A growth station assembly for single crystal diamond synthesis

Abstract

The utility model provides a kind of for single crystal diamond synthesis's growth platform assembly, belong to the technical field of diamond prepared by chemical vapor deposition method.Growth platform assembly includes fixed platform component and lifting platform component, fixed platform component includes fixed platform and fixed rod, lifting platform component includes lifting platform and lifting rod, recess for the sinking of lifting platform is equipped on fixed platform, the position for the passage of lifting rod on fixed platform is equipped with guide sleeve, lifting rod is equipped with the guide cooperation part matched with the inner wall of guide sleeve, the cooperation clearance between lifting platform and recess satisfies that lifting platform component can smoothly move up and down.The utility model no longer utilizes lifting platform and recess to guide, there can be greater gap between the two, utilize the guide cooperation part on lifting rod and guide sleeve cooperation, can guarantee guide precision, while the temperature of lifting rod is lower, the outer peripheral area is smaller, the contact area of guide cooperation part and guide sleeve is small, can reduce moving resistance, avoid appearing jam.

Description

Technical Field

[0001] This utility model relates to a growth stage assembly for the synthesis of single-crystal diamond, belonging to the field of diamond preparation technology by chemical vapor deposition. Background Technology

[0002] Microwave plasma chemical vapor deposition (MPCVD) is the preferred method for preparing high-quality single-crystal diamond. Because the growth of high-quality single-crystal diamond requires a special growth environment, higher demands are placed on the functionality of MPCVD equipment. The temperature required for single-crystal diamond growth has a significant impact on the quality and efficiency of the synthesis; therefore, ensuring the temperature and uniformity during the synthesis of single-crystal diamond wafers is crucial for the efficient preparation of high-quality single-crystal diamond.

[0003] The growth of single-crystal diamond is carried out on a growth stage assembly, which includes a water-cooled stage and a growth substrate. Traditionally, the growth substrate is a solid molybdenum stage. This type of growth substrate alters its overall temperature and heat dissipation distribution by adjusting its combination (integral, double-layer, triple-layer, or multi-layer configurations using high thermal conductivity copper as the bottom layer) and structural form (purely solid, or with a centrally located annular groove), thereby ensuring the temperature and uniformity of the single-crystal diamond wafer. This method introduces limitations to temperature control. Each temperature test requires a shutdown to adjust the growth substrate combination until a suitable combination is achieved. Furthermore, under high power and high pressure conditions (where the growth temperature of single-crystal diamond is far higher than the required process temperature), relying solely on the growth substrate to transfer heat to the water-cooled stage is insufficient for temperature control.

[0004] In response, Chinese invention patent application CN113957522A discloses an MPCVD device for diamond single crystal growth. The MPCVD device includes an integrated structure of a coaxial antenna and a water-cooled stage. This integrated structure consists of an antenna assembly (i.e., a fixed stage assembly) and a lifting water-cooling component (i.e., a lifting stage assembly) coaxially fitted together. The antenna assembly has an antenna rod (i.e., a fixed rod) connected to the lower part of the fixed water-cooled stage (i.e., the fixed stage). The lifting water-cooling component has a connecting rod (i.e., a lifting rod) connected to the lower part of the liftable water-cooled stage (i.e., the lifting stage). A substrate is placed on the lifting stage. The lifting rod passes through the fixed stage and the fixed rod, and its lower end is used to connect to a lifting drive device to adjust the diamond growth temperature by changing the vertical height of the lifting stage.

