than 50.8 mm and not greater than 58.8 mm. More preferably, the five 4-inch sample holes are evenly distributed around the periphery of the 2-inch sample hole.

[0019] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has six 3-inch sample holes and one 2-inch or 4-inch sample hole, wherein: the diameter of the 3-inch sample hole is 76.2-84.2 mm, preferably greater than 76.2 mm and not greater than 84.2 mm; the diameter of the 2-inch sample hole is 50.8-58.8 mm, preferably greater than 50.8 mm and not greater than 58.8 mm; and the diameter of the 4-inch sample hole is 101.6-109.6 mm, preferably greater than 101.6 mm and not greater than 109.6 mm. More preferably, the six 3-inch sample holes are evenly distributed around the periphery of the 2-inch or 4-inch sample hole.

[0020] In some preferred embodiments, the top surface of the diamond film growth heat dissipation substrate has 15 2-inch sample holes, the diameter of which is 50.8-58.8 mm, preferably greater than 50.8 mm and not greater than 58.8 mm. More preferably, the 15 2-inch sample holes are distributed in two layers: an inner layer of 5 2-inch sample holes evenly distributed on the same circumference, and an outer layer of 10 2-inch sample holes evenly distributed around the inner layer.

[0021] Furthermore, the material of the heat dissipation substrate for diamond film growth includes one or more of silicon, quartz, copper, and molybdenum, preferably molybdenum. The good thermal conductivity and high temperature resistance of molybdenum provide a stable basic environment for diamond film growth.

[0022] In some preferred embodiments, the thermal conductivity of the diamond film growth heat dissipation substrate at room temperature is ≥130 W / (m·K), and the coefficient of thermal expansion at 800-1200℃ is ≤5.5×10⁻⁶. -6 / ℃.

[0023] In a second aspect, the present invention provides the application of the diamond film growth heat dissipation substrate described in the first aspect for the high-power microwave plasma growth of diamond films on samples.

[0024] In some preferred embodiments, the diamond film growth heat dissipation substrate undergoes a pretreatment annealing operation before being used for high-power microwave plasma growth of the diamond film on the sample. This pretreatment annealing operation includes: introducing hydrogen and oxygen, and etching under 30-50 kW plasma power and 10-20 kPa pressure conditions. The pretreatment annealing operation can remove oil stains and debris generated during the surface processing of the diamond film growth heat dissipation substrate, and enhance the substrate's toughness during high-temperature experiments.

[0025] In some preferred embodiments, the volume ratio of hydrogen to oxygen in the pretreatment annealing operation is 300-500:1.

[0026] In some preferred embodiments, the etching time in the pretreatment annealing operation is 10-20 hours.

[0027] Thirdly, the present invention provides a high-power microwave plasma device, including the diamond film growth heat dissipation substrate described in the first aspect.

[0028] It is understood that the high-power microwave plasma equipment has the necessary components to realize its basic functions (such as MPCVD, etc.). These components may include microwave transmission system, microwave coupling system, mode converter, plasma working chamber, vacuum measurement system, gas flow MFC (mass flow meter) system, temperature measurement and monitoring system, cooling water system, PLC control system, etc., all of which can adopt known existing technologies.

[0029] Compared with the prior art, the beneficial effects of this invention are as follows: The substrate of this invention can be designed with various aperture schemes to meet the placement requirements of samples of different sizes, thereby improving the versatility and practicality of the substrate.

[0030] The substrate of this invention reduces deformation in high-power experiments, providing a certain degree of protection for the sample and dispersing and releasing some thermal stress, thereby improving experimental quality and diamond film yield, and creating favorable conditions for the deposition of large-area, large-size, high-quality diamond coatings. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the heat dissipation substrate structure in Embodiment 1 of the present invention.

[0032] Figure 2 This is a photograph of the experimental results of the heat dissipation substrate in Embodiment 1 of the present invention.

[0033] Figure 3This is a schematic diagram of the heat dissipation substrate structure in Embodiment 2 of the present invention.

[0034] Figure 4 This is a schematic diagram of the heat dissipation substrate structure in Embodiment 3 of the present invention.

[0035] Figure 5 This is a photograph of the heat dissipation substrate used in the comparative experiment of Embodiment 4 of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0037] Unless otherwise specified, the operating methods in the following examples are generally performed under conventional conditions or as suggested.

