Diamond single crystal growth method and growth device based on top-seed solution method

Abstract

The present application belongs to the technical field of diamond single crystal preparation, and particularly relates to a diamond single crystal growth method and a growth device based on a top seed solution method, which comprises the following steps: S1, preparation of a cosolvent: a cosolvent is prepared according to a ternary system A-B-C, and the prepared cosolvent raw material and a carbon source are loaded into a growth container; S2, temperature rising and melting: the growth container is sealed, vacuumized, and then filled with a protective gas, the cosolvent raw material is heated to be melted, and the carbon source is fully dissolved at a constant temperature to obtain a carbon-saturated solution; S3, seed crystal installation and descending contact: the seed crystal is fixed at the bottom of a seed crystal holder, and the seed crystal is driven to descend to be in contact with or immersed in the carbon-saturated solution; S4, plasma-assisted crystal growth: a plasma gas flow is introduced into the growth container, the growth container is rotated, and diamond crystallization growth is performed on the surface of the seed crystal; and S5, temperature reduction and crystal taking: after the growth is completed, the crystal is separated from the liquid surface by lifting the seed crystal, and the diamond single crystal is obtained after slow cooling and taking out.

Description

Technical Field

[0001] This invention belongs to the field of diamond single crystal preparation technology, specifically relating to a diamond single crystal growth method and growth apparatus based on the top seed crystal solution method. Background Technology

[0002] Diamond, as a typical representative of ultra-wide bandgap semiconductor materials, has the characteristics of large bandgap (5.5 eV), high carrier mobility, extremely high thermal conductivity (2000 W / (m·K)), high breakdown electric field strength, and excellent radiation resistance. It has broad application prospects in high-power power electronic devices, quantum chips, radio frequency devices, and high-end heat dissipation substrates. It is considered to be the fourth generation of semiconductor materials after silicon (Si), gallium arsenide (GaAs), silicon carbide (SiC), and gallium nitride (GaN).

[0003] Currently, the mainstream technologies for the artificial synthesis of diamond single crystals include the High Temperature High Pressure (HTHP) method and the Microwave Plasma Chemical Vapor Deposition (MPCVD) method. (1) High Temperature High Pressure (HTHP): This technology simulates the high temperature and high pressure growth environment of natural diamond. Under the catalytic action of metal catalysts such as Fe, Ni, and Co, graphite is transformed into diamond under high pressure of 5-6 GPa and high temperature of 1300-1600℃. Although the growth rate of HTHP is relatively fast, the diamond single crystal size prepared is usually less than 10 mm due to the limitation of high pressure equipment. Moreover, due to the introduction of metal catalysts, metal impurities and inclusions are inevitably present in the crystal, which seriously affects the crystal quality. In addition, high pressure equipment is expensive and energy-intensive, making it difficult to achieve large-scale production of large-size wafers.

[0004] (2) Microwave Plasma Chemical Vapor Deposition (MPCVD): This technique uses CH4 and H2 as gas sources to epitaxially grow diamond single crystals on diamond seed crystals in a microwave-excited plasma environment at a temperature of 800-1000℃ and atmospheric pressure. MPCVD can produce high-purity, large-area diamond films and self-supporting diamond single crystal wafers, and is currently the main method for preparing electronic-grade diamond single crystals. However, MPCVD also has problems such as growth rates below 10 μm / h, expensive equipment, high cost of gas raw materials, and difficulty in controlling large-area uniformity, which limit its widespread application in the industrial field.

[0005] Compared with the two methods mentioned above, the atmospheric pressure liquid phase method (solution method) for growing diamond single crystals has potential advantages such as relatively low growth temperature, low gas pressure, stable growth environment, lower equipment cost, and ease of achieving large-area growth, and has received widespread attention from researchers in recent years. Top seed solution method (TSSG) is an important form of liquid phase method. Its principle is to dissolve the carbon source in a metal flux to form a supersaturated solution, then immerse the diamond seed crystal in the solution, and control the temperature gradient to cause carbon to precipitate on the surface of the seed crystal and epitaxially grow into a diamond single crystal.

