A method for preparing high-quality single crystal diamond with removed poly-crystal defects

Abstract

The present application belongs to the field of diamond preparation, and discloses a high-quality single-crystal diamond preparation method for removing polycrystal defects. Through screen printing and plasma-assisted etching, the (100) surface around the black point-shaped polycrystal is directionally etched by cerium oxide, and a square groove is etched. Then, the slurry of iron oxide or nickel oxide is printed by screen printing, the black point-shaped polycrystal is covered with the slurry, and the black point-shaped polycrystal is removed by plasma-assisted etching. Then, the etched groove is filled by a horizontal growth process, so that the growth defects can be removed, and high-quality single-crystal diamond can be obtained. The present application can greatly reduce the waste rate of single-crystal diamond products and improve the utilization rate of single-crystal diamond. The present application is beneficial to saving production cost and improving efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of diamond preparation, and relates to a single crystal diamond preparation method, in particular to a high-quality single crystal diamond preparation method for removing polycrystal defects. BACKGROUND

[0002] Natural diamond reserves are rare and expensive, and are often used in luxury consumption fields such as jewelry; diamond prepared by high-temperature and high-pressure method has many impurities and is difficult to be doped, and is mostly used in abrasive mold fields, and both of them are in granular form and cannot meet the actual needs of single crystal diamond in high-tech fields. Microwave chemical vapor deposition (MPCVD) has become the preferred solution for preparing high-quality diamond due to its large plasma density and no electrode pollution.

[0003] In the growth process of single crystal diamond, problems such as instability of the ball, poor processing of the seed crystal, or too high temperature of individual seed crystals during the growth process may cause black point-like polycrystals to grow in the single crystal region during the growth process, resulting in growth defects and causing the growth product to be scrapped. SUMMARY

[0004] In view of the problems in the prior art, the purpose of the present application is to provide a high-quality single crystal diamond preparation method for removing polycrystal defects.

[0005] To achieve the purpose of the present application, the specific technical solutions are as follows:

[0006] A high-quality single crystal diamond preparation method for removing polycrystal defects, comprising the following steps:

[0007] (1) An organic slurry is prepared by mixing terpineol, butyl carbitol acetate, dibutyl phthalate and cerium oxide powder in a mass ratio of 4-8:1-3:1-3:3-5; a cleaned single crystal diamond seed crystal is placed under a screen plate, and the black point-like polycrystals of the single crystal diamond seed crystal are aligned with the screen holes for the first time screen printing, the screen holes are square in shape, and the size of the screen holes is larger than that of the black point-like polycrystals; an organic slurry layer is then covered on the black point-like polycrystals of the single crystal diamond seed crystal, and the thickness is 2-5 microns;

[0008] (2) The single crystal diamond seed crystal after the first screen printing is dried;

[0009] (3) The dried single crystal diamond seed crystal is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching to obtain a single crystal diamond seed crystal after the first etching;

[0010] (4) The single crystal diamond seed crystal after the first etching is cleaned and dried;

[0011] (5) configuring the organic slurry by mass ratio of 4-8:1-3:1-3:3-5 of terpineol, butyl carbitol acetate, dibutyl phthalate, iron oxide or nickel oxide; placing the single crystal diamond seed crystal treated in step (4) under a screen board, and screen printing the black dot polycrystal on the screen board, the size of the screen hole being larger than that of the black dot polycrystal, the size of the screen hole being smaller than that of the screen hole in the first screen printing, and then covering the black dot polycrystal of the single crystal diamond seed crystal on which the first screen printing has been performed with a layer of the organic slurry, the thickness being 2-5 microns;

[0012] (6) drying the single crystal diamond seed crystal after the second screen printing;

[0013] (7) sequentially performing second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching on the dried single crystal diamond seed crystal, to obtain the single crystal diamond seed crystal after the second etching;

[0014] (8) cleaning the single crystal diamond seed crystal after the second etching, and blowing dry;

[0015] (9) sequentially performing etching and growth on the seed crystal treated in step (8);

[0016] (10) after the growth, increasing the temperature by 100-150℃ based on the growth temperature in step (9), keeping the temperature for 1-2 hours, then cooling to room temperature, and turning off the microwave, to obtain the single crystal diamond.