[0038] Example 1: This embodiment provides a heat-dissipating molybdenum substrate for diamond film growth in a 75KW microwave plasma device. It is a dedicated substrate designed for experimental scenarios that require the simultaneous growth of five 4-inch and one 2-inch diamond film samples.

[0039] See Figure 1 The substrate 1 is cylindrical with a smooth top surface. Five 4-inch sample holes and one 2-inch sample hole are located on the top surface, with the five 4-inch sample holes evenly distributed around the 2-inch sample hole. When the sample is placed inside the sample hole, the top surface of the sample is at the same height as the top surface of the diamond film growth and heat dissipation molybdenum substrate.

[0040] In terms of material selection, the substrate 1 is made of high-purity molybdenum material with a purity of 99.95%, and its coefficient of thermal expansion at 800-1200℃ is ≤5.5×10. -6 / ℃; This purity of molybdenum material has extremely low impurity content, which can effectively prevent impurities from volatilizing or reacting adversely with reactive gases in the high-temperature plasma environment, thereby reducing interference with the diamond film growth process and ensuring the purity and structural integrity of the film layer; at the same time, high-purity molybdenum material has excellent thermal conductivity (approximately 138 W / (m·K) at room temperature) and high-temperature stability (melting point up to 2623℃), and can maintain stable physical properties in the high-temperature environment (usually 800-1200℃) generated by 75KW microwave plasma equipment, providing a reliable carrier for heat conduction and diffusion.

[0041] The diameter of substrate 1 in this experiment is set to 310 mm and the thickness to 5 mm. The diameter of 310 mm can be adapted to the reaction cavity size of the 915 MHz-75 KW microwave plasma equipment, ensuring that the substrate has a suitable installation space in the equipment, while providing sufficient distribution area for five 4-inch and one 2-inch samples, avoiding heat interference between samples due to excessive proximity. The thickness of 5 mm ensures the structural strength of the substrate while taking into account the heat conduction efficiency. The thinner thickness can reduce the heat conduction resistance inside the substrate, allowing heat to diffuse more quickly from the sample growth area to the edge of the substrate, reducing the risk of local overheating.

[0042] To enhance experimental safety, the smooth edges of substrate 1 underwent a fine chamfering process; specifically, a 45° angled, 1mm radius arc transition was used. This process effectively eliminates sharp edges and prevents local discharge caused by concentrated electric field intensity at the edges during microwave plasma excitation. Experimental data shows that the chamfered substrate, when operating at 75KW power, reduced the discharge rate to below 0.1%, significantly improving the stability and safety of the experimental process.

[0043] In terms of sample placement structure design, six sample placement holes are provided on substrate 1; five of them are 4-inch sample holes with a diameter precisely controlled at 101.6 mm, which matches the standard 4-inch sample and ensures that the sample can be placed stably; the other is a 2-inch sample hole with a diameter of 50.8 mm, which matches the standard 2-inch sample and ensures the stability of sample placement; the distribution of the six holes adopts a central symmetric design, and is arranged radially and uniformly with the center of the substrate as the center. This layout can make the energy distribution of each sample in the plasma environment more uniform and reduce the deviation in film growth quality caused by position differences.

[0044] When this substrate was used to grow diamond films in a 915MHz-75KW microwave plasma device, the specific experimental procedure was as follows: First, 3000 sccm of hydrogen and 10 sccm of oxygen were introduced, and the substrate was etched and annealed for 20 hours under a plasma power of 50KW and a gas pressure of 20KPa. In the next step, five 4-inch and one 2-inch substrates (samples) after pretreatment were placed into their respective sample holes, ensuring that the substrate surface was flush with the substrate surface. Then, the substrate was mounted on the sample stage of the device, and the distance from the water-cooled stage, heat dissipation substrate, and microwave plasma was adjusted to maintain a suitable height according to actual needs. Next, the vacuum chamber pressure was evacuated to below 0.1Pa, and a mixture of hydrogen and methane (volume ratio of 3000:60) was introduced to control the chamber pressure at 20KPa. Finally, the microwave power supply was turned on, the plasma power was adjusted to 50KW, and stable operation was maintained for 20 hours.