[0005] The aforementioned lifting platform requires guidance during its vertical movement. This is typically achieved by using the sidewall of the groove on the fixed platform. However, diamonds generate very high temperatures during growth, and the platform surface directly contacts the substrate (i.e., the molybdenum stage). This causes the lifting platform to expand due to heat, resulting in close contact with the sidewall of the groove. Furthermore, the large contact area between the lifting platform and the sidewall of the groove increases the resistance to movement of the lifting platform, causing it to jam and affecting the adjustment effect. Utility Model Content

[0006] The purpose of this invention is to provide a growth stage assembly for the synthesis of single-crystal diamond, so as to solve the problem that the lifting stage in the prior art becomes stuck due to increased resistance to movement after thermal expansion.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A growth stage assembly for single-crystal diamond synthesis includes a fixed stage assembly and a lifting stage assembly. The fixed stage assembly includes a fixed stage and a fixed rod connected to the fixed stage and extending downward. The lifting stage assembly includes a lifting stage and a lifting rod connected to the lifting stage and extending downward. The fixed stage has a groove for the lifting stage to sink into. The lifting rod passes through the fixed stage and the fixed rod, and its lower end is used to connect to a lifting drive device. A guide sleeve is installed on the fixed stage at the position where the lifting rod passes through. The lifting rod has a guide mating part that cooperates with the inner wall of the guide sleeve to guide the vertical movement of the lifting stage assembly. The mating clearance between the lifting stage and the groove is sufficient to allow the lifting stage assembly to move smoothly up and down.

[0008] The beneficial effects of the above technical solution are as follows: This utility model is an improved invention, adding a guide sleeve and further limiting the fitting clearance between the lifting platform and the groove. Specifically, a guide sleeve is installed on the fixed platform at the position where the lifting rod passes through. The lifting rod has a guide fitting part that cooperates with the inner wall of the guide sleeve to guide the up and down movement of the lifting platform assembly. At the same time, the fitting clearance between the lifting platform and the groove is sufficient to allow the lifting platform assembly to move smoothly up and down. That is to say, the lifting platform and the groove are no longer used for guidance, and there can be a larger gap between them, so that even if the lifting platform expands due to heat, there will be no jamming. After the improvement, the guide fitting part on the lifting rod cooperates with the guide sleeve, which can ensure the guiding accuracy. At the same time, there is a certain distance between the lifting rod and the platform surface of the lifting platform. Compared with the lifting platform, the temperature of the lifting rod will be slightly lower, and the outer circumferential area of ​​the lifting rod is smaller, resulting in a smaller contact area between the guide fitting part and the guide sleeve. Therefore, the moving resistance can be greatly reduced, and jamming can be avoided.

[0009] Furthermore, the guide fitting part is an annular protrusion protruding on the outer circumferential surface of the lifting rod.

[0010] Furthermore, the longitudinal section of the annular protrusion is arc-shaped.

[0011] Furthermore, the guide sleeve has a flange, which is fixed to the mounting plate by screws.

[0012] Furthermore, the guide sleeve is a graphite copper sleeve.

[0013] Furthermore, the lifting platform is a solid platform, and the lifting rod includes a solid rod segment connected to the lifting platform and a hollow rod segment connected below the solid rod segment, with the guide fitting part disposed on the solid rod segment.

[0014] Furthermore, the fixing platform includes a copper disk and a copper ring separately disposed on the top surface of the copper disk. The guide sleeve is installed on the copper disk, and the groove is formed by the inner cavity of the copper ring and the top surface of the copper disk.

[0015] Furthermore, the copper ring includes an inner copper ring and an outer copper ring arranged in a nested manner. The inner cavity of the inner copper ring and the top surface of the copper disk together form the groove. The upper and lower thickness of the inner copper ring is greater than the upper and lower thickness of the outer copper ring.

[0016] Furthermore, a copper ring is placed on the top surface of the copper plate for easy removal and placement.

[0017] Furthermore, a sealing device is installed at the lower end of the fixed rod and the outside of the lifting rod, and the upper and lower ends of the sealing device are respectively sealed and fixedly connected to the outer circumferential surfaces of the fixed rod and the lifting rod. Attached Figure Description

[0018] Figure 1 This is a front sectional view of an embodiment of the growth stage assembly for single-crystal diamond synthesis according to the present invention. Figure 2 This is a front sectional view of the fixed stage in the embodiment of the growth stage assembly for single-crystal diamond synthesis of this utility model. Figure 3 This is a front sectional view of the lifting platform in the embodiment of the growth stage assembly for single-crystal diamond synthesis of this utility model. Figure 4 This is a partial cross-sectional view of the lifting platform in the embodiment of the growth stage assembly for single-crystal diamond synthesis of this utility model. Figure 5 This is a schematic diagram of the sealing device in the embodiment of the growth stage assembly for single-crystal diamond synthesis of this utility model.

