Device for growing diamond seed crystals

Abstract

The device for growing the diamond seed crystal comprises a microwave resonant cavity, a growing table and a growing base table, and is characterized by further comprising an adjusting plate, an adjusting plate, a plurality of adjusting plates and a plurality of adjusting plates, and the adjusting plates are arranged in the microwave resonant cavity; the adjusting mechanism is arranged outside the microwave resonant cavity and comprises a driving part and an adjusting part, and at least the upper section of the adjusting part extends into the microwave resonant cavity and acts on the adjusting plate. Under the state that the driving part drives the adjusting part to drive the adjusting plate to move and / or incline relative to the growth table, the condition is changed; the molecular state spherical plasma generated by the microwave generation unit can be always positioned right above the growth base table; the diamond seed crystals on the growth base station can be always covered by the plasma balls, so that the heat distribution in the growth process of the diamond seed crystals is stabilized, and the quality and consistency of diamond growth are improved.

Description

Technical Field

[0001] The utility model relates to the field of crystal growth equipment, in particular to a device for growing diamond seed crystals. Background Art

[0002] Microwave plasma chemical vapor deposition (MPCVD) is a leading technology for preparing diamond materials. During the diamond growth process, controlling the growth temperature is a key factor in obtaining high-quality diamonds. For example, in the prior art, the Chinese utility model patent application number CN202310916192.X (publication number CN116926666A) discloses a microwave reaction device for conveniently adjusting the growth temperature. The device's growth base is connected to a lifting mechanism that can control the depth of the growth base into the plasma and adjust the distance between the growth base and the growth base body with a cooling mechanism. Although this solves the problem of obtaining plasma energy and regulating the heat dissipation rate for the diamond seed on the growth base, in order to ensure that the diamond seed receives uniform heat distribution throughout the growth process, there is another key factor: the plasma light ball must completely cover the growth base, that is, the plasma light ball must always be directly above the growth base. If the equipment cannot ensure that the plasma light ball completely covers the growth base, the seed may suffer from uneven heating, which will lead to a series of growth defects such as uneven texture, cracks, and conical bumps. These defects not only reduce the overall product qualification rate, but may also affect its ultimate practical performance. Therefore, controlling the uniform heat distribution during the growth of diamond seeds is crucial to improving the quality and consistency of diamond growth. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device for growing diamond seed crystals on a growth base, in which a plasma light ball can completely cover the diamond seed crystals on the growth base, in response to the above-mentioned existing technical status.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows: the device for growing diamond seed crystals includes:

[0005] microwave resonant cavity;

[0006] A growth platform is provided in the microwave resonant cavity, a pipeline is provided below the growth platform, and a circulating cooling medium is passed through the pipeline for water cooling; and

[0007] A growth base, disposed on the growth platform and for placing the diamond seed crystal to be grown;

[0008] It is characterized in that: it also includes:

[0009] an adjusting plate, disposed in the microwave resonant cavity, comprising a plate body, a first gap being left between the periphery of the plate body and the peripheral wall of the microwave resonant cavity, a central hole being provided in the center of the plate body for the pipe to pass through, and a second gap being left between the plate body and the peripheral wall;

[0010] The adjustment mechanism is arranged outside the microwave resonant cavity, and includes a driving part and an adjustment part at least the upper section of which extends into the microwave resonant cavity and acts on the adjustment plate. With the help of the above-mentioned first gap and second gap, when the driving part drives the adjustment part to drive the adjustment plate to move and / or tilt relative to the growth platform, the molecular spherical plasma generated by the microwave generating unit can always be located directly above the growth base.

[0011] To limit the movement distance and / or tilt angle of the adjustment plate relative to the growth platform, the pipe is preferably provided with a first stopper. The first stopper includes an upper limit flange perpendicular to the axis of the pipe, a lower limit flange parallel to the upper limit flange, and a connecting ring wall connecting the upper and lower limit flanges. The connecting ring wall is provided for the adjustment plate to fit within, and the second gap is formed between the adjustment plate and the connecting ring wall. The upper limit flange limits the upper limit position of the adjustment plate, while the lower limit flange limits the lower limit position of the adjustment plate.