[0017] Preferably, step (3) is specifically:

[0018] S31. first oxygen etching: the atmosphere is at least one of oxygen, argon, and air, the pressure is 5-10 KPa, the temperature is 200-500℃, and the etching time is 5-10 min;

[0019] S32. first plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen, and argon, the volume ratio is 5-8:3:2, the pressure is 8-15 KPa, the temperature is 500-900℃, and the etching time is 10-120 min;

[0020] S33. first plasma etching: the atmosphere is at least one of oxygen, argon, nitrogen, air, and carbon monoxide, the pressure is 5-10 KPa, the temperature is 200-500℃, and the etching time is 5-40 min.

[0021] Preferably, step (7) is specifically:

[0022] S71. second oxygen etching: the atmosphere is at least one of oxygen, argon, and air, the pressure is 5-10 KPa, the temperature is 200-500℃, and the etching time is 5-10 min;

[0023] S72. Second plasma and metal active catalytic etching: atmosphere is at least one of hydrogen, carbon monoxide, argon, helium, pressure is 8-15KPa, temperature is 500-900℃, etching time is 10-120min;

[0024] S73. Second plasma etching: atmosphere is at least one of oxygen, argon, nitrogen, air, carbon monoxide, pressure is 5-10KPa, temperature is 200-500℃, etching time is 5-40min.

[0025] Preferably, step (4) or (8) is specifically: put the single crystal diamond seed crystal into aqua regia solution, and clean for 3-10min; then sequentially clean with deionized water, acetone, anhydrous ethanol, deionized water for 5-10min, and dry with nitrogen.

[0026] Preferably, in step (2) or (6), the drying temperature is set to 80-100℃.

[0027] Preferably, step (9) is specifically:

[0028] S91. Put the seed crystal cleaned in step (8) into a substrate table, and then put the substrate table into a deposition cavity, and after vacuumizing, start to input hydrogen, and start the microwave, and etch for 0.5-2h at a temperature of 700-1000℃ and a pressure of 17-21kPa;

[0029] S92. After etching is completed, input methane, carbon dioxide, argon, nitrogen, and grow for 180-200h in an environment with a pressure of 20-24kPa and a temperature of 900-1050℃.

[0030] Further preferably, step (10) is specifically: after growth is completed, stop inputting methane, carbon dioxide, argon, nitrogen, increase the temperature by 100-150℃ based on the growth temperature in step (9), and keep warm for 1-2h, then decrease the temperature by 100-200℃ as a gradient, and keep warm for 1-2h at each gradient temperature, until room temperature, turn off the microwave, and stop inputting hydrogen, to obtain the single crystal diamond.

[0031] Further preferably, in step (9), the substrate table comprises a substrate table main body in a cylindrical structure or a circular table structure, a circular groove is arranged on the upper surface of the substrate table main body, and a plurality of grid grooves for accommodating seed crystals are arranged at the bottom of the circular groove;

[0032] The width of the grid groove is 0.15-0.5mm larger than the width of the seed crystal, the depth of the grid groove is 0.05-0.15mm smaller than the thickness of the seed crystal, and the limiting step width between two grids is 0.9-1.5mm; the diameter of the circular groove is 1-3mm smaller than the diameter of the upper surface of the substrate table, and the depth of the circular groove is 0.5-1mm larger than the difference between the thickness of the seed crystal and the depth of the grid groove.

[0033] Further preferably, the center of the circular groove coincides with the center of the main surface of the substrate table body.

[0034] Further preferably, the seed crystal is a square columnar structure, and the grid groove is a square columnar hollow structure.

[0035] Further preferably, the grid grooves are uniformly arranged on the upper surface of the substrate table body; and the grid grooves are arranged in any one of the following ways: a plurality of linear arrays, a plurality of circumferential arrays, and a plurality of rectangular arrays on the upper surface of the substrate table body.