[0019] In the diagram: 1. Copper disk; 2. Inner copper ring; 3. Outer copper ring; 4. Water distribution plate; 5. Antenna disk; 6. Fixing screw; 7. Sealing groove; 8. Copper disk connector; 9. Water distribution plate connector; 10. Antenna mast; 11. Lifting platform; 12. Solid mast section; 12-1. Annular protrusion; 12-2. Mast joint; 13. Hollow mast section; 14. Guide sleeve; 15. Fixing screw; 16. Molybdenum plate stage; 17. Molybdenum ring; 18. Single crystal diamond; 19. Plasma sphere; 20. Water collector; 20-1. Water collector body; 2 0-2, Plug; 20-3, First sealing ring; 20-4, Sealing ring; 20-5, Second sealing ring; 20-6, Nut; 20-7, Lower connector; 20-8, Upper connector; 21, Fixed frame; 22, Sealing device; 22-1, Telescopic cover; 22-2, Upper collar; 22-3, Upper nut cover; 22-4, Upper sealing ring; 22-5, Lower collar; 22-6, Lower nut cover; 22-7, Lower sealing ring; 23, Double clamping coupling; 24, Lifting motor; 25, Third sealing ring. Detailed Implementation

[0020] To address the technical problems existing in the prior art, the basic concept of this utility model is to add a guide sleeve to the fixed platform, change the guiding and mating position of the fixed platform assembly and the lifting platform assembly, and guide the up and down movement of the lifting platform assembly by the guide mating part on the lifting rod cooperating with the inner wall of the guide sleeve. The lifting platform and the groove are no longer used for guidance, and there can be a larger mating gap between the two. The temperature rise of the guide mating part is smaller and the outer peripheral area is smaller, which can reduce the moving resistance and avoid jamming.

[0021] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0022] The implementation method of the growth stage assembly (hereinafter referred to as the growth stage assembly) for single-crystal diamond synthesis in this utility model is as follows: like Figure 1 As shown, the growth stage assembly includes a fixed stage assembly and a lifting stage assembly. The fixed stage assembly includes a fixed stage and a fixed rod connected to the fixed stage and extending downward. The lifting stage assembly includes a lifting stage 11 and a lifting rod connected to the lifting stage 11 and extending downward. The lifting rod passes through the fixed stage and the fixed rod, and its lower end is used to connect to a lifting drive device. A molybdenum wafer stage 16 is placed on the platform of the lifting stage 11. A molybdenum ring 17 is provided around the molybdenum wafer stage 16. A plasma sphere 19 is formed above the molybdenum wafer stage 16 for growing single-crystal diamond 18 on the molybdenum wafer stage 16.

[0023] Combination Figure 1 and Figure 2As shown, the fixed stage assembly in this embodiment has a water-cooling function, and therefore can also be called a water-cooled stage assembly. Specifically, the fixed stage in this embodiment includes a copper disk 1 and a copper ring separately disposed on the top surface of the copper disk 1. The inner cavity of the copper ring and the top surface of the copper disk 1 together form a groove into which the lower ends of the lifting stage 11 and the molybdenum sheet stage 16 are inserted to adjust the growth height of the single crystal diamond 18. At the same time, the copper disk 1 and the copper ring have good thermal conductivity. By adjusting the vertical height of the lifting stage 11, the cooling effect of the water-cooled stage assembly on the lifting stage 11 can be changed. The cooling effect is best when the lifting stage 11 is in contact with the copper disk 1.

[0024] Furthermore, the copper ring includes an inner copper ring 2 and an outer copper ring 3 arranged in a nested configuration. The inner cavity of the inner copper ring 2 and the top surface of the copper disk 1 together form the aforementioned groove. The vertical thickness of the inner copper ring 2 is greater than that of the outer copper ring 3. Compared to a single copper ring with equal thickness, this reduces copper consumption and saves costs. At the same time, the weight of the two separate inner copper ring 2 and outer copper ring 3 is not excessive, making them easy for operators to handle.

