A method and apparatus for simultaneous deposition of single crystal and polycrystalline diamond

Abstract

The application relates to a method and device for co-deposition of single crystal and polycrystal, belonging to the technical field of microwave plasma chemical vapor deposition single crystal diamond. The application guides ion bombardment on the diamond surface in plasma by bias application, improves the bombardment efficiency and ion utilization rate, enhances the surface atom migration ability, eliminates the polycrystal on the single crystal edge and the surface defects and graphite phase of the polycrystal, improves the plasma group ionization rate by adding argon, expands the plasma ball range, and improves the depositable polycrystal diamond area. The application designs a deposition table structure, deposits high-quality single crystal diamond and polycrystal diamond on the edge in MPCVD, controls the polycrystal substrate temperature on the edge of the substrate through the heat dissipation channel and the resistance wire heating effect, achieves the effect of co-deposition of single crystal and polycrystal diamond, improves the deposition efficiency, obtains high-quality electronic-grade single crystal diamond and polycrystal diamond film, and provides basic materials for diamond semiconductor and polycrystal diamond heat dissipation application.

Description

Technical Field

[0001] The present invention belongs to the technical field of diamond single crystals and polycrystalline materials and their preparation, and relates to a method and apparatus for high-rate growth of diamond single crystals by microwave plasma chemical vapor deposition. This method achieves the purpose of co-deposition of single crystals and polycrystalline by regulating the substrate temperature of the growing polycrystalline and single crystal by combining a deposition table with an external power supply heating mode and a bias power supply. The present invention also provides a special substrate holder structure for co-deposition of polycrystalline and single crystal. By providing different bottom heat dissipation structures for single crystal substrates and polycrystalline substrates, combined with external power supply heating, the temperature of both single crystal substrates and polycrystalline substrates can be simultaneously regulated. In addition, the bias power supply connected to the substrate table continuously provides bias to the substrate surface, guiding ion bombardment to improve the growth quality of single crystals and polycrystalline, thereby achieving the purpose of growing high-quality single crystals and polycrystalline. Background Art

[0002] The use of chemical vapor deposition (CVD) to grow polycrystalline diamond films on heterogeneous substrates was first proposed in the early 1980s. Due to its low deposition cost and ability to deposit polycrystalline diamond films over large areas, the technology for heterogeneously growing polycrystalline diamond films has developed rapidly in recent years and has reached technical maturity. However, due to factors such as inconsistent grain orientation caused by competitive growth between grains, uneven temperature caused by heat dissipation from the substrate surface, and varying states of the plasma ball over a large area, coupled with temperature variations, polycrystalline diamond films contain numerous grain boundaries and defects, making them unsuitable for widespread application in electronic devices. With the invention of MPCVD equipment, which offers higher energy density and a cleaner chamber structure, the homoepitaxial single-crystal diamond deposited by it is of far superior quality to polycrystalline diamond films. Most diamond films grown homoepitaxially using single-crystal diamond as a seed crystal are now widely used in electronics applications. However, due to the slow homoepitaxial growth rate of single-crystal diamond (SCD), typically less than 5-10 microns per hour, growing single-crystal diamond with a thickness in the millimeter range requires continuous growth for over 100-200 hours, placing high demands on the stability of the growth system. Furthermore, due to the limitations of the homoepitaxial growth method, the seed crystal size of single-crystal diamond is small, which prevents full utilization of the plasma sphere excited within the chamber of a typical MPCVD system, significantly increasing costs. To address this issue in the development of homoepitaxial single-crystal diamond, the traditional approach is to increase the growth rate by increasing process parameters such as methane concentration and temperature. However, excessively high methane concentrations and temperatures can lead to excessive surface stress on the SCD, resulting in defects. Another approach is to increase the chamber pressure of the microwave CVD system, compressing the plasma sphere area and achieving high energy density in a small area for high-speed, targeted growth of SCD. However, increasing the chamber pressure can cause the microwave plasma sphere to destabilize, and maintaining the same temperature in a microwave CVD system results in reduced power, which in turn hinders high-speed SCD growth. To address these issues, Professor Wang Hongxing's team at Xi'an Jiaotong University (CN 112813497 B) used an auxiliary ring prepared from polycrystalline samples to improve the temperature distribution on the surface of single-crystal samples during deposition, achieving high-speed growth. Li Hongdong et al. from Jilin University (CN100500951C) used a sample holder made of polycrystalline diamond and diamond powder to improve the stability of single-crystal diamond growth. Both approaches aim to reduce the cost of single-crystal growth by increasing the growth rate. While effective, simply improving single-crystal deposition efficiency does not fully utilize the plasma. Another approach achieves stable growth by modifying the plasma ball composition or discharge conditions. Element 6 has increased the growth rate of single-crystal diamond by adding nitrogen. While the addition of nitrogen accelerates the migration of atoms from the single crystal surface to the step roots, forming step growth, nitrogen doping alters the composition of the diamond, making it difficult to grow high-purity semiconductor single-crystal diamond.