[0036] Further preferably, the distance between adjacent grid grooves is 0.9-1.5mm; and the adjacent grid grooves are in communication with each other.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] (1) The disclosed preparation method of high-quality single crystal diamond removing polycrystalline defects, by screen printing and plasma-assisted etching, realizes the directional etching of cerium oxide on the (100) surface around the black point-shaped polycrystalline, etches a square groove, then the slurry of iron oxide or nickel oxide is printed by screen printing, the black point-shaped polycrystalline is covered with the above-mentioned slurry, and then the etched groove is filled by the lateral growth process, so that the growth defects can be removed, and the single crystal diamond with good quality can be obtained.

[0039] (2) The present application can greatly reduce the waste rate of single crystal diamond products and improve the utilization rate of single crystal diamond. It is beneficial to save production cost and improve efficiency. DETAILED DESCRIPTION

[0040] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0041] Figure 1 It is a process flow chart of the present application;

[0042] Figure 2 It is a top view structure diagram of the substrate table for growing single crystal diamond of the present application;

[0043] Figure 3 A sectional view of a substrate table for growing single crystal diamond;

[0044] Figure 4 A Figure 3 partial enlarged view. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present application, the following will be combined with the drawings and the preferred embodiments to make a more comprehensive and detailed description of the present application, but the protection scope of the present application is not limited to the following specific embodiments.

[0046] Unless otherwise defined, all the professional terms used in the following have the same meaning as that generally understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing the specific embodiments and are not intended to limit the protection scope of the present application.

[0047] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0048] Example 1

[0049] As Figures 2-4 shown, the present embodiment provides a substrate table for growing single crystal diamond, which includes a substrate table body 1 in the form of a circular truncated cone, and the substrate table body 1 is in the form of a circular truncated cone with a top surface diameter of 53 mm. It should be noted that the top surface and the side surface of the substrate table body 1 are circularly arcuate, and the upper surface of the substrate table body 1 is provided with a circular groove 2, which has a diameter of 52 mm and a depth of 0.65 mm.

[0050] The circular groove 2 is uniformly provided with 23 grid grooves 3 in the form of square columnar hollow structures, which are used for accommodating and limiting the seed crystals and are arranged in a linear array in a layered manner. The length, width and height parameters of the seed crystals to be accommodated are 5 mm x 5 mm x 0.3 mm, the width of each grid groove 3 is 5.2 mm, and the depth of each grid groove 3 is 0.15 mm.

[0051] In the present embodiment, the distance between adjacent grid grooves 3 is 0.9 mm. Moreover, adjacent grid grooves 3 are interconnected, which in the present embodiment is manifested as that adjacent grid grooves 3 are interconnected at the connecting top corners, further reducing the temperature difference of each point of the entire substrate table and the temperature difference of each seed crystal.

[0052] Example 2

[0053] The present embodiment provides a method for preparing high-quality single crystal diamond with polycrystalline defects removed, as Figure 1 shown, comprising the following steps:

[0054] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, and 3g of cerium oxide powder are configured into an organic slurry, a single crystal diamond seed crystal after cleaning is placed under a screen plate, and a black dot-shaped polycrystal of the single crystal diamond seed crystal is aligned with a screen hole for first screen printing, the screen hole shape is a square, and the size of the screen hole is greater than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially overlaid on the black dot-shaped polycrystal of the single crystal diamond seed crystal;

[0055] (2) The single crystal diamond after the first screen printing is placed in an oven, and is kept at a temperature of 80℃ for 60min, and is dried;

[0056] (3) The single crystal diamond seed crystal after drying is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching, specifically:

[0057] S31. First oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0058] S32. First plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen, and argon, the volume ratio is 5:3:2, the pressure is 8KPa, the temperature is 500℃, and the etching time is 120min;

[0059] S33. First plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0060] (4) Cleaning: the single crystal diamond seed crystal after etching in step (3) is placed in aqua regia solution, and is cleaned for 10min, and then is sequentially ultrasonically cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and is dried with nitrogen blowing;

[0061] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, and 3g of iron oxide powder are configured into an organic slurry, the single crystal diamond seed crystal after cleaning in step (4) is placed under a screen plate, and a black dot-shaped polycrystal is aligned with a screen hole for screen printing, the screen hole shape is a square, and the size of the screen hole is greater than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially overlaid on the black dot-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0062] (6) The single crystal diamond seed crystal after the second screen printing is placed in an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0063] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0064] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0065] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccmm, pressure 8KPa, temperature 500℃, etching time 120min;

[0066] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0067] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen blowing;

[0068] (9) Growth:

[0069] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0070] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0071] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, and the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ and at a speed of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until room temperature, the microwave is turned off, the hydrogen is stopped, and a single crystal diamond is obtained.