[0025] Furthermore, in this embodiment, both the inner copper ring 2 and the outer copper ring 3 are placed directly on the top surface of the copper disk 1 for easy removal and placement. After diamond growth is complete, by removing the inner copper ring 2 and the outer copper ring 3 and raising the lifting platform 11, impurities grown on the top surface of the copper disk 1 can be easily cleaned. After cleaning, the inner copper ring 2 and the outer copper ring 3 can be simply put back, making the operation quite convenient.

[0026] In other embodiments, the inner copper ring 2 and the outer copper ring 3 can be fixed to the copper disk 1 with screws. In other embodiments, the inner copper ring 2 and the outer copper ring 3 can be machined into a single copper ring, meaning there is only one copper ring. In this case, the single copper ring has a stepped structure. Alternatively, the single copper ring can be machined into a copper ring of uniform thickness, eliminating the stepped structure. In other embodiments, the copper ring can be integrally connected to the copper disk 1, meaning the copper ring and the copper disk are formed from a single piece of copper material. In this case, the copper ring cannot be removed.

[0027] The mounting platform also includes a water distribution plate 4 and an antenna disk 5. The bottom of the copper disk 1 has a downward-facing stepped groove. The water distribution plate 4 is located within the stepped groove, and the antenna disk 5 is fixed to the stepped groove by fixing screws 6, thus pressing the water distribution plate 4 between the copper disk 1 and the antenna disk 5. A third sealing ring 25 is provided between the antenna disk 5 and the copper disk 1 to achieve a seal and prevent coolant leakage. Furthermore, the outermost ring of the stepped groove and the antenna disk 5 form a sealing groove 7, which is used to mate with the cavity of the MPCVD equipment to form a vacuum seal.

[0028] The water distribution plate 4 and the bottom of the stepped groove form an upper cooling water cavity, and the water distribution plate 4 and the antenna disk 5 form a lower cooling water cavity. A connecting hole connecting the upper cooling water cavity and the lower cooling water cavity is provided on the water distribution plate 4 near the outer circle.

[0029] The copper plate 1 has a central hole that runs vertically through it. A downward-extending copper plate connecting pipe 8 is connected to the central hole of the copper plate. The central hole of the copper plate and the copper plate connecting pipe 8 are for the lifting rod to pass through.

[0030] A central hole is provided at the center of the water distribution plate 4. A downwardly extending water distribution plate connector 9 is connected to the central hole of the water distribution plate. The water distribution plate connector 9 is nested outside the copper plate connector 8, and an annular space is formed between the two. This annular space is connected to the upper cooling water cavity.

[0031] The antenna disk 5 has a central hole at its center, and an antenna rod 10 (i.e., antenna disk connector) extending downwards is connected to the central hole. The antenna rod 10 is nested outside the water distribution plate connector 9, and an annular space is formed between the two. This annular space is connected to the lower cooling water cavity.

[0032] The antenna mast 10, the water distribution plate connector 9, and the copper plate connector 8 constitute the aforementioned fixing rod, and a water collector 20 is connected to the lower part of the fixing rod. Specifically, as follows... Figure 2 As shown, the water collector 20 includes a water collector body 20-1 and a plug 20-2 that is sealed and fixedly connected to the lower end of the water collector body 20-1. The lower end of the antenna rod 10 is provided with an external thread. The lower end of the antenna rod 10 extends into the water collector body 20-1 and is threadedly connected to the water collector body 20-1. A second sealing ring 20-5 is provided between the lower end face of the antenna rod 10 and the water collector body 20-1. After the two are tightened and fixed, the second sealing ring 20-5 is squeezed to achieve a seal between the two, thus preventing coolant leakage.