[0006] However, existing liquid-phase diamond growth technologies still face the following technical bottlenecks: carbon has low solubility in metal solutions and is mainly distributed as sp(s). 2 Hybrid forms are predominant, making it difficult to achieve sp 3 The transformation of the hybrid diamond structure is mainly due to the carbon-to-sp conversion. 3 The high energy barrier and insufficient driving force of hybrid structure transition directly lead to difficulties in diamond nucleation, slow growth rate, and crystal quality that is difficult to meet the requirements of electronic device applications.

[0007] Therefore, overcoming the shortcomings of insufficient solubility and conversion efficiency of carbon in metal solutions is a technical problem that urgently needs to be solved in this field.

[0008] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0009] This disclosure provides at least one method and apparatus for diamond single crystal growth based on the top seed crystal solution method.

[0010] In a first aspect, embodiments of this disclosure provide a method for growing diamond single crystals based on a top-seeded solution method, comprising the following steps: S1, flux preparation: A flux is prepared according to an ABC ternary system; the prepared flux raw materials and carbon source are loaded into a growth container, wherein component A is any one or more of low-melting-point metals Ga, In, Sn, and Cu; component B is any one or more of carbon-soluble metals Fe, Co, Ni, and Mn; and component C is sp... 3S2, Heating and Melting: Seal the growth container, evacuate it, fill it with a protective gas, heat it to melt the co-solvent material, and keep it at a constant temperature to fully dissolve the carbon source to obtain a carbon-saturated solution; S3, Seed Crystal Installation and Lowering Contact: Fix the seed crystal at the bottom of the seed crystal holder, and lower the seed crystal to contact or immerse it in the carbon-saturated solution; S4, Plasma-Assisted Crystal Growth: Introduce a plasma gas flow into the growth container, rotate the growth container, and perform diamond crystal growth on the surface of the seed crystal. During the growth process, maintain the temperature of the seed crystal below 1200°C and keep the temperature of the carbon-saturated solution higher than the temperature of the seed crystal; S5, Cooling and Crystal Removal: After the growth is completed, lift the seed crystal to remove it from the liquid surface, slowly cool it down, and then remove it to obtain a diamond single crystal.

[0011] In one optional embodiment, the cosolvent raw material contains component A at a mass percentage of 50% to 90%, component B at a mass percentage of 5% to 40%, and component C at a mass percentage of 0.1% to 15%.

[0012] In one optional embodiment, in step S2, the growth container is a graphite crucible, and the heating temperature is 800-1200℃, with a constant temperature time of 1-10h.

[0013] In one optional embodiment, in step S3, the seed crystal includes any one of silicon carbide single crystal, diamond single crystal, boron nitride single crystal, silicon-based diamond composite substrate, silicon-based boron nitride composite substrate, sapphire-based diamond composite substrate, and sapphire-based boron nitride composite substrate.

[0014] In one optional embodiment, in step S4, the plasma gas flow includes H2 and CH4, wherein CH4 accounts for 1 to 20% of the total volume percentage of the plasma gas flow; and the total flow rate of the plasma gas flow is 50 to 1000 sccm.

[0015] In one optional embodiment, in step S4, the rotating growth container specifically includes: simultaneously starting the seed crystal rotation and the growth container rotation; the rotation speed of the seed crystal is 1 to 100 rpm, the rotation speed of the growth container is 1 to 100 rpm, and the rotation directions of the seed crystal and the growth container are opposite.

[0016] Secondly, embodiments of this disclosure also provide a diamond single crystal growth apparatus based on the top seed solution method, comprising: a furnace body, wherein a growth container and a heating assembly are disposed within the furnace body, the heating assembly being disposed around and / or on top of the growth container; a growth container lifting mechanism and a growth container rotating mechanism are connected to the bottom of the growth container through the lower opening of the furnace body; a seed crystal lifting and rotating assembly, comprising a seed crystal rod and a seed crystal holder disposed at the bottom end of the seed crystal rod, the seed crystal rod passing through the upper opening of the furnace body; wherein a seed crystal is fixed at the bottom of the seed crystal holder, and the seed crystal lifting mechanism and the seed crystal rotating mechanism are connected to the top of the seed crystal rod; a temperature control system for controlling the temperature of the solution in the growth container and the temperature of the seed crystal; and a plasma gas path assembly, comprising a gas supply source, a plasma generator, and a gas conduit, the gas conduit extending through the furnace body to the growth container and supplying a plasma gas flow ionized by the plasma generator from the gas supply source.