[0072] Example 3

[0073] The present embodiment provides a high-quality single crystal diamond preparation method for removing polycrystalline defects, as shown in Figure 1As shown, comprising the following steps:

[0074] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 5g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black point-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal;

[0075] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at 80℃ for 60min, and is dried;

[0076] (3) The dried single crystal diamond seed crystal is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching, specifically:

[0077] S31. First oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0078] S32. First plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 5:3:2, the pressure is 8KPa, the temperature is 500℃, and the etching time is 120min;

[0079] S33. First plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0080] (4) Cleaning: the single crystal diamond seed crystal after step (3) etching is put into aqua regia solution, cleaned for 10min, then sequentially cleaned with deionized water, acetone, anhydrous ethanol, deionized water for 10min, and dried with nitrogen;

[0081] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 5g of iron oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal of step (4) is placed under the screen plate, the black point-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0082] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at 100℃ for 60min, and is dried;

[0083] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0084] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0085] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 8KPa, temperature 500℃, etching time 120min;

[0086] S73. Second plasma etching: argon 197sccm, oxygen 3sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0087] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, deionized water for 10min, and dried with nitrogen;

[0088] (9) Growth:

[0089] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0090] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0091] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, and the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until the temperature reaches room temperature, the microwave is turned off, and the hydrogen is stopped, to obtain a single crystal diamond.

[0092] Example 4

[0093] The present embodiment provides a high-quality single crystal diamond preparation method for removing polycrystal defects, as shown in Figure 1As shown, comprising the following steps:

[0094] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black point-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal;

[0095] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at 100℃ for 60min, and is dried;

[0096] (3) The dried single crystal diamond seed crystal is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching, specifically:

[0097] S31. First oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0098] S32. First plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 8:3:2, the pressure is 8KPa, the temperature is 500℃, and the etching time is 120min;

[0099] S33. First plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0100] (4) Cleaning: the single crystal diamond seed crystal after step (3) etching is put into aqua regia solution, cleaned for 10min, then sequentially cleaned with deionized water, acetone, anhydrous ethanol, deionized water for 10min, and dried with nitrogen;

[0101] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of iron oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal of step (4) is placed under the screen plate, the black point-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0102] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at 100℃ for 60min, and is dried;

[0103] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0104] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0105] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 8KPa, temperature 500℃, etching time 120min;

[0106] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0107] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, deionized water for 10min, and dried with nitrogen;

[0108] (9) Growth:

[0109] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0110] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0111] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until the temperature reaches room temperature, the microwave is turned off, and the hydrogen is stopped, to obtain a single crystal diamond.

[0112] Example 5

[0113] The present embodiment provides a high-quality single crystal diamond preparation method for removing polycrystal defects, as shown in Figure 1As shown, comprising the following steps:

[0114] (1) 6 g of pine oil alcohol, 2 g of butyl carbitol acetate, 2 g of dibutyl phthalate, 3 g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black point-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal;

[0115] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at 100℃ for 60 min for drying;

[0116] (3) The dried single crystal diamond seed crystal is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching, specifically:

[0117] S31. First oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0118] S32. First plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 5:3:2, the pressure is 15KPa, the temperature is 900℃, and the etching time is 120min;

[0119] S33. First plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0120] (4) Cleaning: the single crystal diamond seed crystal after etching in step (3) is put into aqua regia solution and cleaned for 10 min, then sequentially cleaned with deionized water, acetone, anhydrous ethanol and deionized water for 10 min, and dried with nitrogen;

[0121] (5) 6 g of pine oil alcohol, 2 g of butyl carbitol acetate, 2 g of dibutyl phthalate, 3 g of iron oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal in step (4) is placed under the screen plate, and the black point-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0122] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at 100℃ for 60 min for drying;

[0123] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0124] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0125] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 15KPa, temperature 900℃, etching time 120min;

[0126] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0127] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen;

[0128] (9) Growth:

[0129] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0130] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0131] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until room temperature, the microwave is turned off, the hydrogen is stopped, and a single crystal diamond is obtained.