[0033] Meanwhile, a nut 20-6 is threaded onto the lower end of the antenna mast 10. After the antenna mast 10 is tightened and fixed to the water collector body 20-1, the nut 20-6 is tightened and pressed against the upper end face of the water collector body 20-1 to prevent loosening between the antenna mast 10 and the water collector body 20-1 and to ensure the water leakage prevention effect.

[0034] The lower end of the water distribution plate connector 9 extends through the antenna rod 10 and inserts into the water collector body 20-1. Preferably, the outer circumferential surface of the water distribution plate connector 9 and the inner wall of the water collector body 20-1 are in close contact to prevent communication between the annulus between the antenna rod 10 and the water distribution plate connector 9 and the annulus between the copper disk connector 8 and the water distribution plate connector 9. Alternatively, a sealing ring can be provided between the outer circumferential surface of the water distribution plate connector 9 and the inner wall of the water collector body 20-1 to ensure airtightness and prevent communication between the two annulus spaces.

[0035] The plug 20-2 is threaded to the lower end of the water collector body 20-1. A first sealing ring 20-3 is provided between the plug 20-2 and the lower end face of the water collector body 20-1. At the same time, a sealing ring 20-4 is provided between the upper end of the plug 20-2 and the outer circumferential surface of the copper disc connector 8. After the plug 20-2 is tightened, both the first sealing ring 20-3 and the sealing ring 20-4 are deformed under pressure. The sealing ring 20-4 hugs the copper disc connector 8, achieving a seal between the plug 20-2 and the copper disc connector 8, and at the same time achieving a double seal between the plug 20-2 and the water collector body 20-1 to prevent coolant leakage.

[0036] Furthermore, the water collector body 20-1 is equipped with a lower connector 20-7 that provides an annular connection between the copper plate connecting pipe 8 and the water distribution plate connecting pipe 9, and an upper connector 20-8 that provides an annular connection between the water distribution plate connecting pipe 9 and the antenna mast 10. The lower connector 20-7 and the upper connector 20-8 are arranged facing the same side of the water collector 20 to facilitate connection with an external cooling system. In other embodiments, the orientation of the two connectors may differ depending on the specific circumstances.

[0037] In this embodiment, the lower connector 20-7 serves as the water inlet connector, and the upper connector 20-8 serves as the water outlet connector. The coolant enters the annular space between the copper disc connector 8 and the water distribution plate connector 9 through the lower connector 20-7, then flows upwards to the upper cooling water chamber within the fixed platform. The coolant disperses from the center outwards and flows into the lower cooling water chamber along the connecting holes on the water distribution plate 4. The coolant then converges from the surrounding areas to the center and flows downwards along the annular space between the water distribution plate connector 9 and the antenna mast 10 to the water collector body 20-1. Finally, it flows through the upper connector 20-8 to the external cooling system, thus cooling the fixed platform and indirectly cooling the lifting platform 11. In other embodiments, the lower connector 20-7 can also serve as the water outlet connector, in which case the upper connector 20-8 serves as the water inlet connector.

[0038] like Figure 1 and Figure 2 As shown, a guide sleeve 14 is installed on the copper plate 1 at the position through which the lifting rod passes. The lifting rod has a guide engagement part that mates with the inner wall of the guide sleeve 14 to guide the up-and-down movement of the lifting platform assembly. There is sufficient clearance between the lifting platform 11 and the aforementioned groove to allow for smooth up-and-down movement of the lifting platform assembly. That is, the lifting platform 11 and the groove are no longer used for guidance; a larger clearance allows for them, preventing jamming even if the lifting platform 11 expands due to heat. Simultaneously, the engagement of the guide engagement part on the lifting rod with the guide sleeve 14 ensures guiding accuracy. Furthermore, the distance between the lifting rod and the platform surface of the lifting platform 11 results in a slightly lower temperature for the lifting rod compared to the lifting platform 11, and the smaller outer circumferential area of ​​the lifting rod reduces the contact area between the guide engagement part and the guide sleeve 14, thus significantly reducing movement resistance and preventing jamming.

