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CN-121992497-A - Diamond crystal and growth deposition device and growth method thereof

CN121992497ACN 121992497 ACN121992497 ACN 121992497ACN-121992497-A

Abstract

The application discloses a diamond crystal and a growth deposition device and a growth method thereof, belonging to the technical field of vapor deposition. The diamond crystal satisfies the following conditions that a, the thickness difference between the edge area and the central area of the crystal is less than or equal to 10 mu m, b, the total dislocation defect density is less than 10 5 /cm 2 , c, the thickness of the crystal is 0.3-10mm, and d, the absolute value of stress is lower than 20MPa. By using the structure of actively adjusting the heights of the surface and the edge of the molybdenum support and combining a specific growth process, the growth method of keeping the heights of the surface of the crystal and the edge of the molybdenum support constant and inhibiting the edge effect is realized, and the diamond crystal with high quality and few cracks is obtained.

Inventors

  • YIN GUOXIAN
  • Pei Weibo
  • ZHU CAN
  • CHEN PENGLEI
  • ZHOU HUIQIN
  • DANG YIFAN
  • FAN ZHIPENG
  • GAO LIBO
  • Wang Muzhuang
  • LIU PENGFEI

Assignees

  • 上海天岳半导体材料有限公司

Dates

Publication Date
20260508
Application Date
20260410

Claims (10)

  1. 1. A diamond crystal, characterized in that the following conditions are satisfied: a. The thickness difference between the edge area and the central area of the crystal is less than or equal to 10 mu m; b. Total dislocation defect density <10 5 /cm 2 ; c. The thickness of the crystal is 0.3-10mm; d. The absolute value of the stress is lower than 20MPa.
  2. 2. The diamond crystal according to claim 1, wherein the crystal has a TTV of <10 μm on the upper surface and a TTV of <10 μm on the lower surface; The number of cracks in the crystal that are crack-free or greater than 10 μm in the crystal is 1.
  3. 3. A diamond growth deposition apparatus, comprising: the outer molybdenum support assembly is sequentially connected with an outer molybdenum support, an outer base and an outer bearing column from top to bottom, wherein the outer base is detachably connected with the outer bearing column, and an opening is formed in the center of the outer molybdenum support; The inner molybdenum support assembly is arranged at the central part of the outer molybdenum support assembly, and is sequentially connected with an inner molybdenum support, an inner base and an inner bearing column from top to bottom, the inner base is detachably connected with the inner bearing column, the inner molybdenum support is arranged in a central opening of the outer molybdenum support, the outer molybdenum support and the inner molybdenum support are arranged coaxially, and a gap exists between the inner molybdenum support and the outer molybdenum support; the driving system is connected with the inner bearing column and is used for driving the inner bearing column to lift and rotate; The outer bearing column and the inner bearing column are internally provided with spiral circulating water cooling channels.
  4. 4. A diamond growth deposition apparatus according to claim 3 wherein the diameter of the inner molybdenum support corresponds to the diameter of the seed crystal, and/or The distance between the inner molybdenum support and the outer molybdenum support is a, and the value range of a is 0.05-1.0mm.
  5. 5. A diamond growth deposition device according to claim 3 wherein the lifting stroke of the drive system is 0.1mm to 20mm and the speed at which the inner support post is driven to rotate is 0.1 to 20rpm.
  6. 6. A dynamic height compensated MPCVD diamond growth method using a diamond growth deposition apparatus according to any one of claims 3 to 5, comprising the steps of: (1) Pre-treating, namely placing seed crystals on an inner molybdenum support, vacuumizing a cavity, and carrying out in-situ etching cleaning on the surfaces of the seed crystals; (2) Under the atmosphere of hydrogen, sequentially introducing methane, oxygen, nitrogen and argon to enable seed crystals to grow to 0.3-10mm in thickness at the temperature of 800-1200 ℃ under the pressure of 5k-30 kPa; In the growing process, the inner molybdenum support is driven to rotate and descend through the driving system, so that the diamond growing surface is not higher than the upper surface of the outer molybdenum support; (3) And (3) annealing, namely closing methane after the growth is finished, keeping the temperature of the crystal at 800-1200 ℃, closing nitrogen, oxygen and argon, annealing the crystal in a hydrogen atmosphere at 800-1000 ℃ for 1-10h, and cooling to obtain the crystal.
  7. 7. A dynamic height compensated MPCVD diamond growth method according to claim 6, wherein the inner molybdenum support is rotated at a speed of 0.1-20rpm in step (2), and/or The descending speed of the inner molybdenum support is 0.1-100 mu m/h.
  8. 8. The dynamic height compensated MPCVD diamond growth method of claim 6, wherein the difference in height between the diamond growth surface and the upper surface of the outer molybdenum support in step (2) is d, and d ranges from 0mm to 2.0mm.
  9. 9. The dynamic height compensated MPCVD diamond growth method of claim 6, wherein the sequentially introducing methane, oxygen, nitrogen, and argon in step (2) comprises: s1, under the hydrogen atmosphere, introducing methane with the volume fraction of 3-5% for 1-2h; S2, reducing the volume fraction of methane to 1-2%, and introducing oxygen with the volume fraction of 0.1-2% for 5-10min; S3, introducing nitrogen with the volume fraction of 0.1-2% for 5-10min; And S4, finally introducing argon with the volume fraction of 0.1-2%.
  10. 10. The dynamic height compensated MPCVD diamond growth method of claim 6, wherein in step (2) a borane gas or a phosphine gas is also introduced.