[0132] Comparative Example 1

[0133] The present comparative example provides a method for preparing high-quality single crystal diamond with removal of polycrystalline defects, comprising the following steps:

[0134] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 0.5g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black dot-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black dot-shaped polycrystal of the single crystal diamond seed crystal;

[0135] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at 100℃ for 60min, and is dried;

[0136] (3) The dried single crystal diamond seed crystal is sequentially subjected to the first oxygen etching, the first plasma and metal active catalytic etching, and the first plasma etching, specifically:

[0137] S31. The first oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 10min;

[0138] S32. The first plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 5:3:2, the pressure is 8KPa, the temperature is 500℃, and the etching time is 120min;

[0139] S33. The first plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0140] (4) Cleaning: the single crystal diamond seed crystal after step (3) etching is put into aqua regia solution, cleaned for 10min, then sequentially cleaned with deionized water, acetone, anhydrous ethanol, deionized water for 10min, and dried with nitrogen;

[0141] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of iron oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal of step (4) is placed under the screen plate, the black dot-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black dot-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0142] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at 100℃ for 60min, and is dried;

[0143] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0144] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0145] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 8KPa, temperature 500℃, etching time 120min;

[0146] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0147] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen;

[0148] (9) Growth:

[0149] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0150] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0151] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until room temperature, the microwave is turned off, the hydrogen is stopped, and a single crystal diamond is obtained.

[0152] Comparative Example 2

[0153] The present comparative example provides a method for preparing high-quality single crystal diamond with removed polycrystalline defects, comprising the following steps:

[0154] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black dot-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black dot-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0155] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0156] (3) The dried single crystal diamond seed crystal is sequentially subjected to the first oxygen etching, the first plasma and metal active catalytic etching, and the first plasma etching, specifically:

[0157] S31. The first oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0158] S32. The first plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 10:3:2, the pressure is 16KPa, the temperature is 1000℃, and the etching time is 120min;

[0159] S33. The first plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0160] (4) Cleaning: the single crystal diamond seed crystal after the etching of step (3) is put into aqua regia solution, and is cleaned for 10min, and then is sequentially ultrasonically cleaned with deionized water, acetone, anhydrous ethanol and deionized water for 10min, and is dried with nitrogen blowing;

[0161] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of iron oxide powder are configured into an organic slurry, the single crystal diamond seed crystal after the cleaning of step (4) is placed under the screen plate, the black dot-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black dot-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0162] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0163] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0164] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0165] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 8KPa, temperature 500℃, etching time 120min;

[0166] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0167] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen;

[0168] (9) Growth:

[0169] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0170] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0171] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until room temperature, the microwave is turned off, the hydrogen is stopped, and a single crystal diamond is obtained.

[0172] Comparative Example 3

[0173] The present comparative example provides a method for preparing high-quality single crystal diamond with removal of polycrystalline defects, comprising the following steps:

[0174] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, and 3g of cerium oxide powder are configured into an organic slurry, a single crystal diamond seed crystal after cleaning is placed under a screen plate, and a black dot-shaped polycrystal of the single crystal diamond seed crystal is aligned with a screen hole for first screen printing, the screen hole shape is a square, and the size of the screen hole is greater than that of the black dot-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially overlaid on the black dot-shaped polycrystal of the single crystal diamond seed crystal;

[0175] (2) The single crystal diamond after the first screen printing is placed in an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0176] (3) The single crystal diamond seed crystal after drying is sequentially subjected to first oxygen etching, first plasma and metal active catalytic etching, and first plasma etching, specifically:

[0177] S31. First oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0178] S32. First plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen, and argon, the volume ratio is 3:3:2, the pressure is 7KPa, the temperature is 400℃, and the etching time is 120min;