[0045] Experimental results show that the substrate can effectively disperse heat, maintain a uniform temperature field on the surface of each sample, ensure the stability of the matching between plasma density and electric field, and maintain stable plasma morphology without significant displacement, arcing, or flashing. Simultaneously, due to the effective dispersion of thermal stress, the grown diamond film has a smooth surface without cracks or warping. Figure 2 The experimental results are clearly visible; Raman spectroscopy analysis shows that the sp... 3 With a bond content of over 99%, all performance indicators meet the standards of high-quality diamond films.

[0046] Example 2: This embodiment is a heat-dissipating molybdenum substrate for diamond film growth, mainly designed for experimental needs that require the simultaneous growth of six 3-inch and one 4-inch diamond film samples, and is suitable for comparative experimental scenarios with multiple sample sizes.

[0047] See Figure 3 The substrate 1 is cylindrical with a smooth top surface. Six 3-inch sample holes and one 4-inch sample hole are located on the top surface, with the six 3-inch sample holes evenly distributed around the 4-inch sample hole. When the sample is placed inside the sample hole, the top surface of the sample is at the same height as the top surface of the diamond film growth and heat dissipation molybdenum substrate.

[0048] In terms of material selection, substrate 1 uses the same high-purity molybdenum material with a purity of 99.95% as in Example 1, to ensure the material's high thermal conductivity and high-temperature stability, providing consistent substrate conditions for the synchronous growth of samples of different sizes.

[0049] In terms of dimensions, the diameter of substrate 1 is set at 310 mm and the thickness at 5 mm. The 310 mm diameter provides more space for sample placement and is compatible with the size of the reaction chamber of the device, ensuring uniform plasma coverage on the substrate surface. At the same time, it can still maintain good thermal conductivity.

[0050] The smooth edge of substrate 1 is also chamfered, using the same 45° angle and 1mm radius arc transition as in Example 1, which effectively prevents discharge during the experiment and ensures the safe and stable operation of the experiment.

[0051] Regarding the sample placement structure, seven sample placement holes are provided on substrate 1; six of them are 3-inch sample holes with a diameter of 76.2 mm, matching the standard 3-inch sample; the other is a 4-inch sample hole with a diameter of 101.6 mm. The seven holes are distributed in a concentric circle design, with the six 3-inch sample holes evenly distributed on the circumference and the 4-inch sample hole located at the center of the substrate (e.g., ...). Figure 3(As shown in the figure). This layout allows the central 4-inch sample to be located in the central region of the plasma, while the six peripheral 3-inch samples are located in a uniformly distributed region of the plasma, meeting the plasma energy requirements of samples of different sizes.

[0052] When used in a 75KW microwave plasma device, this substrate can meet the simultaneous growth requirements of samples of various sizes. In a typical experiment, six 3-inch and one 4-inch silicon substrates (samples) were placed into the corresponding sample holes, and diamond film growth experiments were carried out according to the same experimental procedure as in Example 1 (the parameters such as mixed gas ratio, pressure, and power were kept consistent), with a running time of 100 hours.

[0053] During the experiment, the substrate exhibited good heat dissipation, the surface temperature of each sample remained stable, the plasma morphology was uniform, and there were no localized instances of excessively high or low energy. After growth, scanning electron microscopy (SEM) revealed that the diamond films on the six 3-inch samples and one 4-inch sample were continuous and intact, with uniform grain size (average grain diameter of 5 μm) and film thickness deviation controlled within ±10 μm. This indicates that the substrate can effectively ensure the synchronous high-quality growth of samples of different sizes, which is beneficial for improving the growth efficiency and quality of diamond films and provides a reliable experimental platform for comparative studies of samples of multiple specifications.

[0054] Example 3: This embodiment is a heat-dissipating molybdenum substrate for diamond film growth, designed specifically for large-scale preparation scenarios that require the simultaneous growth of multiple 2-inch diamond film samples, and is suitable for batch production or screening experiments.

[0055] See Figure 4 The substrate 1 is cylindrical with a smooth top surface. Fifteen 2-inch sample holes, each with a diameter of 58.8 mm, are located on the top surface. These 15 holes are distributed in two layers: an inner layer of five holes evenly distributed around the same circumference, and an outer layer of ten holes evenly distributed around the inner layer. This multi-layered design ensures uniform plasma energy distribution across the limited substrate area, reducing interference caused by an excessive number of samples.