[0012] The adjustment portion can be configured to adjust the adjustment plate using a variety of structures. For simplicity, the adjustment portion preferably includes at least three adjustment rods axially parallel to the axis of the pipe, with the rods spaced equidistantly around the circumference of the plate. Each adjustment rod can be adjusted individually, or multiple rods can be adjusted simultaneously. Adjusting a single adjustment rod individually tilts the adjustment plate relative to the growth platform, while adjusting all adjustment rods simultaneously allows the adjustment plate to move up and down relative to the growth platform.

[0013] In order to quantitatively move and / or tilt the growth stage, preferably, the outer surface of the adjustment rod has scales.

[0014] In order to allow the upper section of the adjustment portion to extend into the microwave resonant cavity, the microwave resonant cavity preferably has an entry hole for the adjustment rod to extend into and an extension hole for the adjustment rod to extend out. A passage for the adjustment rod to pass through is formed between the entry hole and the extension hole, and the passage is also axially parallel to the axis of the pipe. The adjustment rod extends from the entry hole into the passage, passes through the passage, and then extends from the extension hole. Driven by the driving portion, the adjustment rod can move up and down within the passage, thereby acting on the adjustment plate to cause it to move and / or rise and fall.

[0015] To ensure a vacuum environment within the microwave resonant cavity, the lower end of the passage preferably extends radially to form a receiving space between the passage and the adjusting rod, and a seal is provided within the receiving space. The seal prevents air from entering the microwave resonant cavity through the passage, thereby ensuring the cavity's sealing and maintaining a vacuum state during use.

[0016] To retain the seal, the microwave resonant cavity is preferably provided with a second retaining member. The second retaining member at least partially protrudes upward, extends into the accommodation space, and abuts against the seal. This second retaining member holds the seal within the accommodation space, preventing displacement or even loss of the seal during use of the device. This further ensures the sealing of the microwave resonant cavity and maintains a vacuum environment within the cavity during use.

[0017] Furthermore, the second limiting member has a through-hole for the adjusting rod to pass through, and the through-hole is connected to the channel, so that the adjusting rod can pass through the through-hole and the channel and then extend into the microwave resonant cavity.

[0018] Furthermore, the driving part is a manual structure or an automatic structure controlled by a control unit.

[0019] When the driving part is a manual structure, from the perspective of structural simplicity, it is preferred that the driving part is a manual structure, including a nut threadedly connected to the adjustment rod, and correspondingly, the lower section of each adjustment rod is provided with a thread adapted to the nut. When in use, the nut is rotated to drive the adjustment rod up and down.

[0020] Compared with the prior art, the advantages of the present invention are: an adjustment plate is provided in the microwave resonant cavity, and an adjustment mechanism is provided to move and / or tilt the adjustment plate relative to the growth platform, thereby changing the size of the microwave resonant cavity. At the same time, the electric field and other related factors in the device are tuned together, so that the molecular spherical plasma generated by the microwave generating unit can always be located directly above the growth base, so that the diamond seed crystal on the growth base can always be covered by the plasma ball, thereby stabilizing the heat distribution during the growth process of the diamond seed crystal and improving the quality and consistency of diamond growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a cross-sectional view of the device in Example 1 of the present utility model;

[0022] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0023] Figure 3 Exploded view of the adjustment mechanism in the embodiment of the utility model

[0024] Figure 4This is a top view of the adjustment plate in Example 1 of the present utility model;

[0025] Figure 5 Schematic diagram of the plasma ball formation process in Example 1 of the present utility model;

[0026] Figure 6 for Figure 4 Enlarged view of point B in the middle;

