Device for growing diamond seed crystals

Abstract

The utility model relates to a device for growing diamond seed crystals, which comprises a microwave resonant cavity, and a growth table with a water cooling structure inside is arranged in the cavity. The growth base station is arranged on the growth table and is used for placing a diamond seed crystal to be grown, the growth table is provided with a concave opening part which is concavely arranged downwards, the microwave resonant cavity further comprises an adjusting mechanism which can at least change the local sectional area of the concave opening part, the adjusting mechanism comprises an adjusting part and a driving part, and the driving part is used for driving the adjusting part to rotate. In the state that the driving part drives the growth table and / or the adjusting part to move relative to the growth base table, the adjusting part can be used for shielding the notch part, so that the contact area between the growth table and the growth base table is reduced. According to the utility model, the notch part is arranged on the growth table, the opening and the shielding part are arranged on the adjusting plate, and the growth table rotates under the condition that the driving part provides power, so that the local sectional area of the notch part is changed, and the growth temperature required by seed crystals is adjusted.

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 the main method for diamond preparation. During the diamond growth process, the growth temperature becomes the key to high-quality growth. If the equipment cannot adjust the diamond growth temperature, the debugging time before startup will be very long.

[0003] For this reason, people have designed a device that is convenient for adjusting the growth temperature of diamonds. For example, an invention patent with patent number CN202310916192.X (publication number CN116926666A) discloses "A microwave reaction device that is convenient for adjusting the growth temperature". The device adjusts the distance between the growth base and the growth platform through a lifting mechanism. When the height of the growth base is higher and the distance from the growth platform is farther, the upper surface of the diamond seed crystal enters the high electric field area more, and the energy obtained from the plasma will be more, thereby achieving the adjustment of the growth temperature of the diamond seed crystal. At the same time, since the metal growth platform body is provided with water cooling, the growth platform basically maintains a constant temperature, and the top of the growth platform is the growth base. When the growth base rises relative to the metal growth platform, the distance between the two increases, the heat dissipation will become slower, and the same amount of energy enters the growth base, and the temperature will rise; on the contrary, when it falls, the heat dissipation becomes faster, and the same amount of energy enters the growth base, and the temperature will drop. By combining the water cooling mechanism with the lifting mechanism, the plasma energy and heat dissipation speed obtained by the diamond seed crystal on the growth base can be adjusted, thereby achieving precise control of the growth temperature of the diamond seed crystal.

[0004] However, the applicant has concluded through multiple simulation tests that the temperature adjustment method through the lifting mechanism has a small adjustable range of temperature, and only by maintaining a specific height can the energy obtained by the diamond seed crystal from the plasma in the microwave resonant cavity remain stable to promote its stable growth. However, as the thickness of the diamond seed crystal continues to increase during the growth process, its distance from the plasma light ball is actually reduced, which will cause the temperature of the diamond seed crystal to increase accordingly. If a lifting device is used to reduce the distance between the diamond seed crystal and the plasma light ball, as analyzed above, the adjustable range of the temperature of the diamond seed crystal is relatively small. For those skilled in the art, the most direct way is to directly reduce the power of the plasma light ball, but this method will also affect the growth of the diamond seed crystal. Therefore, it is necessary to find another temperature adjustment device. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a device capable of adjusting the growth temperature of diamond seed crystals in view of the above-mentioned existing technical status.

[0006] The technical solution adopted by the utility model to solve the above technical problems is: the device for growing diamond seed crystals includes:

[0007] Microwave resonant cavity;

[0008] A growth platform, disposed in the microwave resonant cavity, and provided with a water cooling structure; and

[0009] A growth base, which is arranged on the growth platform and is used to place the diamond seed crystal to be grown;

[0010] The feature is that: at least two downwardly recessed notches are provided on the growth platform, the microwave resonance cavity also includes an adjustment mechanism that can at least change the local cross-sectional area of ​​the notches, the adjustment mechanism includes an adjustment member and a driving part arranged on the growth platform, when the driving part drives the growth platform and / or the adjustment member to move relative to the growth base, the adjustment member can be used to cover the notches to reduce the contact area between the growth platform and the growth base.