[0003] Advanced single-crystal diamond cost reduction technology requires not only efficient single-crystal growth rate, but also high plasma utilization. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for co-deposition of single crystal and polycrystalline diamond, which utilizes a novel substrate table structure and oxygen as an auxiliary gas to achieve efficient and high-quality diamond co-deposition.

[0005] The present invention adopts the following technical solution: a method for co-deposition of single-crystal diamond and polycrystalline diamond, characterized in that a single-crystal growth substrate is placed in the central area of ​​an MPCVD substrate table, and a ring-shaped polycrystalline substrate is placed in the outer edge area; the growth process utilizes the different growth mechanisms of single crystals and polycrystalline diamonds, single-crystal diamond grows by step flow formed by the movement of surface carbon atoms, and polycrystalline diamond grows by competitive columnar crystals formed by multiple single crystals on the surface; the concentrations of carbon groups in the microwave plasma required by the two are different, so the single-crystal diamond in the central area of ​​the plasma can be co-deposited with the polycrystalline diamond in the edge area.

[0006] Furthermore, the substrate stage utilizes two structural configurations for controlling the edge temperature of the polycrystalline substrate. The central region of the substrate stage structure is used to house single-crystal diamond seeds, while the outer region is used to house silicon rings for polycrystalline diamond deposition. The silicon ring temperature is maintained at an optimal level for polycrystalline diamond deposition by regulating the heat dissipation channel beneath the polycrystalline deposition area. Oxygen is added during the deposition process to improve the quality of the deposited crystal, and periodic oxygen etching with bias voltage applied to the substrate reduces the formation of graphite phases in polycrystalline deposition and edge polycrystalline in single crystal deposition. By adjusting the width of the heat dissipation channel beneath the polycrystalline substrate and the power of the resistance wire heating beneath the polycrystalline, the polycrystalline substrate surface temperature is set to an optimal diamond growth temperature, achieving co-deposition of single and polycrystalline diamonds.

[0007] Furthermore, the bottom of the substrate table is connected to a bias power supply, which continuously outputs a negative bias voltage to the substrate surface during the co-deposition process of polycrystals and single crystals, guiding the positive ions in the plasma to continuously bombard the growth surfaces of the single crystals and polycrystals, providing energy for the step flow growth on the surface of the single crystal and the columnar crystal growth of the polycrystals, and removing the secondary nucleation grains on the surface of the single crystal and the graphite phase on the surface of the polycrystal.

[0008] Furthermore, the method for co-deposition of single crystal and polycrystalline diamond is characterized in that the co-deposition is a molybdenum support structure for co-deposition of polycrystalline and single crystal, the central single crystal substrate and the edge polycrystalline annular substrate are jointly arranged, and a growth method is combined with oxygen and bias power supply cyclic etching through a resistance wire and a molybdenum support heat dissipation structure; argon is used as an auxiliary gas, oxygen etching is periodically introduced, and a negative bias is applied to the substrate to assist, and the specific steps are as follows:

[0009] Step 1: Clean the single crystal diamond substrate with a 1:3 mixture of sulfuric acid and nitric acid and acetone; Grind the surface of the silicon ring substrate with diamond particles with a particle size of 4-6 microns for 8-12 minutes until the surface is covered with tiny scratches;