[0017] In one alternative embodiment, the growth container is a graphite crucible made of isostatically pressed graphite material.

[0018] In one alternative implementation, the plasma generator is a plasma torch or a radio frequency plasma device.

[0019] In one alternative embodiment, the gas conduit delivers the plasma gas flow to the surface of the solution near the seed crystal or immerses it in the solution.

[0020] The beneficial effect of this invention is that the diamond single crystal growth method and growth apparatus based on the top seed crystal solution method adopts an ABC ternary flux system, through a low melting point metal, a carbon-soluble metal, and sp... 3 The synergistic effect of hybrid framework agents achieves high carbon solubility and sp. 3 The effective promotion of the hybrid diamond phase solves the problems of low carbon solubility and sp in traditional liquid-phase methods. 3 Technical challenges related to insufficient hybridization driving force.

[0021] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the overall structure of the top seed crystal solution method diamond single crystal growth apparatus provided in this embodiment of the disclosure; Figure 2 A partial cross-sectional view of the growth container and heating assembly in the growth apparatus provided in an embodiment of this disclosure; Figure 3 This is a schematic diagram of the plasma gas path assembly in the growth apparatus provided in an embodiment of the present disclosure; Figure 4 A partially enlarged view of the seed crystal pulling and rotating assembly provided in an embodiment of this disclosure; Figure 5 This is a partially enlarged view of the growth container lifting and rotating assembly provided in an embodiment of this disclosure.

[0025] In the picture: 1. Furnace body; 2. Growth container; 3. Seed crystal rod; 31. Seed crystal holder; 4. Heating assembly; 51. Growth container lifting mechanism; 52. Growth container rotation mechanism; 61. Seed crystal lifting mechanism; 62. Seed crystal rotation mechanism; 71. Gas supply source; 72. Plasma generator; 73. Gas conduit. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] This disclosure provides a method for diamond single crystal growth based on the top seed solution method, including the following steps: S1, flux preparation: Prepare the flux according to the ABC ternary system, and load the prepared flux raw materials and carbon source into the growth container, wherein component A is any one or more of low-melting-point metals Ga, In, Sn, and Cu, component B is any one or more of carbon-soluble metals Fe, Co, Ni, and Mn, and component C is sp 3 S2, Heating and Melting: Seal the growth container, evacuate it, fill it with a protective gas, heat it to melt the co-solvent material, and keep it at a constant temperature to fully dissolve the carbon source to obtain a carbon-saturated solution; S3, Seed Crystal Installation and Lowering Contact: Fix the seed crystal at the bottom of the seed crystal holder, and lower the seed crystal to contact or immerse it in the carbon-saturated solution; S4, Plasma-Assisted Crystal Growth: Introduce a plasma gas flow into the growth container, rotate the growth container, and perform diamond crystal growth on the surface of the seed crystal. During the growth process, maintain the temperature of the seed crystal below 1200°C and make the temperature of the carbon-saturated solution higher than the temperature of the seed crystal to form a temperature gradient; S5, Cooling and Crystal Removal: After the growth is completed, lift the seed crystal to remove it from the liquid surface, slowly cool it down, and then remove it to obtain a diamond single crystal.

[0031] Specifically, the diamond growth mechanism in this invention is as follows: sp in solid carbon sources 2Hybridized graphite dissolves in liquid metal containing component B, forming a carbon-containing metal solution. In the solution, carbon atoms mainly exist in sp... 2 Hybrid planar structures exist. When the solution is transported to the vicinity of the seed crystal, a localized supercooled region is formed because the seed crystal temperature is lower than the bulk solution temperature, and carbon reaches a supersaturated state near the seed crystal.