[0179] S33. First plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0180] (4) Cleaning: the single crystal diamond seed crystal after etching in step (3) is placed in aqua regia solution, and is cleaned for 10min, and then is sequentially ultrasonically cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and is dried with nitrogen blowing;

[0181] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, and 3g of iron oxide powder are configured into an organic slurry, the single crystal diamond seed crystal after cleaning in step (4) is placed under a screen plate, and a black dot-shaped polycrystal is aligned with a screen hole for screen printing, the screen hole shape is a square, the size of the screen hole is greater than that of the black dot-shaped polycrystal, and the size of the screen hole is smaller than that of the first screen printing, and a layer of square organic slurry with a thickness of 5 microns is sequentially overlaid on the black dot-shaped polycrystal of the single crystal diamond seed crystal after the first screen printing;

[0182] (6) The single crystal diamond seed crystal after the second screen printing is placed in an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0183] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0184] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0185] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 7KPa, temperature 400℃, etching time 120min;

[0186] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0187] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen;

[0188] (9) Growth:

[0189] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0190] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0191] (10) When the growth is completed, the introduction of methane, carbon dioxide, argon, and nitrogen is stopped, the temperature rising speed is set to 5℃ / min, the temperature is raised to 1300℃, the temperature is kept for 1h, then the temperature is lowered at a gradient of 200℃ at a rate of 2℃ / min, and the temperature is kept for 1h at each gradient temperature, until room temperature, the microwave is turned off, the hydrogen is stopped, and a single crystal diamond is obtained.

[0192] Comparative Example 4

[0193] The present comparative example provides a method for preparing high-quality single crystal diamond with removed polycrystalline defects, comprising the following steps:

[0194] (1) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of cerium oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal is placed under the screen plate, the black point-shaped polycrystal of the single crystal diamond seed crystal is aligned with the screen hole for the first time screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0195] (2) The single crystal diamond after the first screen printing is put into an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0196] (3) The dried single crystal diamond seed crystal is sequentially subjected to the first oxygen etching, the first plasma and metal active catalytic etching, and the first plasma etching, specifically:

[0197] S31. The first oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0198] S32. The first plasma and metal active catalytic etching: the atmosphere is a mixed atmosphere of hydrogen, nitrogen and argon, the volume ratio is 5:3:2, the pressure is 8KPa, the temperature is 500℃, and the etching time is 120min;

[0199] S33. The first plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0200] (4) Cleaning: the single crystal diamond seed crystal after the etching of step (3) is put into aqua regia solution, and is cleaned for 10min, and then is sequentially ultrasonically cleaned with deionized water, acetone, anhydrous ethanol and deionized water for 10min, and is dried with nitrogen;

[0201] (5) 6g of pine oil alcohol, 2g of butyl carbitol acetate, 2g of dibutyl phthalate, 3g of iron oxide powder are configured into an organic slurry, the cleaned single crystal diamond seed crystal of step (4) is placed under the screen plate, the black point-shaped polycrystal is aligned with the screen hole for screen printing, the screen hole shape is square, the size of the screen hole is larger than that of the black point-shaped polycrystal, and a layer of square organic slurry with a thickness of 5 microns is sequentially covered on the black point-shaped polycrystal of the single crystal diamond seed crystal which has been subjected to the first screen printing;

[0202] (6) The single crystal diamond seed crystal after the second screen printing is put into an oven, and is kept at a temperature of 100℃ for 60min, and is dried;

[0203] (7) The dried single crystal diamond seed crystal is sequentially subjected to second oxygen etching, second plasma and metal active catalytic etching, and second plasma etching, specifically:

[0204] S71. Second oxygen etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0205] S72. Second plasma and metal active catalytic etching: hydrogen 200sccm, argon 40sccm, pressure 16KPa, temperature 1100℃, etching time 120min;

[0206] S73. Second plasma etching: oxygen 3sccm, argon 197sccm, pressure 5KPa, temperature 200℃, etching time 5min;

[0207] (8) Cleaning: the single crystal diamond seed crystal etched in step (8) is placed in aqua regia solution and cleaned for 10min, and then sequentially cleaned with deionized water, acetone, anhydrous ethanol, and deionized water for 10min, and dried with nitrogen blowing;