[0010] Step 2: Place the single crystal diamond and silicon ring substrate prepared in step 1 into the MPCVD device and introduce H2 / O2 plasma to etch surface defects;

[0011] Step 3: After step 2, adjust the chamber pressure and power of the MPCVD equipment until the surface of the single crystal diamond substrate reaches a growth temperature of 820-1000°C;

[0012] Step 4: After step 3, the temperature of the silicon substrate at the edge is heated to the growth temperature of polycrystalline diamond 850-1100°C by adjusting the power of the molybdenum support outer ring resistance wire, and methane and argon are introduced to start growth;

[0013] Step 5: After step 4, turn on the bias power supply connected to the substrate stage, set the bias power supply output voltage, and continuously apply a negative bias voltage to the substrate surface;

[0014] Step 6: After the completion of step 5, during the growth of single crystals and polycrystalline materials, a certain amount of 1% oxygen is introduced into the chamber for etching in a cycle of 43-47 hours.

[0015] Furthermore, a novel substrate stage structure used in the present invention is a substrate stage structure connected to a bias power supply for co-deposition of polycrystalline diamond and single crystal diamond, such as Figure 1 As shown, the bias power supply is used to continuously apply bias to the substrate surface. This approach is used to guide positive ions in the plasma to bombard the substrate surface. The central area of ​​the substrate table is a single crystal grown substrate, and the edge area is a polycrystalline grown substrate.

[0016] Furthermore, the polycrystalline diamond substrate is in the shape of a processed ring, and the top view of the substrate table is as follows: Figure 2 As shown, the inner and outer diameters of the polycrystalline ring can be freely adjusted to deposit and grow polycrystalline diamond sheets that meet various size requirements. The substrate of the single crystal growth area in the center is a single crystal substrate, and the polycrystalline deposition substrate on the outside is a single crystal silicon ring.

[0017] Furthermore, a groove is provided under the polycrystalline diamond substrate, which is suspended from the molybdenum support. The part of the silicon wafer in contact with the molybdenum support dissipates heat quickly, while the suspended part dissipates heat poorly, causing the overall temperature of the silicon wafer to rise. By setting the groove width, the heat dissipation of the polycrystalline substrate can be changed, so that the silicon substrate at the edge of the plasma ball can reach an appropriate temperature.

[0018] Furthermore, the outer ring of the bottom of the molybdenum tray has a circle of resistance wire for heating. The function of this resistance wire is to assist the surface temperature of the polycrystalline substrate at the edge of the molybdenum tray to reach a suitable growth temperature through heating, improve the temperature uniformity of the center edge of the molybdenum tray, and ensure that the edge polycrystalline substrate reaches a suitable diamond growth temperature during the single crystal growth process.

[0019] Furthermore, the lower end of the substrate table is connected to a bias power supply, which will output a negative bias voltage to the single crystal and polycrystalline substrates, attracting positive ions in the plasma ball to continuously bombard the substrate surface, eliminating small polycrystalline particles generated during the growth process of the single crystal substrate surface and non-diamond phases generated during the growth process of the polycrystalline substrate surface.

[0020] The present invention provides an efficient method for co-deposition of polycrystalline and single-crystalline diamonds and a special deposition table structure, which enable different areas inside a chamber to simultaneously meet the deposition conditions for single-crystalline diamond and polycrystalline diamond, thereby improving the utilization rate of the plasma in the chamber, reducing the cost of single-crystal growth, and improving the efficiency of MPCVD diamond synthesis. The high-quality single crystals are used in diamond semiconductor applications, while the synchronously grown polycrystalline diamonds can be used in diamond heat dissipation applications, providing an effective solution for the preparation of high-quality semiconductor diamonds and the mass production of heat-dissipating-grade diamonds.