[0032] At this point, component C in the solution forms sp on the surface of the seed crystal. 3 The hybrid coordination network structure provides a template for the rearrangement of carbon atoms. Simultaneously, the active hydrogen atoms H in the introduced plasma-enhanced H2 gas flow... * With sp in solution 2 The carbon reaction forms CH bonds at the seed crystal surface and solution interface. The introduction of CH bonds alters the coordination environment of carbon atoms, inducing carbon atoms to move from sp... 2 Hybridization towards sp 3 Hybridization transition.

[0033] High supersaturation on the seed crystal surface, sp 3 Under the combined effect of the template effect of the hybrid framework agent and the CH bond formation induced by ionized H atoms, carbon atoms are arranged in an orderly manner on the seed crystal surface according to the tetrahedral structure of diamond, thus realizing the crystallization growth of the diamond structure.

[0034] In some embodiments, specifically, in the cosolvent raw material, the mass percentage content of component A is 50% to 90%, the mass percentage content of component B is 5% to 40%, and the mass percentage content of component C is 0.1% to 15%.

[0035] Specifically, component A, as the main matrix of the co-solvent, provides a low-melting-point liquid phase environment, lowers the growth temperature, and facilitates carbon diffusion and transport; component B has good carbon solubility, significantly improving the solubility and dissolution rate of carbon in solution; component C forms sp in solution. 3 The hybrid coordination structure serves as a template and catalyst for carbon atoms to arrange themselves into a diamond structure, promoting sp... 2 Hybridized carbon to sp 3 Transformation of hybrid diamond structure.

[0036] In some embodiments, specifically in step S2, the growth container is a graphite crucible, and the heating temperature is 800–1200°C, with a constant temperature time of 1–10 h.

[0037] In some embodiments, specifically in step S3, the seed crystal includes any one of silicon carbide single crystal, diamond single crystal, boron nitride single crystal, silicon-based diamond composite substrate, silicon-based boron nitride composite substrate, sapphire-based diamond composite substrate, and sapphire-based boron nitride composite substrate. The seed crystal has a tetrahedral crystal structure, which has a high degree of matching with the diamond lattice and is beneficial to the epitaxial growth of diamond.

[0038] In some embodiments, specifically in step S4, the plasma gas flow includes H2 and CH4, wherein CH4 accounts for 1 to 20% of the total volume percentage of the plasma gas flow; and the total flow rate of the plasma gas flow is 50 to 1000 sccm.

[0039] Specifically, in step S4, the seed crystal temperature is strictly controlled below 1200℃, which mainly plays a role in stabilizing the liquid phase and diamond phase regions in the multi-phase diagram and preventing the appearance of solid phases other than the diamond phase, such as silicon carbide, in the solution.

[0040] Specifically, the growth container uses a graphite crucible as a solid carbon source, with carbon supplied by dissolution from the inner wall of the graphite crucible. At the growth temperature, the carbon in the graphite crucible gradually dissolves into the co-solvent solution, forming a carbon-saturated or supersaturated solution. CH4 in the plasma gas flow serves as a gaseous carbon source. CH4 is ionized in the plasma to generate active carbon-containing groups, which are directly transported to the vicinity of the seed crystal growth interface to supplement the lack of solid carbon source. The above dual carbon source supply strategy ensures a continuous and sufficient supply of carbon source during the growth process, avoiding growth interruption or crystal defects caused by carbon source depletion.

[0041] In some embodiments, specifically in step S4, the rotating growth container specifically includes: simultaneously starting the seed crystal rotation and the growth container rotation; the rotation speed of the seed crystal is 1 to 100 rpm, the rotation speed of the growth container is 1 to 100 rpm, and the rotation direction of the seed crystal and the growth container is opposite.

[0042] Specifically, the TSSG method for growing diamond provided by this invention has a lower growth temperature than the HTHP method, significantly reducing equipment costs. It also eliminates the need for high-pressure conditions, ensuring good safety and facilitating large-scale production. Compared with the MPCVD method, this invention offers higher growth rates, lower gas consumption, and better large-area uniformity, resulting in significant cost advantages.

[0043] Specifically, the diamond single crystal prepared by this invention can be used in high-end application fields such as high-power electronic devices, quantum sensors, radio frequency devices, and heat dissipation substrates, providing technical support for the industrial application of diamond.

