A seed arrangement method for CVD polycrystalline diamond growth

Abstract

The present application relates to the technical field of crystal growth, in particular to a seed crystal arrangement device and method for CVD polycrystalline diamond growth. The device comprises a strong electric field coating device, which comprises an upper electrode plate and a lower electrode plate, the upper electrode plate being arranged directly above the lower electrode plate; a CVD polycrystalline diamond epitaxial substrate with adhesive is fixed to the lower surface of the upper electrode plate, and a non-metal plate is arranged on the upper surface of the lower electrode plate; a static high-voltage generator is connected to the lower electrode plate, and the upper electrode plate is grounded. The diamond powder and the CVD polycrystalline diamond epitaxial substrate are placed in the strong electric field coating device, the strength of the electrostatic field is matched according to the particle size, the voltage of the static high-voltage generator is 50,000-120,000 volts; the hydrogenated diamond powder forms a dipole moment under the strong electrostatic field, and is adsorbed onto the CVD polycrystalline diamond growth substrate from the lower part under the action of the Lorentz force, realizes the embedding of the conical bottom surface into the glue during the movement, the tip is outward, realizes the uniformity and consistency of the seed crystal arrangement; the device has a simple structure and a reasonable design.

Description

Technical Field

[0001] This invention relates to the field of crystal growth technology, and specifically to a seed crystal arrangement device and method for CVD polycrystalline diamond growth. Background Technology

[0002] Diamond wafer fabrication primarily employs methods such as high-temperature high-pressure (HPHT) and maximum-volume chemical vapor deposition (MPCVD). MPCVD can produce high-quality, colorless, and transparent polycrystalline diamond, applicable to fields such as optical windows and heat sinks. Currently, most CVD polycrystalline diamonds use silicon or silicon carbide as substrate materials. Surface nucleation is crucial for heteroepitaxial growth, and achieving high-density, uniform nucleation is paramount. Diamond, an atomic crystal with a tetrahedral spatial network structure formed by covalent bonds of carbon atoms, is difficult to form dipoles in an electric field and thus difficult to move under Lorentz forces.

[0003] Currently, most CVD growth of polycrystalline diamond employs spontaneous nucleation. However, due to the inherent temperature gradient and inhomogeneity in CVD temperature field control, especially in large-area diamond growth (inch-scale and above), uneven diamond nucleation density can occur, affecting the thickness uniformity of subsequent polycrystalline diamond films and making processing difficult. Application CN201810307217.5 discloses a seed planting method for CVD thick diamond films, which utilizes diamond micropowder to grind the surface of a molybdenum substrate, using the residue from the grinding process of micropowder of different particle sizes as seed crystals for diamond growth. This method suffers from issues related to seed crystal uniformity and consistency.

[0004] Current methods cannot achieve uniform, high-density, and consistent seed crystal arrangement for diamond growth on CVD polycrystalline diamond epitaxial substrates. This invention provides a seed crystal arrangement device and method for CVD polycrystalline diamond growth. Summary of the Invention

[0005] To address the aforementioned shortcomings, this invention provides a seed crystal arrangement device and method for CVD polycrystalline diamond growth.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a seed crystal arrangement device for CVD polycrystalline diamond growth, including a strong electric field coating device, the strong electric field coating device including an upper electrode plate and a lower electrode plate, the upper electrode plate being disposed directly above the lower electrode plate; a CVD polycrystalline diamond epitaxial substrate is fixed on the lower surface of the upper electrode plate, and a non-metallic plate is disposed on the upper surface of the lower electrode plate.

[0007] Connect the electrostatic high voltage generator to the lower electrode plate and ground the upper electrode plate.

[0008] A method for seed crystal arrangement in CVD polycrystalline diamond growth.

[0009] S1: Select cone-shaped or similar pointed irregular diamond micro powder, with a particle size of 0-50 micrometers;

[0010] S2: Place diamond micro powder into a CVD device for surface hydrogenation treatment;

[0011] S3: Processed diamond micro powder is evenly spread on a non-metallic plate using a resonance method, with a thickness of 10-300 micrometers;

[0012] S4: Spin coating treatment on the surface of CVD polycrystalline diamond epitaxial substrate;

[0013] S5: Place diamond micropowder and CVD polycrystalline diamond epitaxial substrate into a high-electric-field coating device, and perform static matching according to particle size.

[0014] Electric field strength, electrostatic high voltage generator voltage 50,000-120,000 volts; after hydrogenation, diamond micro powder forms a dipole moment under a strong electrostatic field, and is adsorbed from the bottom onto the CVD polycrystalline diamond growth substrate under the action of Lorentz force. By matching the electric field strength, the weight of diamond seed crystals can be further screened. During the movement, the conical bottom surface is embedded in the glue, and the tip faces outward, so as to achieve uniformity and consistency of seed crystal arrangement.