[0011] In order to be able to adjust the partial cross-sectional area of ​​the notch, preferably, the driving part only drives the growth platform to rotate circumferentially relative to the growth base, and the adjusting member includes an adjusting plate, and the adjusting plate is provided with a shielding part corresponding to each notch, and the shielding part can at least partially shield the notch as the growth platform rotates circumferentially. According to the different circumferential rotation angles of the growth platform, the growth platform and the adjusting plate can present three states: the first state: the notch is completely shielded by the shielding part; the second state: the notch is partially overlapped with the opening (i.e., the notch is partially shielded by the shielding part); the third state: the notch is completely overlapped with the opening.

[0012] In order to adjust the local cross-sectional area of ​​the notch during the circumferential rotation of the growth platform, preferably, the adjustment plate is provided with at least two openings spaced apart along the circumferential direction, and the interval between the adjacent openings constitutes the shielding portion. When the opening rotates circumferentially above the notch by a certain angle, the shielding portion will cover the notch.

[0013] In order to achieve the transfer of cold energy and maintain the stability of the adjustment plate, preferably, the adjustment member also includes a peripheral wall extending downward along the periphery of the adjustment plate, and the peripheral wall is at least partially in contact with the outer peripheral wall of the growth platform. A water cooling mechanism is provided inside the growth platform, and the cooling water can transfer cold energy to the growth platform. The growth platform can transfer cold energy to the adjustment plate by heat conduction through contact with the adjustment plate, and the adjustment plate further transfers cold energy to the growth base placed above the adjustment plate; and the peripheral wall extending downward is connected to the connecting piece below the growth platform, which can also achieve the stability of the connection between the adjustment plate and the growth platform.

[0014] In order to provide power for the circumferential movement of the growth platform, preferably, the driving part includes a motor, the motor is arranged on the bracket, the power output end of the motor is connected to a transmission mechanism, and the transmission mechanism is connected to a connecting rod used to drive the growth platform to rotate circumferentially relative to the growth base. After the motor is powered on, it starts to run and provides power to the transmission mechanism, and the transmission mechanism drives the connecting rod and the growth platform connected to the connecting rod to move together.

[0015] In order to achieve power transmission, preferably, the transmission mechanism includes a first pulley driven by the motor, a synchronous belt meshing with the first pulley, and a second pulley meshed with the synchronous belt, the lower end of the connecting rod is connected to the second pulley, and the upper end of the connecting rod is connected to the growth platform. After the motor is powered on, it first drives the first pulley to start rotating, and the synchronous belt meshing with the first pulley starts to run synchronously under the drive of the first pulley, and the second pulley and the connecting rod connected to the second pulley rotate synchronously under the drive of the synchronous belt.

[0016] In order to fix the adjustment plate, preferably, the microwave resonant cavity is provided with a connecting piece below the growth platform, the peripheral wall of the adjustment plate is connected to the connecting piece, and a penetration portion for the connecting rod to penetrate is provided in the center of the connecting piece. The adjustment plate remains stationary, and the growth platform rotates relative to the adjustment plate, making the adjustment process more convenient.

[0017] In order to prevent the connecting rod from destroying the vacuum environment in the cavity, preferably, a vacuum tube is provided on the outer shell of the connecting rod, the connecting rod rotates in the vacuum tube, and the connecting rod and the vacuum tube extend from the bottom of the growth platform to below the second pulley.

[0018] In order to maintain the vacuum in the microwave resonance cavity, preferably, the microwave resonance cavity is provided with a sealing mechanism for maintaining the vacuum of the cavity, and the sealing mechanism includes a first sealing part and a second sealing part, the first sealing part is sealed and connected to the bottom of the microwave resonance cavity, the first sealing part is provided with a space for the connecting rod and the vacuum tube to pass through, and the second sealing part is sealed and connected to the bottom of the connecting rod and the vacuum tube. The first sealing part is used to close the gap between the vacuum tube and the connecting rod passing through the bottom of the microwave resonance cavity, and the second sealing part is used to close the open area formed by the vacuum tube and the bottom of the connecting rod.