[0044] Please see Figure 1This disclosure also provides a diamond single crystal growth apparatus based on the top seed solution method, comprising: a furnace body 1, as shown in the embodiment. Figure 2 As shown, a growth container 2 and a heating assembly 4 are disposed inside the furnace body 1. The heating assembly 4 is disposed around and / or on top of the growth container 2. The bottom of the growth container 2 is connected to a [connector name missing] through the lower opening of the furnace body 1. Figure 5 The growth container lifting mechanism 51 and the growth container rotating mechanism 52 are described above; the seed crystal lifting and rotating assembly includes a seed crystal rod 3 and a seed crystal holder 31 disposed at the bottom end of the seed crystal rod 3, wherein the seed crystal rod 3 passes through the upper opening of the furnace body 1; wherein a seed crystal is fixed at the bottom of the seed crystal holder 31, and the top of the seed crystal rod 3 is connected to a... Figure 4 The seed crystal lifting mechanism 61 and seed crystal rotating mechanism 62 are shown; a temperature control system is used to control the temperature of the solution in the growth container 2 and the temperature of the seed crystal; and, as shown... Figure 3 The plasma gas path assembly shown includes a gas supply source 71, a plasma generator 72, and a gas conduit 73. The gas conduit 73 extends through the furnace body 1 to the growth container 2 and is supplied with a plasma gas flow that has been ionized by the plasma generator 72 from the gas supply source 71.

[0045] In some embodiments, specifically, the growth container 2 is a graphite crucible, which is made of isostatically pressed graphite material. Preferably, an ABC stacked rhombic graphite crucible is used as the solid carbon source and growth container. Rhombic graphite has higher reactivity and dissolution rate, which is beneficial for providing sufficient carbon source. At the same time, the use of isostatically pressed graphite material ensures the structural stability and long life of the crucible in the high-temperature solution environment.

[0046] In some embodiments, specifically, the plasma generator 72 is a plasma torch or a radio frequency plasma device.

[0047] Specifically, integrating a plasma gas path component into a conventional liquid-phase single-crystal furnace introduces a plasma-enhanced H2 and CH4 mixture. This provides an additional gaseous carbon source and, on the other hand, the active hydrogen atoms promote sp... 2 To sp 3 The hybridization transformation significantly improved the diamond growth rate and crystal quality.

[0048] In some embodiments, specifically, the gas conduit 73 delivers the plasma gas flow to the surface of the solution near the seed crystal or immerses it in the solution.

[0049] Example 1: Diamond single crystal growth was performed using the top seed solution method diamond single crystal growth apparatus of the present invention. The specific steps are as follows: S1, preparation of flux: Weigh 60g of metallic Ga as component A, 25g of metallic Fe and 10g of metallic Co as component B, and 5g of metallic Si as component C. Mix the above raw materials evenly and put them into an isostatically pressed rhombic graphite crucible with an inner diameter of 60mm.

[0050] S2, Heating and Melting: Seal the furnace and evacuate to 10°C. -3 After Pa, high-purity argon gas is introduced as a protective atmosphere. The heating components are started, and the raw material is heated to 950°C at a heating rate of 5°C / min. The temperature is maintained for 3 hours to completely melt the raw material and fully dissolve the carbon in the graphite crucible.

[0051] S3, Seed Crystal Installation and Inoculation: Select a 5mm×5mm high-temperature high-pressure (HTHP) diamond single crystal as the seed crystal and fix it to the bottom of the molybdenum seed crystal holder. Start the seed crystal lifting and rotating assembly to lower the seed crystal to a position 2mm above the liquid surface and preheat for 10 minutes, then continue lowering it until the seed crystal contacts the solution surface.

[0052] S4, Plasma-Assisted Crystal Growth: The plasma gas path assembly is activated, and a mixture of H2 and CH4 gas is introduced. The CH4 volume fraction is set to 5%, and the total plasma gas flow rate is 200 sccm. After ionization by the radio frequency plasma generator, the plasma gas flow is delivered above the seed crystal. The seed crystal temperature is set to 850℃, the bulk solution temperature to 900℃, the seed crystal rotation speed to 20 rpm (clockwise), the graphite crucible rotation speed to 10 rpm (counterclockwise), and the growth time to 48 hours.