[0208] (9) Growth:

[0209] S91. The seed crystal cleaned in step (8) is placed in the grid groove of the substrate table, and then the substrate table is placed in the deposition cavity, the cavity pressure is pumped to below 0.8Pa, the hydrogen valve is opened, the hydrogen flow value is set to 400sccm, when the pressure rises to 1kPa, the microwave is turned on, the microwave power is set to 600W, the temperature rising speed is set to 10℃ / min, and the temperature is raised to 900℃, the pressure rises to 17KPa, and etching is performed for 30min;

[0210] S92. After etching is completed, methane, carbon dioxide, argon, and nitrogen are introduced, the methane flow value is set to 32sccm, the carbon dioxide flow value is set to 2sccm, the argon flow value is set to 10sccm, the nitrogen flow value is set to 0.1sccm, the pressure is set to 20kPa, the temperature is kept at 950℃, and growth is performed for 180h;

[0211] (10) When the growth is completed, stop introducing methane, carbon dioxide, argon, and nitrogen, set the temperature rising speed to 5℃ / min, raise the temperature to 1300℃, keep the temperature for 1h, then reduce the temperature at a gradient of 200℃ at a rate of 2℃ / min, keep the temperature at each gradient for 1h, and cool to room temperature, turn off the microwave, and stop introducing hydrogen, to obtain a single crystal diamond.

[0212] The growth process of the single crystal diamond of Examples 3-5 and Comparative Examples 1-4 was detected, and the results are shown in Table 1. From the experimental data table, it can be seen that the growth defects can be well removed by using the method of the present application, and the single crystal diamond with good quality is obtained.

[0213] Table 1

[0214]

[0215] The above only is the preferred embodiment of the present application, and is not used to limit the present application, for the person skilled in the art, the present application can have various changes and variations. Within the spirit and principles of the present application.

Claims

1. A method for producing high-quality single-crystal diamond free from poly-crystal defects, characterized by, The method comprises the following steps: (1) configuring terpineol, butyl carbitol acetate, dibutyl phthalate and cerium oxide powder into an organic slurry according to a mass ratio of 4-8:1-3:1-3:3-5; placing the cleaned single crystal diamond seed crystal under a screen plate, and performing first screen printing on the black point-shaped polycrystal of the single crystal diamond seed crystal by aligning the screen hole; the screen hole is square, and the size of the screen hole is larger than that of the black point-shaped polycrystal; and then covering the black point-shaped polycrystal of the single crystal diamond seed crystal with an organic slurry layer with a thickness of 2-5 microns; (2) drying the single crystal diamond seed crystal after the first screen printing; (3) sequentially performing first oxygen etching, first plasma and metal active catalytic etching and first plasma etching on the dried single crystal diamond seed crystal to obtain the single crystal diamond seed crystal after the first etching; (4) cleaning the single crystal diamond seed crystal after the first etching and blowing dry; (5) configuring terpineol, butyl carbitol acetate, dibutyl phthalate and iron oxide or nickel oxide into an organic slurry according to a mass ratio of 4-8:1-3:1-3:3-5; placing the single crystal diamond seed crystal treated in step (4) under a screen plate, and performing screen printing on the black point-shaped polycrystal by aligning the screen hole; the size of the screen hole is larger than that of the black point-shaped polycrystal, and the size of the screen hole is smaller than that of the screen hole in the first screen printing; and then covering the black point-shaped polycrystal of the single crystal diamond seed crystal after the first screen printing with an organic slurry layer with a thickness of 2-5 microns; (6) drying the single crystal diamond seed crystal after the second screen printing; (7) sequentially performing second oxygen etching, second plasma and metal active catalytic etching and second plasma etching on the dried single crystal diamond seed crystal to obtain the single crystal diamond seed crystal after the second etching; (8) cleaning the single crystal diamond seed crystal after the second etching and blowing dry; (9) sequentially performing etching and growth on the seed crystal treated in step (8); (10) after the growth is completed, increasing the temperature by 100-150 DEG C on the basis of the growth temperature in step (9), keeping warm for 1-2 h, and then cooling to room temperature to obtain the single crystal diamond; In step (3), the first oxygen etching is performed in an atmosphere of at least one of oxygen, argon and air, at a pressure of 5-10 KPa, at a temperature of 200-500 DEG C, and for 5-10 min; The first plasma and metal active catalytic etching is performed in a mixed atmosphere of hydrogen, nitrogen and argon at a volume ratio of 5-8:3:2, at a pressure of 8-15 KPa, at a temperature of 500-900 DEG C, and for 10-120 min; The first plasma etching is performed in an atmosphere of at least one of oxygen, argon, nitrogen, air and carbon monoxide, at a pressure of 5-10 KPa, at a temperature of 200-500 DEG C, and for 5-40 min; In step (7), the second oxygen etching is performed in an atmosphere of at least one of oxygen, argon and air, at a pressure of 5-10 KPa, at a temperature of 200-500 DEG C, and for 5-10 min; ​ ​ S72. The second plasma and metal active catalytic etching: the atmosphere is at least one of hydrogen, carbon monoxide, argon, helium, the pressure is 8-15 KPa, the temperature is 500-900 ℃, and the etching time is 10-120 min; S73. The second plasma etching: the atmosphere is at least one of oxygen, argon, nitrogen, air, carbon monoxide, the pressure is 5-10 KPa, the temperature is 200-500 ℃, and the etching time is 5-40 min.