[0021] Advantages and functions of the present invention

[0022] 1. Innovation analysis

[0023] The innovations of the present invention are: 1. The plasma ball is not fully utilized during the growth of CVD single-crystal diamond. By arranging a silicon ring for polycrystalline diamond growth on the edge of the molybdenum support, the concentration of carbon groups in the plasma required for polycrystalline diamond growth is lower than that of single-crystal diamond, thereby increasing the utilization efficiency of the plasma ball and saving costs.

[0024] 2. The edge of the molybdenum support is heated by the combined action of heat dissipation channels and resistance wires to increase the temperature of the polycrystalline growth substrate in the edge area, solving the problem of large temperature difference between the center and the edge, and enabling the simultaneous deposition of single crystal diamond and polycrystalline diamond.

[0025] 3. By using a bias power supply to apply a negative bias to the substrate surface, the positive ions in the plasma are guided to continuously bombard the substrate surface, and the non-diamond phase on the sample surface is continuously etched during the single crystal and polycrystalline co-deposition process, achieving the purpose of growing high-quality single crystal and polycrystalline diamond.

[0026] 4. During the co-deposition of single-crystal and polycrystalline diamond, argon is introduced into the chamber as an auxiliary gas. As an auxiliary gas, argon can stabilize plasma radicals, increase additional ionization in the plasma reaction, provide high-quality argon ions to bombard the substrate surface, transfer energy to carbon-containing radicals, provide higher energy for atomic migration in surface step growth, and improve the growth quality of single-crystal diamond. In addition, the introduction of argon will expand the area of ​​the plasma ball, expand the MPCVD deposition area, and improve the edge polycrystalline diamond deposition efficiency.

[0027] 5. During the co-deposition process of single crystals and polycrystalline, oxygen is periodically introduced into the chamber as an auxiliary gas. Oxygen as an auxiliary gas can etch defects in diamond and graphite, thereby ensuring high deposition efficiency while improving the quality of diamond crystals.

[0028] The beneficial effects of the present invention and the prior art are:

[0029] (1) The present invention designs a substrate support structure and growth method for co-depositing single-crystal diamond and polycrystalline diamond. Compared with the original single-crystal diamond deposition method, the plasma utilization rate is higher, the cost is lower, and the diamond output is higher, which effectively provides a solution for the mass production of single-crystal and polycrystalline diamond.

[0030] (2) The present invention improves the plasma deposition capability by introducing argon and oxygen cyclic etching auxiliary bias applied to the MPCVD system for single crystal and polycrystal co-deposition. The periodic etching auxiliary bias promotes the step flow growth on the surface of the single crystal and the columnar crystal growth on the surface of the polycrystal, thereby improving the quality of the deposited diamond crystal.

[0031] The present invention improves diamond deposition efficiency and crystal quality by designing a substrate holder structure for single-crystal and polycrystal co-deposition, combining negative bias, assisting argon and oxygen, and cyclically etching the substrate, thereby providing an efficient solution for mass production of semiconductor single-crystal diamond and polycrystalline diamond. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the single crystal and polycrystal co-deposition platform structure;

[0033] Figure 2 This is a schematic diagram of the top view of the single crystal and polycrystal co-deposition platform;

[0034] Figure 3 Schematic diagram of the single crystal and polycrystal co-deposition process;

[0035] Figure 4 Schematic diagram of atomic migration on the growth step surface of single crystal diamond;

[0036] Figure 5 Schematic diagram of competitive growth of columnar crystals on the surface of polycrystalline diamond;

[0037] Figure 6 Schematic diagram of the surface morphology of single crystal diamond growth;

[0038] Among them: 1. Polycrystalline diamond substrate holder; 2. Polycrystalline diamond heat sink; 3. Resistance wire heater; 4. Single crystal diamond substrate holder; 5. Bias power supply; 6. Resistance heating wire power supply; 7. Plasma ball under applied bias; 8. Polycrystalline substrate; 9. Single crystal substrate; 10. Atoms on the single crystal step surface; 11. Columnar crystals on the polycrystalline surface; 12. Columnar crystals inside the polycrystalline; 13. Graphite phase defects on the polycrystalline surface; 14. Secondary nucleation grains of single crystal diamond. (The figure does not include reference number 14.)