[0053] S5. Cooling and crystal removal: After growth is complete, the plasma gas path is turned off and heating is stopped in sequence. The crystal is then removed after cooling to room temperature at a rate of 0.2℃ / min.

[0054] Example 2: Diamond single crystal growth is performed using the top seed crystal solution method diamond single crystal growth apparatus of the present invention. The specific steps are the same as in Example 1, with the following differences: S1, preparation of flux: Weigh 50g of metal Ga and 20g of In as component A, 20g of metal Ni as component B, and 10g of metal Ge as component C. Mix them evenly and then put them into an isostatically pressed rhombic graphite crucible.

[0055] S2, Heating and Melting: Vacuuming to 10°C -3 After Pa, high-purity argon gas is introduced, and the temperature is increased to 1000℃ at 5℃ / min and held at that temperature for 4 hours.

[0056] S3, Seed crystal installation and inoculation: Silicon carbide (4H-SiC) single crystal is selected as the seed crystal and is lowered to contact the solution after being fixed.

[0057] S4, Plasma-assisted crystal growth: Seed crystal temperature controlled at 800℃, solution body temperature at 860℃, seed crystal rotation speed at 30 rpm, graphite crucible rotation speed at 15 rpm, growth time at 72 hours.

[0058] S5, Cooling and Crystal Removal: Remove the crystal after slow cooling.

[0059] Example 3: Diamond single crystal growth was performed using the top seed solution method diamond single crystal growth apparatus of the present invention. The specific steps were the same as in Example 1, with the following differences: S1, preparation of co-solvent: Weigh 70g of metallic Ga as component A, 15g of metallic Fe and 10g of metallic Ni as component B, and 5g of metallic Si as component C.

[0060] S2, heating and melting: same as in Example 1.

[0061] S3, Seed crystal installation and inoculation: Boron nitride (c-BN) single crystals are selected as seed crystals and, after being fixed, are lowered to contact the solution.

[0062] S4, Plasma-Assisted Crystal Growth: The plasma gas path assembly is activated, and a mixture of H2 and CH4 gas is introduced. The CH4 volume fraction is set to 3%, and the total plasma gas flow rate is 150 sccm. After ionization by the radio frequency plasma generator, the plasma gas flow is delivered above the seed crystal. The seed crystal temperature is set to 920℃, the bulk solution temperature to 980℃, the seed crystal rotation speed to 20 rpm (clockwise), the graphite crucible rotation speed to 10 rpm (counterclockwise), and the growth time to 36 hours.

[0063] S5, Cooling and Crystal Removal: Remove the crystal after slow cooling.

[0064] Specifically, the test results of the crystals obtained in Examples 1-3 are shown in Table 1 below.

[0065] Table 1 Crystal test results

[0066] Specifically, the standard characteristic peak of diamond is at 1332.2 cm⁻¹. -1 Example 1, which has no inclusions, basically meets this characteristic. However, the crystals obtained in Examples 2 and 3 have inclusions, resulting in greater internal stress and deviation.

[0067] In summary, this diamond single crystal growth method and apparatus based on the top-seeded solution method employs an ABC ternary flux system, utilizing a low-melting-point metal, a carbon-soluble metal, and sp... 3 The synergistic effect of hybrid framework agents achieves high carbon solubility and sp. 3The effective promotion of the hybrid diamond phase solves the problems of low carbon solubility and sp in traditional liquid-phase methods. 3 Technical challenges related to insufficient hybridization driving force.

