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CN-120844191-B - Device and method for growing large-size diamond

CN120844191BCN 120844191 BCN120844191 BCN 120844191BCN-120844191-B

Abstract

The invention provides a device and a method for growing large-size diamond, and relates to the field of diamond growth. The device for growing large-size diamond comprises a sample support, wherein at least two sample support grooves are formed in the sample support, limiting strips are arranged between adjacent sample support grooves and are not communicated with each other, chamfering angles are arranged on one edge or two opposite edges of the top of a seed crystal, the chamfering angles of the seed crystal positioned in the adjacent sample support grooves are arranged oppositely, the height of the seed crystal is larger than that of the limiting strips, and the depth of the chamfering angles is larger than the difference between the height of the seed crystal and the height of the limiting strips. The invention solves the problem that the joint of the seed crystals is suspended in the growth process, stabilizes the temperature of the joint area, reduces the defect generation of the joint area, and improves the joint success rate between the seed crystals.

Inventors

  • QIAN YULI

Assignees

  • 上海晶世创新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20250714

Claims (9)

  1. 1. The device for growing the large-size diamond is characterized by comprising a sample support (1), wherein at least two sample support grooves (11) are formed in the sample support (1), limiting strips (2) are arranged between adjacent sample support grooves (11) and are not communicated with each other, seed crystals are arranged in the sample support grooves (11), and chamfers are arranged on one edge or two opposite edges of the top of each seed crystal; The chamfers of the seed crystals in the adjacent sample support grooves (11) are arranged oppositely, and the height of the limiting strip (2) is between the top of the seed crystals and the lowest position of the chamfers.
  2. 2. The device for growing large-size diamond according to claim 1, wherein the width of the limit bar (2) is 0.2-1.0 mm, the limit bar (2) is prismatic in shape, and the top surface is an arc surface.
  3. 3. The device for growing large-sized diamond according to claim 1, wherein the limit bar (2) is triangular prism in shape, the top edge is provided with a round angle, and the round angle is 0.1-0.5 mm.
  4. 4. The device for growing large-sized diamond according to claim 3, wherein the two inner angles of the limit strips (2) at the bottom are the same and are 30-45 ̊.
  5. 5. The apparatus for growing large-sized diamond according to claim 1, wherein the difference between the height of the seed crystal (12) and the height of the limit bar (2) is 0.2-1.0 mm.
  6. 6. The apparatus for growing large-sized diamond according to claim 1, wherein the chamfer angle is 15-75 ̊ mm and the chamfer depth is 0.01-0.6 mm.
  7. 7. The apparatus for growing large-sized diamond according to claim 1, wherein the plurality of side walls of the seed crystal (12) are respectively bonded to the inner wall of the sample supporting groove (11) and the side walls of the limit strips (2).
  8. 8. A method for growing large-size diamond, which adopts the device for growing large-size diamond according to any one of claims 1 to 7, and comprises the following steps: Step 1) putting a plurality of independent seed crystals (12) into different sample groove grooves (11), then carrying out primary growth on the seed crystals (12), wherein the growth surface of the seed crystals (12) gradually passes through a limit strip (2) in the primary growth process, so that adjacent seed crystals (12) are spliced, gaps between the adjacent seed crystals (12) are eliminated, and a temperature transmission channel between the adjacent seed crystals (12) is established; And 2) carrying out secondary growth on the seed crystal (12) after the primary growth in the step 1), wherein in the secondary growth process, the growth surface of the seed crystal (12) in the primary growth is used as the bottom surface to be directly contacted with the sample holder (1).
  9. 9. A method of growing large-size diamond according to claim 8, comprising the following technical features: And step 2) further comprises the step of trimming the seed crystal (12) which is subjected to primary growth in the step 1) in a laser treatment mode, and carrying out secondary growth on the seed crystal (12) after trimming, wherein in the secondary growth process, the growth surface of the seed crystal (12) in the primary growth is used as the bottom surface to be directly contacted with the sample holder (1).