[0056] The substrate 1 has a diameter of 310 mm and a thickness of 5 mm. It is made of the same material as in Example 1, which is high-purity molybdenum with a purity of 99.95%. The large diameter of 310 mm provides ample space for 15 samples, while the thickness of 5 mm further improves the structural stability and deformation resistance of the substrate, enabling it to maintain good performance during long-term high-temperature experiments.

[0057] The smooth edge of substrate 1 is chamfered with a 1mm rounded transition. The distance between the edge and the cavity wall is relatively close. The chamfer can more effectively avoid edge discharge and ensure plasma stability on large-size substrates.

[0058] In terms of sample placement structure, the substrate 1 has 15 2-inch sample holes, each with a diameter of 58.8 mm (e.g., ...). Figure 4 (As shown in the figure). This aperture is larger than the gap of a standard 2-inch sample (50.8 mm in diameter). This design is mainly to facilitate independent heat dissipation control for each sample during batch growth, and also to facilitate sample handling.

[0059] This substrate is suitable for scenarios requiring the simultaneous growth of multiple 2-inch samples and can operate stably in a 915MHz-75KW microwave plasma device. In a batch production experiment, 15 2-inch cemented carbide substrates were placed in the sample holes, and diamond films were grown using optimized process parameters (hydrogen to methane volume ratio of 3000:60, chamber pressure of 20kPa, and microwave power of 50KW) for 100 consecutive hours.

[0060] Experimental results show that the diamond films grown on the 15 samples have uniform thickness, with an average thickness of 95 μm and a thickness deviation of ±15 μm; the adhesion between the film and the substrate is good, and the critical load of the films is greater than 80 N through scratch testing; the hardness of the film reaches more than 100 GPa, and the performance indicators are consistent; this fully demonstrates that the substrate can guarantee the growth quality and yield of diamond films, and provides an efficient and reliable solution for the large-scale preparation of 2-inch diamond films.

[0061] Example 4: The heat-dissipating molybdenum substrate of this embodiment is mainly designed for experimental needs that require the simultaneous growth of five 4-inch and one 2-inch diamond film samples, and is suitable for comparative experimental scenarios with multiple sample sizes.

[0062] In terms of material selection, the substrate uses the same high-purity molybdenum material with a purity of 99.95% as in Example 1, to ensure the material's high thermal conductivity and high-temperature stability. The dimensions are the same as in Example 1.

[0063] Experimental results show that, even without the design and fabrication of this invention, and with the experimental process parameters unchanged, stress cracks were clearly observed in all six samples after the experiment. (See [link to relevant documentation]). Figure 5 It is not suitable for experiments using high-power microwave plasma equipment and cannot meet the requirements of this experiment.

[0064] The diamond film growth heat dissipation molybdenum substrate of the present invention, by using 99.95% high-purity molybdenum material, combined with a reasonable size design of 100-400mm diameter and 2-20mm thickness, and smooth edge chamfering treatment, effectively avoids discharge phenomena during experiments, ensuring the safety and stability of equipment operation. Its diverse apertures (such as 5 four-inch + 1 two-inch, 6 three-inch + 1 four-inch, 15 two-inch) and scientific distribution layout (central symmetry, concentric circles, etc.) set according to different sample sizes meet the needs of simultaneous growth of multiple sample sizes in different experimental scenarios, improving the substrate's versatility and sample placement rationality, significantly improving the heat concentration problem, making the temperature field more uniform, reducing thermal expansion stress and deformation at high temperatures, and thus ensuring the stability of plasma density and electric field matching. This effectively protects the sample and disperses and releases thermal stress, ultimately achieving efficient growth of large-area, large-size, high-quality diamond films, improving experimental quality and yield, and providing a reliable solution for comparative experiments of multiple sample sizes and large-scale preparation.

[0065] In summary, the heat-dissipating molybdenum substrate for diamond film growth of the present invention is made of 99.95% high-purity molybdenum material to form a substrate with a diameter of 100-400mm and a thickness of 2-20mm. The smooth edge chamfering treatment prevents discharge. Combined with a variety of aperture designs to adapt to different sample sizes (4 inches, 3 inches, 2 inches), it effectively solves the problems of poor heat dissipation, uneven temperature field, easy deformation and insufficient plasma stability of traditional substrates. It can significantly improve heat concentration, reduce thermal stress and deformation, and ensure the efficient growth of large-area, large-size, high-quality diamond films, meeting the needs of multi-scenario experiments and large-scale preparation.