[0039] Specifically, the guide sleeve 14 has a flange, which is fixed to the copper disk 1 by fixing screws 15, so that the guide sleeve 14 can be replaced after wear. By replacing the guide sleeve 14 in a timely manner, the increased clearance between the lifting rod and the guide sleeve 14 after wear can be avoided, which would cause radial swaying of the lifting platform 11. Furthermore, the guide sleeve 14 is fixed at the position of the center hole of the copper disk, and the guide sleeve 14 does not protrude from the top surface of the copper disk 1, preferably being flush with the top surface of the copper disk 1. In other embodiments, the guide sleeve 14 can also be threaded onto the copper disk 1 to achieve detachability. Of course, in other embodiments, the guide sleeve 14 can also be glued and fixed to the copper disk 1.

[0040] Furthermore, in this embodiment, the guide sleeve 14 is a graphite copper sleeve, which has low friction and can achieve a better guiding effect. In other embodiments, the guide sleeve can also be a copper sleeve or a graphite sleeve.

[0041] like Figure 3 and Figure 4 As shown, the lifting platform 11 in this embodiment is a solid platform. The lifting rod includes a solid rod segment 12 connected to the lifting platform 11 and a hollow rod segment 13 connected below the solid rod segment 12. The guide fitting part is provided on the solid rod segment 12. The length of the solid rod segment 12 is much smaller than the length of the hollow rod segment 13. By combining solid and hollow parts, the heat conduction effect of the lifting platform 11 can be guaranteed, while the setting of the guide fitting part can be facilitated. It can also reduce the overall weight of the lifting rod, which is beneficial for the lifting drive device to control the lifting platform assembly to move up and down.

[0042] Specifically, the aforementioned guide fitting part is an annular protrusion 12-1 protruding from the outer circumference of the solid rod segment 12, and the longitudinal section of the annular protrusion 12-1 is arc-shaped. In this way, the solid rod segment 12 and the guide sleeve 14 are in line contact, with a relatively small contact area. Even if the solid rod segment 12 expands due to heat, it will still be in line contact with the guide sleeve 14, which can avoid surface contact and frictional resistance caused by mutual movement after thermal expansion. In addition, the vertical movement accuracy of the lifting platform assembly cannot be absolutely guaranteed. After the arc-shaped annular protrusion 12-1 is used to fit with the guide sleeve 14, even if the lifting rod has a slight sway due to error, it will not jam with the guide sleeve 14, ensuring the smooth movement of the lifting rod.

[0043] In other embodiments, the longitudinal section of the annular protrusion 12-1 can also be rectangular or trapezoidal. In this case, the annular protrusion 12-1 and the guide sleeve 14 are in surface-to-surface contact. Although there is a certain contact area, it is very small compared to the prior art, so the moving resistance is very small. Of course, in other embodiments, the annular protrusion 12-1 can be omitted, and the outer peripheral surface of the solid rod segment 12 can be used to cooperate with the guide sleeve 14 directly. Although the contact area is increased compared to the annular protrusion, it is still small compared to the prior art. Moreover, the position of the solid rod segment 12 is farther from the top surface of the lifting platform 11, and the expansion deformation is relatively small. Therefore, the technical problem proposed by this utility model can still be solved.

[0044] In this embodiment, the hollow rod segment 13 is a stainless steel tube. In order to facilitate the fixed connection between the hollow rod segment 13 and the solid rod segment 12, a necked rod joint 12-2 is provided at the end of the solid rod segment 12. The hollow rod segment 13 is sleeved on the outside of the rod joint 12-2 and welded to the rod joint 12-2 for fixation. Of course, in other embodiments, the two can also be connected by threads.

[0045] In addition, such as Figure 1 As shown, the growth stage assembly also includes a fixed frame 21, which is fixed relative to the cavity of the MPCVD equipment. The water collector 20 is fixed on the top of the fixed frame 21, and the lifting drive device is a lifting motor 24 fixed on the bottom of the fixed frame 21. That is, the fixed frame 21 provides support and fixation for the water collector 20 and the lifting motor 24.