[0027] Figure 7 This is a schematic diagram of the structure of the plasma ball offset in an embodiment of the present utility model;

[0028] Figure 8 This is a schematic diagram of the structure of the plasma ball position adjustment in an embodiment of the present utility model. DETAILED DESCRIPTION

[0029] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0030] Example 1

[0031] like Figure 1-6 The figure shows the best embodiment of the present invention. The device for growing diamond seed crystals in this embodiment includes a microwave resonant cavity 1, a growth platform 2 disposed within the microwave resonant cavity 1, a growth base 3 disposed on the growth platform 2 and for placing the diamond seed crystals to be grown, an adjustment plate 4 disposed within the microwave resonant cavity 1, and an adjustment mechanism 5. A pipe 21 is disposed below the growth platform 2, through which a circulating cooling medium is passed for water cooling. The adjustment plate 4 includes a plate body, a first gap 41 being formed between the periphery of the plate body and the peripheral wall of the microwave resonant cavity 1, a central hole 42 for the pipe 21 to pass through being disposed in the center of the plate body, and a second gap 43 being formed between the two.

[0032] like Figure 1-2 As shown, the adjustment mechanism 5 is arranged outside the microwave resonant cavity 1, and includes a driving portion 51 and an adjustment portion whose upper section at least extends into the microwave resonant cavity 1 and acts on the adjustment plate 4. With the help of the first gap 41 and the second gap 43, the driving portion 51 drives the adjustment portion to drive the adjustment plate 4 to move and / or tilt relative to the growth platform 2, thereby changing: the molecular spherical plasma generated by the microwave generating unit can always be located directly above the growth base 3. In order to limit the distance the adjustment plate 4 moves relative to the growth platform 2 and / or the tilt angle, a first limiter 22 is provided on the pipe 21. The structure of the first limiter 22 can be seen in FIG. Figure 6, including an upper limit convex edge 221 perpendicular to the axis of the pipe 21, a lower limit convex edge 222 arranged parallel to the upper limit convex edge 221, and a connecting ring wall 223 connecting the upper limit convex edge 221 and the lower limit convex edge 222. The connecting ring wall 223 is for the adjustment plate 4 to be mounted, and the above-mentioned second gap 43 is formed between the adjustment plate 4 and the connecting ring wall 223.

[0033] Specifically, in this embodiment, the adjustment portion includes three adjustment rods 52 arranged axially parallel to the axis of the pipe 21, and each adjustment rod 52 is distributed at equal intervals along the circumference of the plate (see Figure 4 ), and the outer surface of the adjustment rod 52 has a scale. The drive portion 51 is a manual structure, including a nut threadedly connected to the adjustment rod 52. Correspondingly, the lower section of each adjustment rod 52 is provided with a thread adapted to the nut. By manually rotating the nut, the adjustment rod can be driven up and down. Each adjustment rod 52 can be adjusted individually, or multiple adjustment rods 52 can be adjusted simultaneously. When adjusting a single adjustment rod 52, the adjustment plate 4 can be tilted relative to the growth platform 2. The larger the adjustment scale, the greater the tilt angle. When adjusting three adjustment rods 52 simultaneously, the adjustment plate 4 can be moved up and down relative to the growth platform 2. The larger the adjustment scale, the greater the distance of the up and down movement.