2. The production method according to claim 1, wherein Step (4) or (8) is specifically: put the single crystal diamond seed crystal into aqua regia solution, and clean for 3-10 min; then sequentially clean with deionized water, acetone, anhydrous ethanol, and deionized water for 5-10 min, and dry with nitrogen.

3. The production method according to claim 1, wherein Step (9) is specifically: S91. Put the seed crystal cleaned in step (8) into the substrate table, and then put the substrate table into the deposition cavity, and after vacuumizing, start to input hydrogen, and start the microwave, and etch for 0.5-2 h at a temperature of 700-1000 ℃ and a pressure of 17-21 kPa; S92. After etching is completed, input methane, carbon dioxide, argon, and nitrogen, and grow for 180-200 h in an environment with a pressure of 20-24 kPa and a temperature of 900-1050 ℃.

4. The production method according to claim 3, wherein Step (10) is specifically: after growth is completed, stop inputting methane, carbon dioxide, argon, and nitrogen, increase the temperature by 100-150 ℃ based on the growth temperature in step (9), and keep warm for 1-2 h, then decrease the temperature by 100-200 ℃ as a gradient, and keep warm for 1-2 h at each gradient temperature, and then decrease to room temperature, and then stop the microwave and the input of hydrogen, and obtain the single crystal diamond.

5. The production method according to claim 3, wherein In step (9), the substrate table comprises a substrate table main body in a cylindrical structure or a circular table structure, a circular groove is arranged on the upper surface of the substrate table main body, and a plurality of grid grooves for accommodating seed crystals are arranged at the bottom of the circular groove. The width of the grid groove is 0.15-0.5 mm larger than the width of the seed crystal, the depth of the grid groove is 0.05-0.15 mm smaller than the thickness of the seed crystal, and the limiting step width between two grids is 0.9-1.5 mm; the diameter of the circular groove is 1-3 mm smaller than the diameter of the upper surface of the substrate table, and the depth of the circular groove is 0.5-1 mm larger than the difference between the thickness of the seed crystal and the depth of the grid groove.

6. The production method according to claim 5, wherein The center of the circular groove coincides with the center of the surface of the substrate table main body.

7. The production method according to claim 5, wherein The seed crystal is in a square columnar structure, and the grid groove is in a square columnar hollow structure.

8. The substrate table of claim 5, wherein, The grid grooves are uniformly arranged on the upper surface of the substrate table main body; the grid grooves are arranged in any one of the following arrangement modes on the upper surface of the substrate table main body: a plurality of linear arrays, a plurality of circular peripheral arrays, and a plurality of rectangular arrays; the distance between adjacent grid grooves is 0.9-1.5 mm; and the adjacent grid grooves are in communication with each other.

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