[0039] Among them: the size of the deposition table is 3 inches in diameter, and the inner diameter of the polycrystalline diamond ring can be adjusted from 2 inches to 70 mm. This distance depends on the ratio of the deposited single crystal diamond and polycrystalline diamond areas. DETAILED DESCRIPTION

[0040] Implementation steps

[0041] A method of co-deposition of single crystal and polycrystalline diamond of the present invention is as follows:

[0042] Step 1: Use a mixed solution of sulfuric acid and nitric acid (1:3) and acetone to clean the single crystal diamond substrate and the polycrystalline diamond substrate in sequence.

[0043] Step 2: Place the single crystal diamond and polycrystalline diamond substrates prepared in step 1 into an MPCVD device and introduce H2 / O2 plasma to etch surface defects;

[0044] Step 3: After step 2, turn on the power supply of the resistance heating wire, adjust the heating power of the resistance wire, and measure the surface temperature of the polycrystalline ring substrate at the same time;

[0045] Step 4: After step 3, apply negative bias to the substrate and introduce argon / methane / hydrogen (1 / 5 / 100)

[0046] Step 5: After step 4, adjust the power of the resistance heating wire so that the polycrystalline substrate and the single crystal diamond substrate reach the diamond deposition temperature at the same time;

[0047] Step 6: Adjust the oxygen flow rate during the growth process, periodically introduce 1% oxygen every 45 hours, and turn off the oxygen after etching for 10 minutes.

[0048] 1. Device structure and function

[0049] The device and its functions of the present invention are described below with reference to the accompanying drawings and specific examples.

[0050] The embodiment of the present invention discloses a molybdenum support structure and growth method for co-deposition of single crystal diamond and polycrystalline diamond, including a single crystal diamond substrate support 4 arranged in the center of the molybdenum support and a polycrystalline diamond substrate support 1 around it. Figure 1 As shown, the heat dissipation slot 2 and the heating resistance wire 3 arranged below the polycrystalline substrate holder, as well as the resistance wire power supply 6 for regulating the temperature of the resistance wire, increase the temperature of the polycrystalline substrate by affecting heat dissipation and active heating.

[0051] The top view of the above-mentioned single crystal and polycrystalline diamond co-deposition support is as follows Figure 2 As shown, the single crystal substrate is square and the polycrystalline substrate is ring-shaped.

[0052] The bias power supply 5 for applying a negative bias to the substrate surface applies a negative bias to the surface of the single crystal substrate and the polycrystalline substrate during the deposition process. Figure 3 As shown, it includes: a single crystal diamond substrate 9, a polycrystalline diamond substrate 8, and a plasma 7 under applied bias.

[0053] Taking Ib-type single crystal diamond and (100) oriented single crystal silicon ring as examples of single crystal and polycrystalline diamond substrate materials, respectively, their surface roughness is ≤1nm. Before use, they are cleaned with a mixed solution of sulfuric acid and nitric acid in a volume ratio of 1:3. Then they are cleaned with acetone, alcohol, and deionized water and dried. The single crystal diamond substrate 9 and the polycrystalline diamond ring substrate 8 are placed in an MPCVD device with a bias power supply. First, a 1% concentration of O2 / H2 plasma is introduced to etch the surface and subsurface defects for 2h. Then, they are placed on a CVD sample growth table for enhanced bias nucleation, with a negative voltage of -500V. The single crystal diamond substrate 9 and the polycrystalline diamond ring substrate 8 are placed in the MPCVD for growth. The growth process is: gas pressure 100Torr, gas flow rate 500sccm, CH4 / H2=5%, 1% Ar, substrate temperature 900℃, and negative bias is continuously applied to the substrate during the growth process, with a negative voltage of -50V.