[0034] In addition, if Figure 2-3 As shown, the microwave resonant cavity 1 has an entry hole 11 for the adjustment rod 52 to enter and an exit hole 12 for the adjustment rod 52 to extend. A channel 13 is formed between the entry hole 11 and the exit hole 12, through which the adjustment rod 52 passes. This channel 13 is also axially parallel to the axis of the pipe 21. To ensure a vacuum environment within the microwave resonant cavity 1, the lower end of the channel 13 extends radially to form a receiving space 14 between the channel 13 and the adjustment rod 52. A seal 6 is provided within the receiving space 14. This seal 6 forms an interference fit with the adjustment rod 52, thereby preventing air from entering the microwave resonant cavity 1 through the channel 13. This ensures the cavity is sealed and maintains a vacuum state during use. The microwave resonant cavity 1 also has a second stopper 15. The second stopper 15 at least partially protrudes upward and extends into the receiving space 14, contacting the seal 6 to retain the seal 6 within the receiving space 14, preventing the seal 6 from shifting or even falling during use, further ensuring the sealing of the microwave resonant cavity 1. In order to enable the adjusting rod 52 to extend into the channel 13, the second limiting member 15 has a through hole 16 for the adjusting rod 52 to pass through. The through hole 16 is connected to the channel 13. The upper section of the adjusting rod 52 passes through the through hole 16, extends from the insertion hole 11 into the channel 13, and then extends from the extension port. Driven by the driving part 51, it can move up and down in the channel 13, thereby acting on the adjusting plate 4 to move and / or lift it.

[0035] In summary, when the present device is used to grow diamond, microwaves are fed from the microwave inlet, converted through the coaxial waveguide and introduced into the microwave resonant cavity 1, reflected by the microwave resonant cavity 1 and focused above the growth base 3, resonating with the introduced mixed gas, which is then excited by the microwaves to form a plasma ball 7 (see Figure 5 ), and form a diamond chemical deposition environment under a specific vacuum environment. According to the appendix of the Chinese utility model patent No. CN201910354079.0 Figure 1 The plasma ball 7 of the microwave resonant cavity 1 needs to be formed directly above the growth platform 2. However, the position of the plasma ball 7 may be offset due to factors such as temperature, air pressure, gas flow rate, and microwave power. Figure 7 In the device of this embodiment, when the plasma ball 7 deviates, the nut can be manually rotated to move the adjustment rod 52 up and down in the channel 13, thereby acting on the adjustment plate 4 to move and lift it relative to the growth table 2. When one adjustment rod 52 is adjusted upward, the growth table 2 at the corresponding position of the adjustment rod 52 moves upward, causing the adjustment plate 4 to tilt. At this time, the shape of the microwave resonance cavity 1 changes accordingly, changing the angle of microwave reflection on the cavity, thereby causing the position where the plasma ball 7 is formed to move in the tilt direction of the adjustment plate 4, so that the position of the plasma ball 7 is always directly above the growth table 2, so that the diamond seed crystal on the growth base 3 is covered by the plasma ball 7. Figure 8 The three circumferentially equidistantly spaced adjustment rods 52 cooperate with each other to tilt the adjustment plate 4 in any direction, thereby allowing the plasma ball 7 to move in any direction as needed.

[0036] After simulation, the relationship between the adjustment distance of the adjustment rod 52 and the movement of the plasma ball 7 is shown in the following table:

[0037]

[0038] The table above indicates that the greater the tilt angle of adjustment plate 4, the greater the distance plasma ball 7 moves. This result confirms the quantitative adjustment effect of adjustment plate 4 on the formation position of plasma ball 7. By adjusting the formation position of plasma ball 7, plasma ball 7 can always be positioned directly above growth platform 2, thereby ensuring that the diamond seed crystal on growth base 3 is covered by plasma ball 7.

[0039] Example 2

[0040] The structure of the device of this embodiment is basically the same as that of Example 1, with the only difference being that the driving mode is an automatic structure. The device of this embodiment also includes a control unit for controlling the overall action of the device, which can control the temperature, air pressure, gas flow rate, and microwave power required for diamond growth. The control unit and the adjustment of related conditions can refer to the control mode disclosed in the Chinese utility model application with patent application number 202010818424.4. The specific structure will not be repeated here. In addition, the focus of this application is that the control unit is electrically connected to the driving part 51 and is configured to: adjust the adjustment rod 52 according to the offset of the plasma ball 7, thereby adjusting the inclination of the adjustment plate 4, so that the plasma ball 7 is always directly above the growth table 2. Taking into account the above-mentioned influencing factors, integrating the adjustment plate 4 into the automatic control mode of the control unit can be used as a new adjustment method.