[0015] S6: Bake and cure the CVD polycrystalline diamond epitaxial substrate at a temperature of 0-350 degrees Celsius for 2-5 hours.

[0016] As an optimization, the adhesive used in the spin coating process can be an inorganic precursor such as silicon nitride, silicon oxide, or silicon carbide, and the thickness of the adhesive should be less than or equal to the particle size of the micro powder.

[0017] The beneficial effects of this invention are: This invention provides a seed crystal arrangement device and method for CVD polycrystalline diamond growth.

[0018] 1. Achieve a relatively uniform distribution of diamond single crystals with consistent orientation, thus ensuring the uniformity and consistency of the seed crystals;

[0019] 2. CVD diamond growth does not require promoting large-area spontaneous nucleation, and can directly and rapidly grow flat films; the structure is simple and the design is reasonable. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram showing the distribution of CVD diamond growth that does not utilize the present invention.

[0022] Figure 3 This is a schematic diagram illustrating the distribution of CVD diamond growth according to the present invention.

[0023] Among them, 1. upper electrode plate, 2. lower electrode plate, 3. CVD polycrystalline diamond epitaxial substrate, 4. non-metallic plate, 5. electrostatic high voltage generator, 6. silicon substrate, 601. first diamond single crystal, 602. first scratch, 7. silicon substrate, 701. second diamond single crystal, 702. second scratch. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] 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.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," and "right" are used interchangeably.

[0027] The terms "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] like Figure 1 The seed crystal arrangement device for CVD polycrystalline diamond growth shown includes a strong electric field coating device, which includes an upper electrode plate 1 and a lower electrode plate 2. The upper electrode plate 1 is disposed directly above the lower electrode plate 2. A CVD polycrystalline diamond epitaxial substrate 3 is fixed on the lower surface of the upper electrode plate 1, and a non-metallic plate 4 is disposed on the upper surface of the lower electrode plate 2.

[0029] A high-voltage electrostatic generator 5 is connected to the lower electrode plate 2, and the upper electrode plate 1 is grounded.

[0030] A method for seed crystal arrangement in CVD polycrystalline diamond growth.

[0031] S1: Select cone-shaped or similar pointed irregular diamond micro powder, with a particle size of 0-50 micrometers;

[0032] S2: Place diamond micro powder into a CVD device for surface hydrogenation treatment;

[0033] CVD equipment, also known as chemical vapor deposition equipment, is a type of thin film deposition equipment. It serves as the carrier for CVD applications and is the most widely used technology in industry for depositing various materials.

[0034] S3: Processed diamond micro powder is evenly spread on non-metallic plate 4 using a resonance method, with a thickness of 10-300 micrometers;

[0035] S4: Spin coating is applied to the surface of the CVD polycrystalline diamond epitaxial substrate 3;

[0036] The diamond micropowder is fixed to ensure uniform distribution of diamond single crystals, and the adhesive used for spin coating is an inorganic precursor that does not affect the growth of diamond single crystals.

[0037] S5: Diamond micro powder and CVD polycrystalline diamond epitaxial substrate 3 are placed in a strong electric field coating device. The electrostatic field strength is matched according to the particle size. The voltage of the electrostatic high voltage generator 5 is 50,000-120,000 volts. The hydrogenated diamond micro powder forms a dipole moment under the strong electrostatic field. Under the action of Lorentz force, it is adsorbed from the bottom onto the CVD polycrystalline diamond growth substrate. By matching the electric field strength, the weight of diamond seed crystals can be further screened. During the movement, the conical bottom surface is embedded in the glue, and the tip faces outward, so as to achieve uniformity and consistency of seed crystal arrangement.

[0038] The electrostatic high voltage generator 5 can adsorb diamond micro powder onto the CVD polycrystalline diamond epitaxial substrate 3, preventing the diamond micro powder from being dispersed due to the influence of the external environment.

[0039] S6: Bake and cure the CVD polycrystalline diamond epitaxial substrate 3 at a temperature of 0-350 degrees Celsius for 2-5 hours.

[0040] The curing temperature is 0-350 degrees Celsius and the time is 2-5 hours to completely cure the CVD polycrystalline diamond epitaxial substrate 3, avoiding the migration and uneven growth of CVD diamond.

[0041] Figure 2 The diagram shows the distribution of CVD diamond growth without utilizing this invention, and also shows the current state of CVD diamond growth.

[0042] The first silicon substrate 6 is roughened by diamond powder polishing. The first diamond single crystal 601 remains in the first scratch 602 with different orientations. In the early stage of CVD diamond growth, it is necessary to promote large-area spontaneous nucleation to achieve thin film flatness.

[0043] Figure 3 The diagram shows the distribution of CVD diamond growth using the present invention. The second silicon substrate 7 is roughened by diamond powder polishing. This technology uses electrostatic crystal implantation to achieve a relatively uniform distribution of the second diamond single crystal 701 with consistent orientation. The second diamond single crystal 701 will not be completely retained in the second scratch 702. The adhesive is an inorganic precursor such as silicon nitride and silicon oxide. After curing, it does not affect the growth of diamond. In CVD diamond growth, there is no need to promote large-area spontaneous nucleation, and the thin film can be grown directly and rapidly.