[0066] Furthermore, thanks to the reasonable material selection, size design, sample placement layout, and optimized heat dissipation structure, this substrate not only improves experimental safety and stability but also enhances the substrate's versatility. By improving temperature field uniformity and plasma matching stability, it significantly improves the growth quality and yield of diamond films, providing a reliable preparation basis for the application of diamond films in electronics, optics, and other fields.

[0067] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A diamond film growth heat dissipation substrate for high-power microwave plasma equipment, characterized in that, The top surface of the diamond film growth heat dissipation substrate has one or more sample holes for placing samples.

2. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, The top surface of the diamond film growth heat dissipation substrate has sample holes of one or more sizes.

3. The diamond film growth heat dissipation substrate according to claim 1 or 2, characterized in that, The diameter of the sample well is 2 inches or more.

4. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, The diamond film growth heat dissipation substrate is cylindrical.

5. The diamond film growth heat dissipation substrate according to claim 4, characterized in that, The diameter of the diamond film-grown heat dissipation substrate is 100-400 mm.

6. The diamond film growth heat dissipation substrate according to claim 1, 4, or 5, characterized in that, The thickness of the diamond film-grown heat dissipation substrate is 2-20 mm.

7. The diamond film growth heat dissipation substrate according to claim 1 or 4, characterized in that, The top surface of the diamond film growth heat dissipation substrate is smooth, and the edges of the smooth surface are chamfered.

8. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, When the sample is placed in the sample hole, the top surface of the sample is not higher than the top surface of the diamond film growth heat dissipation substrate.

9. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, The top surface of the diamond film growth heat dissipation substrate has two or more sample holes, and the closest distance between the edges of two adjacent sample holes is not less than 3 mm.

10. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, The top surface of the diamond film growth heat dissipation substrate has five or more sample holes.

11. The diamond film growth heat dissipation substrate according to claim 1, 9, or 10, characterized in that, The top surface of the diamond film growth heat dissipation substrate has five 4-inch sample holes and one 2-inch sample hole, wherein the diameter of the 4-inch sample hole is 101.6-109.6 mm and the diameter of the 2-inch sample hole is 50.8-58.8 mm; the five 4-inch sample holes are evenly distributed around the 2-inch sample hole.

12. The diamond film growth heat dissipation substrate according to claim 1, 9, or 10, characterized in that, The top surface of the diamond film growth heat dissipation substrate has six 3-inch sample holes and one 2-inch or 4-inch sample hole. The diameter of the 3-inch sample hole is 76.2-84.2 mm, the diameter of the 2-inch sample hole is 50.8-58.8 mm, and the diameter of the 4-inch sample hole is 101.6-109.6 mm. The six 3-inch sample holes are evenly distributed around the 2-inch or 4-inch sample hole.

13. The diamond film growth heat dissipation substrate according to claim 1, 9, or 10, characterized in that, The top surface of the diamond film growth heat dissipation substrate has 15 2-inch sample holes with a diameter of 50.8-58.8 mm. The 15 2-inch sample holes are distributed in two layers: the inner layer consists of 5 2-inch sample holes evenly distributed on the same circumference, and the outer layer consists of 10 2-inch sample holes evenly distributed around the inner layer.

14. The diamond film growth heat dissipation substrate according to claim 1, characterized in that, The material of the diamond film growth heat dissipation substrate includes one or more of silicon, quartz, copper, and molybdenum. The thermal conductivity of the diamond film growth heat dissipation substrate at room temperature is ≥130 W / (m·K), and the coefficient of thermal expansion at 800-1200℃ is ≤5.5×10⁻⁶. -6 / ℃.

15. The diamond film growth heat dissipation substrate according to any one of claims 1-14 is used for the high-power microwave plasma growth of diamond films on samples.

16. The application according to claim 15, characterized in that, The diamond film growth heat dissipation substrate undergoes a pretreatment annealing operation before being used for high-power microwave plasma growth of diamond films on samples. The pretreatment annealing operation includes: introducing hydrogen and oxygen, and etching under 30-50KW plasma power and 10-20KPa gas pressure conditions.

17. The application according to claim 16, characterized in that, In the pre-treatment annealing operation: The volume ratio of hydrogen to oxygen is 300-500:1; The etching time is 10-20 hours.

18. A high-power microwave plasma device, characterized in that, Includes the diamond film growth heat dissipation substrate as described in any one of claims 1-14.

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