[0054] During the growth process, electrons and positive ions transfer energy to carbon-containing groups on the surface of a single-crystal diamond. The energy provided causes atoms 10 on the step surface to continuously migrate toward the bottom of the step, forming step flow growth. The growth mechanism of a polycrystalline diamond surface is a columnar growth pattern formed by the competition of multiple single-crystal diamonds 11. The difference between the two growth patterns is that the step flow growth of a single crystal requires a dense atomic-level arrangement to proceed, so a large number of dissociated carbon-containing groups are required to provide a sufficiently dense atomic-level arrangement of carbon atoms. Polycrystalline growth, on the other hand, is a columnar crystal growth pattern formed by the competition of multiple single-crystal diamonds 11. In this pattern, individual diamond crystals do not need to grow completely. The growth of polycrystalline diamond is composed of the fastest-growing single-crystal diamonds 11, while the slower-growing single-crystal diamonds 12 are overshadowed by the competition of other crystals. Therefore, the dense packing during the growth of polycrystalline diamond is more macroscopic than that of single-crystal diamond, at the crystal level, which allows the formation of pores. Therefore, the concentration of carbon-containing groups required for the growth of polycrystalline diamond is lower than that of single-crystal diamond. Therefore, this substrate configuration with a single crystal center and polycrystalline edges can ensure that the carbon-containing group concentrations required for single crystal diamond growth and polycrystalline diamond growth are consistent with the plasma distribution, effectively improving the efficiency of diamond deposition. And the surface is continuously bombarded by positive and negative ions in the plasma, such as Figure 3 As shown, continuous positive ion bombardment removes the fine grains 14 on the surface of the single crystal. Figure 6 The graphite phase and the black defect 13 on the surface of the polycrystalline have a certain etching effect, which improves the quality of crystal growth.

[0055] During the co-deposition process of single crystal and polycrystalline diamond, oxygen with a flow rate of 3 sccm is introduced into the chamber for 10 minutes every 40 hours. The introduction of oxygen has a strong etching effect on the surface of single crystals and polycrystalline crystals, and has a stronger etching effect on larger defects and graphite phases. In order not to affect the growth rate of diamond single crystals and polycrystalline crystals, oxygen is introduced once every 40 hours. By intermittently introducing oxygen etching, the methane concentration can be appropriately increased, thereby improving the quality of the grown single crystals and polycrystalline crystals while maintaining a higher growth rate.

Claims

1. A method for co-deposition of single crystal and polycrystalline diamond, characterized in that: A single crystal growth substrate is placed in the center of the MPCVD substrate stage, while a ring-shaped polycrystalline substrate is placed in the outer edge. The growth process utilizes the different growth mechanisms of single crystals and polycrystalline diamonds. Single crystal diamond grows as a step flow formed by the movement of surface carbon atoms, while polycrystalline diamond grows as a competitive columnar crystal formed by multiple single crystals on the surface. The concentrations of carbon groups in the microwave plasma required for both are different, so single crystal diamond in the center of the plasma can be deposited together with polycrystalline diamond in the edge area. The substrate stage uses two structural settings for regulating the temperature of the edge of the polycrystalline substrate; the central area of ​​the substrate stage structure is used to place a single-crystal diamond seed crystal, and the outer area is used to place a silicon ring for depositing polycrystalline diamond. The temperature of the silicon ring is ensured to be a suitable temperature for polycrystalline diamond deposition by regulating the groove area used for heat dissipation below the polycrystalline deposition area; oxygen is added during the deposition process to improve the quality of the deposited crystal, and the generation of graphite phase in polycrystalline deposition and edge polycrystalline in single crystal deposition is reduced by periodically applying bias oxygen etching to the substrate; the surface temperature of the polycrystalline substrate is set to a suitable growth temperature for diamond by adjusting the width of the heat dissipation groove below the polycrystalline substrate and the heating power of the resistance wire below the polycrystalline, thereby achieving the purpose of single crystal and polycrystalline co-deposition; Co-deposition is a molybdenum support structure in which polycrystalline and single crystal are deposited together. The central single crystal substrate and the edge ring-shaped polycrystalline substrate are set together. The growth method is combined with oxygen and bias power supply cyclic etching through the resistance wire and molybdenum support heat dissipation structure. Argon is used as the auxiliary gas, oxygen etching is periodically introduced, and a negative bias is applied to the substrate to assist. The specific steps are as follows: Step 1: Clean the single crystal diamond substrate with a mixture of sulfuric acid and nitric acid and then with acetone; polish the surface of the silicon ring substrate with diamond particles having a particle size of 4-6 microns for 8-12 minutes until the surface is covered with tiny scratches; Step 2: Place the single crystal diamond and silicon ring substrate prepared in step 1 into the MPCVD device and introduce H2 / O2 plasma to etch surface defects; Step 3: After step 2, adjust the chamber pressure and power of the MPCVD equipment until the surface of the single crystal diamond substrate reaches a growth temperature of 820-1000°C; Step 4: After step 3, the temperature of the silicon substrate at the edge is heated to the growth temperature of polycrystalline diamond 850-1100°C by adjusting the power of the molybdenum support outer ring resistance wire, and methane and argon are introduced to start growth; Step 5: After step 4, turn on the bias power supply connected to the substrate stage, set the bias power supply output voltage, and continuously apply a negative bias voltage to the substrate surface; Step 6: After the completion of step 5, during the growth of single crystals and polycrystalline materials, a certain amount of 1% oxygen is introduced into the chamber for etching in a cycle of 43-47 hours.