[0019] Compared with the prior art, the advantages of the utility model are:

[0020] 1. A notch is provided on the growth table, and an opening and a shielding portion corresponding to the notch are provided on the adjustment plate. When the driving part provides power, the growth table rotates along the circumferential direction, thereby changing the local cross-sectional area of ​​the notch and adjusting the internal environment of the microwave resonance cavity to the growth temperature required by the seed crystal;

[0021] 2. By driving the growth table and / or the adjusting member to move relative to the growth base, the contact area between the growth table and the growth base can be changed. The operation is simple, and the temperature can be adjusted in a wide range. The appropriate growth temperature ensures the growth quality of the seed crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the growth platform and the adjustment plate in the embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the three-dimensional structure of the growth platform in the embodiment of the utility model;

[0024] Figure 3 It is a top view of the embodiment of the utility model in which the opening of the adjustment plate and the notch of the growth platform completely overlap;

[0025] Figure 4 It is a top view of the partially overlapping opening of the adjusting plate and the notch of the growing platform in the embodiment of the utility model;

[0026] Figure 5 It is a top view of the embodiment of the utility model in which the opening of the adjustment plate and the notch of the growth platform do not overlap;

[0027] Figure 6 It is a schematic diagram of the three-dimensional structure of the device of the embodiment of the utility model;

[0028] Figure 7 It is a cross-sectional view of the device according to the embodiment of the utility model.

[0029] In the figure: 1. microwave resonant cavity; 2. growth platform; 3. growth base; 4. adjustment mechanism; 41. adjustment plate; 42. driving part; 421. motor; 43. transmission mechanism; 44. synchronous belt; 45. first pulley; 46. second pulley; 5. opening; 6. notch; 7. shielding part; 8. sealing mechanism; 81. first sealing part; 82. second sealing part; 9. connecting rod; 10. bracket; 11. connecting piece; 111. penetration part. DETAILED DESCRIPTION

[0030] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0031] Embodiment 1:

[0032] like Figures 1 to 7 The device comprises a microwave resonant cavity 1 and a growth platform 2 arranged in the microwave resonant cavity 1, the growth platform 2 being provided with a water cooling structure; a growth base 3 arranged on the growth platform 2 and for placing the diamond seed crystal to be grown, at least two recessed portions 6 recessed downwardly are provided on the growth platform 2 (in order to ensure a better temperature adjustment effect, six recessed portions 6 are preferably provided in this embodiment), the microwave resonant cavity 1 also comprises an adjustment mechanism 4 capable of at least changing the partial cross-sectional area of ​​the recessed portions 6, the adjustment mechanism 4 comprising an adjustment member arranged on the growth platform 2 and a driving part 42, when the driving part 42 drives the growth platform 2 to move relative to the growth base 3, the adjustment member can be used to cover the recessed portions 6 to reduce the contact area between the growth platform 2 and the growth base 3.

[0033] This embodiment is described by taking the driving part 42 as only driving the growth platform 2 to rotate relative to the growth base 3 in the circumferential direction: wherein the growth platform 2 is cylindrical, and correspondingly, the adjusting member includes an adjusting plate 41, and the adjusting plate 41 is provided with a shielding part 7 corresponding to each notch 6, and the shielding part 7 can at least partially shield the notch 6 as the growth platform 2 rotates in the circumferential direction. wherein, according to different circumferential rotation angles of the growth platform 2, the growth platform 2 and the adjusting plate 41 can present three states: the first state: the notch 6 is completely shielded by the shielding part 7 (such as Figure 5 As shown), at this time, the contact area between the growth base 3 and the growth platform 2 is the smallest, and the cooling effect is the worst; the second state: the notch 6 partially overlaps with the opening 5, that is, the notch 6 is partially blocked by the blocking portion 7 (as shown Figure 4 As shown), at this time, the contact area between the growth platform 2 and the growth base 3 is larger than that in the first state, and the cooling efficiency of the seed crystal is improved, thereby reducing the growth temperature of the seed crystal; the third state: the notch 6 and the opening 5 are completely overlapped (as shown in FIG. Figure 3 As shown), at this time, the contact area between the growth platform 2 and the growth base 3 is the largest, the cooling efficiency of the seed crystal is the highest, and the growth temperature of the seed crystal can reach the maximum limit that the device can adjust.