Description

Diamond crystal and growth deposition device and growth method thereof Technical Field The application relates to a diamond crystal, a growth deposition device and a growth method thereof, and belongs to the technical field of vapor deposition. Background Microwave Plasma Chemical Vapor Deposition (MPCVD) has become the most favored diamond growth technology in scientific research and high-end industrial applications because of its pollution-free, high controllability, and ability to grow high-quality diverse diamond materials. In the diamond growth process, the molybdenum support is generally used as a diamond growth base due to the chemical stability, and is placed on a red copper base, and a water cooling system is arranged inside the red copper base and is used for heat dissipation. The quality of diamond growth is extremely dependent on the uniformity of the plasma. However, as the deposition process continues, the diamond crystal continues to thicken, creating the defect that ① plasma distorts the crystal height, bending the electric field lines toward the center, resulting in a fringe electric field strength significantly higher than the center, inducing uncontrolled impurity growth (parasitic growth). ② The thermal field fluctuates, after the crystal protrudes out of the tray, the heat dissipation environment at the side surface of the crystal is suddenly changed, so that the radial temperature difference is increased, and the crystal stress cracking is easily caused. ③ Thickness bottleneck-due to the change of the height changing the optimal growth process window, single growth thickness is severely limited, and large-size, high-quality and high-thickness crystals are difficult to realize. Disclosure of Invention The invention aims at the difficult problem and provides a diamond crystal, a growth deposition device and a growth method thereof, wherein the structure of actively adjusting the heights of the surface and the edge of the molybdenum support is used, and the growth method of keeping the heights of the surface of the crystal and the edge of the molybdenum support constant and inhibiting the edge effect is realized by combining a specific growth process, so that the diamond crystal with high quality and few cracks is obtained. According to a first aspect of the present application, there is provided a diamond crystal satisfying the following conditions: a. The thickness difference between the edge area and the central area of the crystal is less than or equal to 10 mu m; b. Total dislocation defect density <10 5/cm2; c. The thickness of the crystal is 0.3-10mm; d. The absolute value of the stress is lower than 20MPa. The edge area and the central area of the diamond crystal of the application both keep high-quality monocrystal structure, the thickness difference between the edge and the center is very small, the uncontrolled impurity crystal of the edge is very little, the crystallographic orientation is highly consistent, the impurity crystal area is prevented from being used as an impurity diffusion channel or a stress concentration point, and the performance consistency of the whole crystal is ensured. Specifically, the edge region is an outer region with a radius of 1/2 from the geometric center of the crystal. Specifically, the central region is an inner region with a radius of 0-1/2 from the geometric center of the crystal. Optionally, the crystal has a TTV of <10 μm on the upper surface and a TTV of <10 μm on the lower surface. Alternatively, there are no cracks in the crystal or the number of cracks in the crystal greater than 10 μm is 1. According to a second aspect of the present application, there is provided a diamond growth deposition apparatus comprising: the outer molybdenum support assembly is sequentially connected with an outer molybdenum support, an outer base and an outer bearing column from top to bottom, the outer base is detachably connected with the outer bearing column, and an opening is formed in the center of the outer molybdenum support; The inner molybdenum support assembly is arranged at the central part of the outer molybdenum support assembly, and is sequentially connected with an inner molybdenum support, an inner base and an inner bearing column from top to bottom, the inner base is detachably connected with the inner bearing column, the inner molybdenum support is arranged in a central opening of the outer molybdenum support, the outer molybdenum support and the inner molybdenum support are arranged coaxially, and a gap exists between the inner molybdenum support and the outer molybdenum support; the driving system is connected with the inner bearing column and is used for driving the inner bearing column to lift and rotate; The outer bearing column and the inner bearing column are internally provided with spiral circulating water cooling channels. The outer molybdenum support component and the inner molybdenum support component in the growth deposition dev