[0046] During assembly, the lifting rod of the lifting platform assembly passes through the copper disc connector 8 from top to bottom. The lower end of the copper disc connector 8 extends into the fixed frame 21. The lower end of the hollow rod section 13 extends out of the copper disc connector 8 and also into the fixed frame 21. The lower end of the hollow rod section 13 is fixedly connected to the double-clamping coupling 23. The double clamping ensures the reliability of the connection with the lifting rod. The top output end of the lifting motor 24 is a screw. The bottom surface of the double-clamping coupling 23 has a threaded hole. The screw and the threaded hole are connected to enable the lifting motor 24 to drive the double-clamping coupling 23, the hollow rod section 13, the solid rod section 12, and the lifting platform 11 to move up and down.

[0047] By raising and lowering the lifting platform assembly, the lifting platform 11 can be embedded in the groove to change the contact gap between the lifting platform 11 and the fixed platform, thereby changing the cooling effect on the lifting platform 11, and in turn changing the cooling effect on the molybdenum wafer stage 16. The growth temperature of the single crystal diamond 18 changes accordingly. This not only avoids the waste of time and personnel caused by repeatedly opening and adjusting the growth substrate, but also ensures temperature-controlled growth of single crystal diamond without reducing power and gas pressure during the synthesis process by raising and lowering the temperature control.

[0048] In addition, a sealing device 22 is installed at the lower end of the copper disc connector 8 and the outside of the hollow rod section 13. The upper and lower ends of the sealing device 22 are respectively sealed and fixedly connected to the outer peripheral surfaces of the copper disc connector 8 and the hollow rod section 13. Specifically, as follows... Figure 5 As shown, the sealing device 22 includes a telescopic cover 22-1 that covers the lower end of the copper disk connector 8 and the hollow rod section 13 and is telescopic. The telescopic cover 22-1 is a bellows. The upper end of the telescopic cover 22-1 is provided with an upper connector that is sealed and fixed to the outer peripheral surface of the copper disk connector 8, and the lower end of the telescopic cover 22-1 is provided with a lower connector that is sealed and fixed to the outer peripheral surface of the hollow rod section 13. This achieves the sealing of the gap between the copper disk connector 8 and the hollow rod section 13. When the hollow rod section 13 moves up and down, it can ensure the vacuum tightness of the interlayer formed by the inner circumference of the copper disk connector 8 and the outer circumference of the hollow rod section 13, thereby ensuring the vacuum tightness inside the MPCVD cavity.

[0049] Furthermore, the upper connector includes an upper collar 22-2 fixed to the upper end of the telescopic cover 22-1 and sleeved on the outside of the copper disc connector 8; an upper nut cap 22-3 sleeved on the outside of the copper disc connector 8 and threadedly connected to the upper part of the upper collar 22-2; and an upper sealing ring 22-4 located at the upper end opening of the upper collar 22-2 and pressed against the outer circumferential surface of the copper disc connector 8 by the upper nut cap 22-3. Through the tight contact between the upper sealing ring 22-4 and the outer circumferential surface of the copper disc connector 8, both sealing between the upper connector and the copper disc connector 8 are achieved, and a fixed connection between the upper connector and the copper disc connector 8 is achieved through static friction. This structure of the upper connector facilitates installation and facilitates sealing and fixing between the upper connector and the copper disc connector 8.

[0050] The lower connector includes a lower collar 22-5 fixed to the lower end of the telescopic cover 22-1 and sleeved on the outside of the hollow rod section 13; a lower nut cap 22-6 sleeved on the outside of the hollow rod section 13 and threaded to the lower part of the lower collar 22-5; and a lower sealing ring 22-7 located at the lower end opening of the lower collar 22-5 and pressed against the outer circumferential surface of the hollow rod section 13 by the lower nut cap 22-6. Through the tight contact between the lower sealing ring 22-7 and the hollow rod section 13, both sealing between the lower connector and the hollow rod section 13 are achieved, and a fixed connection between the lower connector and the hollow rod section 13 is achieved through static friction. This structure of the lower connector facilitates installation and facilitates sealing and fixing between the lower connector and the hollow rod section 13.