[0034] like Figures 2 to 5 As shown, on the basis of ensuring that the local cross-sectional area of ​​the notch 6 can be changed, the number and size of the openings 5 ​​on the adjustment plate 41 and the notch 6 on the growth platform 2 can be arbitrarily designed. In this embodiment, the adjustment plate 41 is preferably provided with 6 openings 5 ​​spaced apart along the circumferential direction, and the intervals between adjacent openings 5 ​​constitute the shielding portion 7. The number of the openings 5 ​​and the notch 6 are matched and the size remains the same. The growth platform 2 can rotate counterclockwise or clockwise under the condition that the driving part 42 provides power. At this time, the adjustment plate 41 and the growth platform 2 can complete the switching of the three states.

[0035] like Figure 7 As shown, the adjusting member also includes a peripheral wall extending downward along the periphery of the adjusting plate 41, and the peripheral wall is at least partially in contact with the outer peripheral wall of the growth platform 2. A water cooling mechanism is provided inside the growth platform 2, and the cooling water can transfer the cold energy to the growth platform 2. The growth platform 2 can transfer the cold energy to the adjusting plate 41 by heat conduction through contact with the adjusting plate 41, and the adjusting plate 41 further transfers the cold energy to the growth base 3 placed above the adjusting plate 41. At this time, the growth temperature of the seed crystal on the growth base 3 can be reduced to the required growth temperature, and the peripheral wall extending downward is connected to the connecting member 11 below the growth platform 2, so as to ensure the stability of the connection between the adjusting plate 41 and the growth platform 2.

[0036] like Figure 6 and Figure 7 As shown, the driving part 42 of this embodiment includes a motor 421, which is arranged on the bracket 10. The power output end of the motor 421 is connected to a transmission mechanism 43, and the transmission mechanism 43 is connected to a connecting rod 9 used to drive the growth platform 2 to rotate circumferentially relative to the growth base 3. Among them, the motor 421 starts to operate after being energized and provides power to the transmission mechanism 43, and the transmission mechanism 43 drives the connecting rod 9 and the growth platform 2 connected to the connecting rod 9 to move together. The transmission mechanism 43 includes a first pulley 45 driven to rotate by the motor 421, a synchronous belt 44 meshed with the first pulley 45 for transmission, and a second pulley 46 meshed with the synchronous belt 44 for transmission. The lower end of the connecting rod 9 is connected to the second pulley 46, and the upper end of the connecting rod 9 is connected to the growth platform 2. Since the first pulley 45 and the second pulley 46 of the transmission mechanism are prior art, their specific structures are not repeated. After the motor 421 is powered on, it first drives the first pulley 45 to start rotating. Driven by the first pulley 45, the synchronous belt 44 meshing with the first pulley 45 starts to run synchronously. Driven by the synchronous belt 44, the second pulley 46 and the connecting rod 9 connected to the second pulley 46 rotate synchronously together.

[0037] like Figure 7As shown, the microwave resonant cavity 1 is provided with a connecting piece 11 below the growth platform 2, the peripheral wall of the adjustment plate 41 is connected to the connecting piece 11, and a through-hole 111 for the connecting rod 9 to pass through is provided in the center of the connecting piece 11. The adjustment plate 41 remains stationary, and the growth platform 2 rotates relative to the adjustment plate 41, making the adjustment process more convenient.