[0068] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for growing diamond single crystals based on the top-seeded solution method, characterized in that, Includes the following steps: S1, Co-solvent Preparation: Prepare the co-solvent according to the ABC ternary system. Load the prepared co-solvent raw materials and carbon source into the growth container. Component A is any one or more of the low-melting-point metals Ga, In, Sn, and Cu; component B is any one or more of the carbon-soluble metals Fe, Co, Ni, and Mn; and component C is sp... 3 Any one or both of the hybrid framework agents Si and Ge; S2, Heating and Melting: Seal the growth container, evacuate it and fill it with protective gas, heat it to melt the cosolvent raw material, keep it at a constant temperature to fully dissolve the carbon source, and obtain a carbon-saturated solution; S3, Seed crystal installation and descent contact: Fix the seed crystal to the bottom of the seed crystal holder, and drive the seed crystal down to contact or immerse it in the carbon saturated solution; S4, Plasma-assisted crystal growth: Plasma gas flow is introduced into the growth container, the growth container is rotated, and diamond crystal growth is carried out on the surface of the seed crystal. During the growth process, the temperature of the seed crystal is maintained below 1200°C, and the temperature of the carbon saturated solution is higher than the temperature of the seed crystal. S5, Cooling and Crystal Extraction: After growth is complete, pull the seed crystal to remove it from the liquid surface, and slowly cool it down to obtain a diamond single crystal.

2. The diamond single crystal growth method based on the top seed crystal solution method as described in claim 1, characterized in that, In the cosolvent raw material, the mass percentage content of component A is 50% to 90%, the mass percentage content of component B is 5% to 40%, and the mass percentage content of component C is 0.1% to 15%.

3. The diamond single crystal growth method based on the top seed crystal solution method as described in claim 1, characterized in that, In step S2, the growth container is a graphite crucible, and the heating temperature is 800-1200℃, with a constant temperature time of 1-10h.

4. The diamond single crystal growth method based on the top seed crystal solution method as described in claim 1, characterized in that, In step S3, the seed crystal includes any one of silicon carbide single crystal, diamond single crystal, boron nitride single crystal, silicon-based diamond composite substrate, silicon-based boron nitride composite substrate, sapphire-based diamond composite substrate, and sapphire-based boron nitride composite substrate.

5. The diamond single crystal growth method based on the top seed crystal solution method as described in claim 1, characterized in that, In step S4, the plasma gas flow includes H2 and CH4, wherein CH4 accounts for 1 to 20% of the total volume percentage of the plasma gas flow. The total flow rate of the plasma gas is 50–1000 sccm.

6. The diamond single crystal growth method based on the top seed crystal solution method as described in claim 1, characterized in that, In step S4, the rotating growth container specifically includes: simultaneously starting the seed crystal rotation and the growth container rotation; The seed crystal rotates at a speed of 1 to 100 rpm, the growth container rotates at a speed of 1 to 100 rpm, and the seed crystal rotates in the opposite direction to the growth container.

7. A diamond single crystal growth apparatus based on the top seed solution method, characterized in that, include: A furnace body (1) is provided inside the furnace body (1), which contains a growth container (2) and a heating assembly (4), which is located around and / or on top of the growth container (2). The bottom of the growth container (2) is connected to the growth container lifting mechanism (51) and the growth container rotating mechanism (52) through the lower opening of the furnace body (1). The seed crystal lifting and rotating assembly includes a seed crystal rod (3) and a seed crystal holder (31) disposed at the bottom end of the seed crystal rod (3). The seed crystal rod (3) passes through the upper opening of the furnace body (1). A seed crystal is fixed at the bottom of the seed crystal holder (31), and a seed crystal lifting mechanism (61) and a seed crystal rotating mechanism (62) are connected to the top of the seed crystal rod (3). A temperature control system is used to control the temperature of the solution inside the growth container (2) and the temperature of the seed crystal; The plasma gas path assembly includes a gas supply source (71), a plasma generator (72), and a gas conduit (73), which extends from the furnace body (1) to the growth container (2) and is supplied with a plasma gas flow ionized by the plasma generator (72) from the gas supply source (71).

8. The diamond single crystal growth apparatus based on the top seed solution method as described in claim 7, characterized in that, The growth container (2) is a graphite crucible, which is made of isostatically pressed graphite material.

9. The diamond single crystal growth apparatus based on the top seed solution method as described in claim 7, characterized in that, The plasma generator (72) is a plasma torch or a radio frequency plasma device.

10. The diamond single crystal growth apparatus based on the top seed solution method as described in claim 7, characterized in that, The gas conduit (73) delivers the plasma gas flow to the surface of the solution near the seed crystal or immerses it in the solution.

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