2. The method for co-deposition of single crystal and polycrystalline diamond according to claim 1, characterized in that: The bottom of the substrate table is connected to a bias power supply, which continuously outputs a negative bias voltage to the substrate surface during the co-deposition process of polycrystals and single crystals, guiding the positive ions in the plasma to continuously bombard the growth surfaces of the single crystals and polycrystals, providing energy for the step flow growth on the surface of the single crystal and the columnar crystal growth of the polycrystals, and removing the secondary nucleation grains on the surface of the single crystal and the graphite phase on the surface of the polycrystal.

3. The method for co-deposition of single crystal and polycrystalline diamond according to claim 1, characterized in that: The substrate table structure is a substrate table structure connected to a bias power supply for co-deposition of polycrystalline diamond and single crystal diamond, wherein the bias power supply is used to continuously apply a bias voltage to the substrate surface. This approach is used to guide the positive ions in the plasma to bombard the substrate surface. The central area of ​​the substrate table is a single crystal grown substrate, and the edge area is a polycrystalline grown substrate.

4. The method for co-deposition of single crystal and polycrystalline diamond according to claim 3, characterized in that: The annular polycrystalline substrate is in the shape of a processed ring. The inner and outer diameters of the polycrystalline ring can be freely adjusted to deposit and grow polycrystalline diamond sheets that meet various size requirements. The substrate of the single crystal growth area in the center is a single crystal substrate, and the outer polycrystalline deposition substrate is a single crystal silicon ring.

5. The method for co-deposition of single crystal and polycrystalline diamond according to claim 3, characterized in that: A groove is provided under the annular polycrystalline substrate, which is suspended from the molybdenum support. The part of the silicon wafer in contact with the molybdenum support dissipates heat quickly, while the suspended part dissipates heat poorly, causing the overall temperature of the silicon wafer to rise. By setting the width of the groove, the heat dissipation of the polycrystalline substrate can be changed, so that the silicon substrate at the edge of the plasma ball reaches an appropriate temperature.

6. The method for co-deposition of single crystal and polycrystalline diamond according to claim 5, characterized in that: The outer ring at the bottom of the molybdenum support has a circle of resistance wire for heating. The function of this resistance wire is to assist the surface temperature of the polycrystalline substrate at the edge of the molybdenum support to reach a suitable growth temperature through heating, improve the temperature uniformity of the center edge of the molybdenum support, and ensure that the edge polycrystalline substrate reaches a suitable diamond growth temperature during the single crystal growth process.

7. The method for co-deposition of single crystal and polycrystalline diamond according to claim 3, characterized in that: The lower end of the substrate table is connected to a bias power supply, which outputs a negative bias voltage to the single crystal and polycrystalline substrates, attracting positive ions in the plasma ball to continuously bombard the substrate surface, eliminating small polycrystalline particles generated during the growth process of the single crystal substrate surface and non-diamond phases generated during the growth process of the polycrystalline substrate surface.

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