[0038] like Figure 6 and Figure 7 As shown, the connecting rod 9 is provided with a vacuum tube to prevent it from destroying the vacuum environment in the cavity. The connecting rod 9 rotates in the vacuum tube. The connecting rod 9 and the vacuum tube extend from the bottom of the growth platform 2 to the bottom of the second pulley 46. The microwave resonance cavity 1 is provided with a sealing mechanism 8 to maintain the vacuum degree of the cavity. The sealing mechanism 8 includes a first sealing portion 81 and a second sealing portion 82. The first sealing portion 81 is sealed and connected to the bottom of the microwave resonance cavity 1. The first sealing portion 81 is provided with a space for the connecting rod 9 and the vacuum tube to pass through. The second sealing portion 82 is sealed and connected to the bottom of the connecting rod 9 and the vacuum tube. The first sealing portion 81 is used to close the gap between the vacuum tube and the connecting rod 9 passing through the bottom of the cavity, and the second sealing portion 82 is used to close the open area formed by the vacuum tube and the bottom of the connecting rod 9, so that the microwave resonance cavity 1 is in a closed vacuum state as a whole.

[0039] Specific working process: Place the diamond seed crystal on the growth base 3. In the first state, the opening 5 on the adjustment plate 41 and the notch 6 on the growth platform 2 do not overlap at all. As the seed crystal continues to grow, the thickness of the seed crystal continues to increase, and its distance from the plasma photosphere gradually decreases, so that the growth temperature of the seed crystal continues to increase. At this time, it is necessary to turn on the power supply to start the motor 421. After the motor 421 drives the first pulley 45 to start rotating, the synchronous belt 44 meshing with the first pulley 45 and the second pulley 46 meshing with the synchronous belt 44 also start to rotate synchronously. The second pulley 46 drives the connecting rod 9 connected to it and the growth platform 2 fixedly connected to the connecting rod 9 to move synchronously. At this time, the notch 6 on the growth platform 2 gradually overlaps with the opening 5. The growth table 2 and the growth base 3 are connected, that is, the contact area between the growth table 2 and the growth base 3 gradually increases, and the growth table 2 and the growth base 3 are switched from the first state to the second state. At this time, the cooling rate of the seed crystal on the growth base 3 is accelerated, and the growth temperature of the seed crystal gradually decreases; when the growth thickness of the seed crystal reaches a certain value, the growth temperature in the second state cannot meet the most suitable growth temperature of the seed crystal. At this time, the driving part 42 needs to drive the growth table 2 to rotate synchronously again until the notch 6 on the growth table 2 is completely overlapped with the opening 5 on the adjustment plate 41, that is, the contact area between the growth table 2 and the growth base 3 is the largest. At this time, the growth table 2 and the growth base 3 are switched from the second state to the third state. At this time, the cooling rate of the seed crystal on the growth base 3 is the fastest, and the seed crystal can be adjusted to the most suitable growth temperature.

[0040] Embodiment 2:

[0041] The notch 6 of the growth table 2 of the device and the opening 5 on the adjustment plate 41 are arranged in radial direction and correspond one to one in the vertical direction. The motor 421 of the driving part 42 can provide power to the growth table 2, driving the growth table 2 to perform radial translation movement in the adjustment plate 41. At this time, the growth table 2 and the adjustment plate 41 can achieve the same three states as in Example 1, and the rest of the structure in the device is consistent with Example 1. The specific working process is as follows:

[0042] A diamond seed crystal is placed on the growth base 3. In the first state, the opening 5 on the adjustment plate 41 and the notch 6 on the growth platform 2 do not overlap at all. As the seed crystal continues to grow, the thickness of the seed crystal continues to increase, and its distance from the plasma photosphere gradually decreases, so that the growth temperature of the seed crystal continues to increase. At this time, it is necessary to turn on the power supply to start the motor 421. The motor 421 drives the transmission mechanism 43 to operate. Under the transmission of the transmission mechanism 43, the connecting rod 9 performs a translational motion in the vacuum tube, and the connecting rod 9 drives the growth platform 2 to perform a synchronous translational motion. At this time, the notch 6 on the growth platform 2 gradually overlaps with the opening 5, that is, the contact area between the growth platform 2 and the growth base 3 gradually increases, and the growth The growth platform 2 and the growth base 3 are switched from the first state to the second state, at which time the cooling rate of the seed crystal on the growth base 3 is accelerated, and the growth temperature of the seed crystal gradually decreases; when the growth thickness of the seed crystal reaches a certain value, the growth temperature in the second state cannot meet the most suitable growth temperature of the seed crystal. At this time, the driving part 42 needs to drive the growth platform 2 to perform synchronous translational movement again until the notch 6 on the growth platform 2 completely coincides with the opening 5 on the adjustment plate 41, that is, the contact area between the growth platform 2 and the growth base 3 reaches the maximum. At this time, the growth platform 2 and the growth base 3 are switched from the second state to the third state, the cooling rate of the seed crystal on the growth base 3 is the fastest, and the seed crystal can be adjusted to the most suitable growth temperature.