Description

Device and method for growing large-size diamond Technical Field The invention relates to the field of diamond growth, in particular to a device and a method for growing large-size diamond. Background Mosaic splice growth technology of large-size single crystal diamond has received attention in recent years as an important solution to break through the crystal size limitation. The technology realizes epitaxial fusion of adjacent seed crystals in a high-temperature high-pressure (HTHP) or Chemical Vapor Deposition (CVD) environment by precisely regulating and controlling various geometric arrangements and crystal orientations. The prior art route is mainly used for trying to realize atomic level matching of seed crystal splicing interfaces by optimizing the step height difference (usually controlled within +/-0.5 mu m) and the interface inclination angle (accurate to the order of 0.1 ̊) of the seed crystals and matching with submicron-level gap control (< 1 mu m). However, experimental data shows that even if the splice joint 4 between seed crystals is reduced to 0.3 μm, there is a significant distortion of the temperature field in the region of the splice joint 4, and the splice joint 4 can be referred to in fig. 8. The core mechanism of the thermal field distortion phenomenon present in the splice seam stems from the substantial difference in the interfacial heat transfer pattern of the splice seam 4. In a typical CVD/HTHP process, the seed crystal body dissipates heat efficiently by solid state heat conduction, and only a gaseous medium (e.g., H 2/Ar gas mixture) is present in the gaps between the seed crystals, which has a sudden drop in thermal conductivity, creating a significant thermal resistance barrier, i.e., the problem of suspending the seed crystals during growth. According to finite element simulation, a vertical temperature gradient of 150-200 ℃ can be formed at two sides of a gap between seed crystals with the temperature of about 0.3 μm under the condition of 900 ℃ of the substrate, and the heat flow density of the vertical temperature gradient is reduced by 2-3 orders of magnitude compared with that of a seed crystal body. The asymmetric thermal transport eventually causes a multiple interface mismatch effect, namely firstly, shearing stress is generated by thermal expansion difference between a high-temperature region (the center of a splicing seam 4) and a low-temperature region (a seed crystal body), the stress is in a range of 2-4 MPa and is enough to cause dislocation slip (critical slitting stress is about 1 MPa) through X-ray diffraction (XRD) strain analysis, secondly, the diffusion coefficient of a hydrocarbon group in a gas medium increases exponentially with temperature (D=D 0 exp (-Ea/kT) and Ea is about 2.1 eV), the supersaturation degree (delta C/C 0) of a carbon source at the splicing seam 4 is 3-5 times higher than that of the surface of the seed crystal 12, abnormal lateral epitaxial growth is induced, and more importantly, the hysteresis of gas thermal conduction (response time tau is about D2/alpha_gas, alpha_gas is gas thermal diffusivity) causes the temperature oscillation amplitude to reach +/-25 ℃ in a dynamic growth process, and the periodic variation of the interface is about 34% is generated by the step flow speed of the interface through in-situ observation of synchronous radiation, and the periodic defect array is formed at the interval of about 300. In view of the foregoing, there is a need for an apparatus that can solve the thermal field distortion of diamond seeds during growth. Disclosure of Invention In order to solve the problems, the invention provides a device for growing large-size diamond, which can solve the problem that seed crystals are suspended at a splicing joint in the growth process. The device for growing large-size diamond comprises a sample support, wherein at least two sample support grooves are formed in the sample support, limiting strips are arranged between adjacent sample support grooves and are not communicated with each other, the sample support grooves are used for placing external seed crystals, chamfer angles are formed in one edge or two opposite edges of the top of each seed crystal, chamfer angles of the seed crystals positioned in the adjacent sample support grooves are arranged oppositely, and the height of each limiting strip is between the top of each seed crystal and the lowest position of each chamfer angle. In a possible implementation manner, the width of the limit strip is 0.2-1.0 mm. In a possible implementation manner, the shape of the limit bar is a prism and the surface of the top is an arc surface. In a possible implementation manner, the shape of the limit bar is a triangular prism, the edge at the top is provided with a round angle, and the round angle is 0.1-0.5 mm. In a possible implementation manner, the two inner angles of the limit strips at the bottom are the same, and are both 30-45 ̊. In a possible imple