[0044] In this embodiment, the adhesive used in the spin coating process can be an inorganic precursor such as silicon nitride, silicon oxide, or silicon carbide, and the thickness of the adhesive is less than or equal to the particle size of the micro powder.

[0045] The adhesive used is an inorganic precursor, which does not affect the growth of diamond single crystals.

[0046] In this embodiment, electrostatic crystal implantation technology can be used to achieve a more uniform distribution of diamond single crystals with consistent orientation.

[0047] Working principle: This invention provides a seed crystal arrangement device and method for CVD polycrystalline diamond growth.

[0048] S1: Select cone-shaped or similar pointed irregular diamond micro powder, with a particle size of 0-50 micrometers;

[0049] S2: Place diamond micro powder into a CVD device for surface hydrogenation treatment;

[0050] S3: Processed diamond micro powder is evenly spread on non-metallic plate 4 using a resonance method, with a thickness of 10-300 micrometers;

[0051] S4: Spin coating is applied to the surface of the CVD polycrystalline diamond epitaxial substrate 3;

[0052] S5: Diamond micro powder and CVD polycrystalline diamond epitaxial substrate 3 are placed in a strong electric field coating device. The electrostatic field strength is matched according to the particle size. The voltage of the electrostatic high voltage generator 5 is 50,000-120,000 volts. The hydrogenated diamond micro powder forms a dipole moment under the strong electrostatic field. Under the action of Lorentz force, it is adsorbed from the bottom onto the CVD polycrystalline diamond growth substrate. By matching the electric field strength, the weight of diamond seed crystals can be further screened. During the movement, the conical bottom surface is embedded in the glue, and the tip faces outward, so as to achieve uniformity and consistency of seed crystal arrangement.

[0053] S6: Bake and cure the CVD polycrystalline diamond epitaxial substrate 3 at a temperature of 0-350 degrees Celsius for 2-5 hours.

[0054] This invention achieves a relatively uniform distribution of diamond single crystals with consistent orientation, ensuring the uniformity and consistency of the seed crystals.

[0055] CVD diamond growth does not require promoting large-area spontaneous nucleation, and allows for direct and rapid growth of flat films; the structure is simple and the design is reasonable.

[0056] The above-described specific embodiments are merely specific examples of the present invention. The patent protection scope of the present invention includes, but is not limited to, the product form and style of the above-described specific embodiments. Any appropriate changes or modifications made by a person skilled in the art that conform to the claims of the present invention should fall within the patent protection scope of the present invention.

Claims

1. A seed crystal arrangement method for CVD polycrystalline diamond growth, implemented using a CVD polycrystalline diamond growth seed crystal arrangement device, comprising a strong electric field coating device, the strong electric field coating device including an upper electrode plate and a lower electrode plate, the upper electrode plate being positioned directly above the lower electrode plate; a CVD polycrystalline diamond epitaxial substrate being fixed on the lower surface of the upper electrode plate, and a non-metallic plate being disposed on the upper surface of the lower electrode plate; an electrostatic high voltage generator being connected to the lower electrode plate, and the upper electrode plate being grounded, characterized in that: The method steps include: S1: Select cone-shaped or similar pointed irregular diamond micro powder, with a particle size of 0-50 micrometers; S2: Place diamond micro powder into a CVD device for surface hydrogenation treatment; S3: Processed diamond micro powder is evenly spread on a non-metallic plate using a resonance method, with a thickness of 10-300 micrometers; S4: Spin coating treatment on the surface of CVD polycrystalline diamond epitaxial substrate; S5: Place diamond micropowder and CVD polycrystalline diamond epitaxial substrate into a high-electric-field coating device, and perform static matching according to particle size. Electric field strength, electrostatic high voltage generator voltage 50,000-120,000 volts; hydrogenated diamond micropowder forms dipoles under a strong electrostatic field. The polar moment, under the action of Lorentz force, is adsorbed from the bottom onto the CVD polycrystalline diamond growth substrate. By matching the electric field strength, the weight of the diamond seed crystal can be further screened. During the movement, the conical bottom surface is embedded in the glue, and the tip faces outward, so as to achieve uniformity and consistency of seed crystal arrangement. S6: Bake and cure the CVD polycrystalline diamond epitaxial substrate at a temperature of 0-350 degrees Celsius for 2-5 hours.

2. The seed crystal arrangement method for CVD polycrystalline diamond growth according to claim 1, characterized in that: The adhesive used in the spin coating process can be made of inorganic precursors such as silicon nitride, silicon oxide, or silicon carbide, and the thickness of the adhesive should be less than or equal to the particle size of the micro powder.

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