Claims

1. A device for growing diamond seed crystals, comprising: Microwave resonant cavity (1); A growth platform (2) is arranged in the microwave resonance cavity (1) and is provided with a water cooling structure; and A growth base (3), arranged on the growth platform (2) and for placing the diamond seed crystal to be grown; Features: The growth platform (2) is provided with at least two recessed portions (6) which are recessed downwards. The microwave resonance cavity (1) further comprises an adjustment mechanism (4) which can at least change a partial cross-sectional area of ​​the recessed portion (6). The adjustment mechanism (4) comprises an adjustment member arranged on the growth platform (2) and a driving portion (42). When the driving portion (42) drives the growth platform (2) and / or the adjustment member to move relative to the growth base (3), the adjustment member can cover the recessed portion (6) to reduce the contact area between the growth platform (2) and the growth base (3).

2. The device according to claim 1, characterized in that: The driving part (42) only drives the growth platform (2) to rotate circumferentially relative to the growth base (3); the adjusting member comprises an adjusting plate (41); the adjusting plate (41) is provided with a shielding part (7) corresponding to each of the notches (6); and the shielding part (7) can at least partially shield the notch (6) as the growth platform (2) rotates circumferentially.

3. The device according to claim 2, characterized in that: The adjustment plate (41) is provided with at least two openings (5) spaced apart in the circumferential direction, and the interval between adjacent openings (5) constitutes the shielding portion (7).

4. The device according to claim 3, characterized in that: The adjusting member further comprises a peripheral wall extending downwardly along the peripheral edge of the adjusting plate (41), wherein the peripheral wall is at least partially in contact with the outer peripheral wall of the growing platform (2).

5. The device according to any one of claims 2 to 4, characterized in that: The driving part (42) comprises a motor (421), the motor (421) is arranged on a bracket (10), a power output end of the motor (421) is connected to a transmission mechanism (43), and the transmission mechanism (43) is connected to a connecting rod (9) for driving the growth platform (2) to rotate circumferentially relative to the growth base (3).

6. The device according to claim 5, characterized in that: The transmission mechanism (43) includes a first pulley (45) driven to rotate by the motor (421), a synchronous belt (44) meshed with the first pulley (45) for transmission, and a second pulley (46) meshed with the synchronous belt (44) for transmission. The lower end of the connecting rod (9) is connected to the second pulley (46), and the upper end of the connecting rod (9) is connected to the growth platform (2).

7. The device according to claim 6, characterized in that: The microwave resonant cavity (1) is provided with a connecting piece (11) below the growth platform (2); the peripheral wall of the adjustment plate (41) is connected to the connecting piece (11); and a penetration portion (111) for the connecting rod (9) to penetrate is provided in the center of the connecting piece (11).

8. The device according to claim 7, characterized in that: The connecting rod (9) is provided with a vacuum tube on its outer shell to prevent it from destroying the vacuum environment in the microwave resonance cavity (1); the connecting rod (9) rotates in the vacuum tube; the connecting rod (9) and the vacuum tube extend from the bottom of the growth platform (2) to below the second pulley (46).

9. The device according to claim 8, characterized in that: The microwave resonance cavity (1) is provided with a sealing mechanism (8) for maintaining the vacuum degree of the cavity, the sealing mechanism (8) comprising a first sealing portion (81) and a second sealing portion (82), the first sealing portion (81) being sealedly connected to the bottom of the microwave resonance cavity (1), the first sealing portion (81) being provided with a space for the connecting rod (9) and the vacuum tube to pass through, and the second sealing portion (82) being sealedly connected to the connecting rod (9) and the bottom of the vacuum tube.

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