[0051] In other embodiments, the upper connector can be a clamp structure, including a two-part clamping ring. The two halves of the clamping ring clamp and fix the upper end of the telescopic cover 22-1 to the outer peripheral surface of the copper disc connecting pipe 8, achieving both sealing and fixation. Alternatively, an upper sealing ring can be provided between the telescopic cover 22-1 and the copper disc connecting pipe 8 to improve the sealing effect. Similarly, in other embodiments, the lower connector can be a clamp structure, including a two-part clamping ring. The two halves of the clamping ring clamp and fix the lower end of the telescopic cover 22-1 to the outer peripheral surface of the hollow rod section 13, achieving both sealing and fixation. Alternatively, a lower sealing ring can be provided between the telescopic cover 22-1 and the hollow rod section 13 to improve the sealing effect. In other embodiments of the growth platform assembly, a cooling water chamber can also be provided inside the lifting platform.

[0052] In other embodiments of the growth stage assembly, a sealing ring may be provided between the fixed rod and the lifting rod to replace the sealing device.

[0053] In other embodiments of the growth stage assembly: the lifting rod may be entirely solid.

[0054] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A growth stage assembly for single-crystal diamond synthesis, comprising a fixed stage assembly and a lifting stage assembly, the fixed stage assembly comprising a fixed stage and a fixed rod connected to the fixed stage and extending downward, the lifting stage assembly comprising a lifting stage and a lifting rod connected to the lifting stage and extending downward, the fixed stage having a groove for the lifting stage to sink into, the lifting rod passing through the fixed stage and the fixed rod and its lower end for connecting a lifting drive device, characterized in that... A guide sleeve is installed on the fixed platform at the position through which the lifting rod passes. The lifting rod is provided with a guide fitting part that cooperates with the inner wall of the guide sleeve to guide the up and down movement of the lifting platform assembly. The fitting clearance between the lifting platform and the groove is sufficient to allow the lifting platform assembly to move up and down smoothly.

2. The growth stage assembly for single-crystal diamond synthesis according to claim 1, characterized in that, The guide fitting part is an annular protrusion protruding on the outer circumferential surface of the lifting rod.

3. The growth stage assembly for single-crystal diamond synthesis according to claim 2, characterized in that, The longitudinal section of the annular protrusion is arc-shaped.

4. The growth stage assembly for single-crystal diamond synthesis according to any one of claims 1 to 3, characterized in that, The guide sleeve has a flange, which is fixed to the mounting plate by screws.

5. The growth stage assembly for single-crystal diamond synthesis according to any one of claims 1 to 3, characterized in that, The guide sleeve is a graphite copper sleeve.

6. The growth stage assembly for single-crystal diamond synthesis according to any one of claims 1 to 3, characterized in that, The lifting platform is a solid platform, and the lifting rod includes a solid rod segment connected to the lifting platform and a hollow rod segment connected below the solid rod segment. The guide fitting part is provided on the solid rod segment.

7. The growth stage assembly for single-crystal diamond synthesis according to any one of claims 1 to 3, characterized in that, The fixed platform includes a copper disk and a copper ring separately disposed on the top surface of the copper disk. The guide sleeve is installed on the copper disk, and the groove is formed by the inner cavity of the copper ring and the top surface of the copper disk.

8. The growth stage assembly for single-crystal diamond synthesis according to claim 7, characterized in that, The copper ring includes an inner copper ring and an outer copper ring arranged in a nested manner. The inner cavity of the inner copper ring and the top surface of the copper disk together form the groove. The upper and lower thickness of the inner copper ring is greater than that of the outer copper ring.

9. The growth stage assembly for single-crystal diamond synthesis according to claim 7, characterized in that, The copper ring is placed on the top surface of the copper plate for easy access.

10. The growth stage assembly for single-crystal diamond synthesis according to any one of claims 1 to 3, characterized in that, A sealing device is installed at the lower end of the fixed rod and the outside of the lifting rod. The upper and lower ends of the sealing device are respectively sealed and fixedly connected to the outer circumference of the fixed rod and the lifting rod.

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