Claims

1. A device for growing diamond seed crystals, comprising: Microwave resonant cavity (1); A growth platform (2) is arranged in the microwave resonant cavity (1), a pipe (21) is provided below the growth platform (2), and a circulating cooling medium is passed through the pipe (21) for water cooling; and A growth base (3) is arranged on the growth platform (2) and is used to place the diamond seed crystal to be grown; Its characteristics are: Also included are: an adjusting plate (4) disposed in the microwave resonant cavity (1) and comprising a plate body, a first gap (41) being left between the periphery of the plate body and the peripheral wall of the microwave resonant cavity (1), a central hole (42) for the pipe (21) to pass through being provided at the center of the plate body, and a second gap (43) being left between the two; An adjusting mechanism (5) is arranged outside the microwave resonant cavity (1), and comprises a driving portion (51) and an adjusting portion at least the upper portion of which extends into the microwave resonant cavity (1) and acts on the adjusting plate (4). By means of the first gap (41) and the second gap (43), when the driving portion (51) drives the adjusting portion to drive the adjusting plate (4) to move and / or tilt relative to the growth platform (2), the spherical plasma in the molecular state generated by the microwave generating unit can always be located directly above the growth base (3).

2. The device for growing diamond seed crystals according to claim 1, wherein: The pipe (21) is provided with a first limiting member (22), the first limiting member (22) comprising an upper limiting convex edge (221) perpendicular to the axis of the pipe (21), a lower limiting convex edge (222) arranged parallel to the upper limiting convex edge (221), and a connecting ring wall (223) connecting the upper limiting convex edge (221) and the lower limiting convex edge (222), the connecting ring wall (223) being provided for the adjusting plate (4) to be sleeved, and the second gap (43) being formed between the adjusting plate (4) and the connecting ring wall (223).

3. The device for growing diamond seed crystals according to claim 1 or 2, characterized in that: The adjustment portion comprises at least three adjustment rods (52) arranged axially parallel to the axis of the pipe (21), and the adjustment rods (52) are distributed at equal intervals along the circumference of the plate body.

4. The device for growing diamond seed crystals according to claim 3, characterized in that: The outer surface of the adjusting rod (52) is provided with scales.

5. The device for growing diamond seed crystals according to claim 3, wherein: The microwave resonant cavity (1) is provided with an insertion hole (11) for the adjusting rod (52) to be inserted into and an extension hole (12) for the adjusting rod (52) to be extended out. A channel (13) for the adjusting rod (52) to pass through is formed between the insertion hole (11) and the extension hole (12). The channel (13) is also arranged axially parallel to the axis of the pipe (21).

6. The device for growing diamond seed crystals according to claim 5, characterized in that: The lower end of the channel (13) extends radially and forms an accommodating space (14) between the lower end and the adjusting rod (52), and a sealing member (6) is provided in the accommodating space (14).

7. The device for growing diamond seed crystals according to claim 6, characterized in that: The microwave resonance cavity (1) is provided with a second limiting member (15), wherein the second limiting member (15) at least partially protrudes upwards and extends into the accommodating space (14) and contacts the sealing member (6).

8. The device for growing diamond seed crystals according to claim 7, characterized in that: The second position-limiting member (15) has a through-hole (16) for the adjusting rod (52) to pass through, and the through-hole (16) is connected to the channel (13).

9. The device for growing diamond seed crystals according to any one of claims 4 to 7, characterized in that: The driving part (51) is a manual structure or an automatic structure controlled by a control unit.

10. The device for growing diamond seed crystals according to claim 9, characterized in that: The driving part (51) is a manual structure, comprising a nut threadedly connected to the adjusting rod (52), and correspondingly, the lower section of each adjusting rod (52) is provided with a thread adapted to the nut.

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