Deposition chamber structure and MPCVD equipment

Abstract

The invention discloses a deposition chamber structure and MPCVD equipment, and belongs to the field of diamond synthesis equipment. According to the technical scheme, the deposition chamber structure comprises a base, a tubular quartz window is fixedly arranged on the base, an upper cover is connected to the upper portion of the quartz window in a sealed mode, a metal ring is arranged on the outer side of the quartz window in a sleeving mode, and a plurality of transversely-arranged and vertically-arranged microwave feed-in gaps are formed in the middle area of the metal ring; the outer side of the middle area of the metal ring is sleeved with a resonance metal cavity, the resonance metal cavity is used for being connected with a microwave source, a growth base table capable of lifting in a multi-stage mode is arranged in the quartz window, the microwave feed-in dimension is increased, and plasma which is large in discharge area, uniform, stable and high in energy density is formed above the growth base table in a coupling mode. And the growth base table can be lifted in a multi-stage manner, so that the deposition quality of the growth sample is optimized, the deposition area of the growth sample is expanded, and the preparation of the high-quality large-size diamond crystal is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond synthesis equipment, and particularly to a deposition chamber structure and an MPCVD equipment. Background Art

[0002] Microwave Plasma Chemical Vapor Deposition (MPCVD) has become the optimal chemical vapor deposition method for artificial diamond synthesis due to its advantages such as high energy density, no internal electrode pollution in the reaction chamber, a variety of process gases, continuous, stable and controllable microwave power, stable and controllable growth temperature field, high purity of the grown diamond crystals, and low defect density.

[0003] MPCVD uses microwave energy to excite gas molecules mainly composed of hydrogen and methane containing diamond precursors, generating a high - concentration plasma. At a temperature of several thousand degrees, methane and hydrogen are cracked into free carbon groups and various ions. The free carbon active groups are adsorbed on the surface of the growth substrate to form a carbon element deposition. In this process, the plasma not only realizes the preparation of diamond growth raw materials but also provides a driving force for the stable transmission of free carbon active groups.

[0004] Existing MPCVD equipment mainly has two chamber structures, a cylindrical chamber structure and a dish - shaped chamber structure. In the cylindrical chamber structure, microwaves enter the reaction chamber in a way of being fed from above the chamber to couple and form a plasma sphere. In the dish - shaped chamber structure, microwaves enter the reaction chamber in a way of being fed from below the chamber to couple and form a plasma sphere. Limited by the chamber shape and structure, microwave feeding method, microwave energy density, microwave discharge area, and poor stability and easy jump of microwave plasma, it is impossible to prepare large - size diamond crystals with high quality and meet the application requirements of users for high - quality large - size diamond crystals. Summary of the Invention

[0005] To solve the technical problem in the above - mentioned background art that the chamber structure of the existing MPCVD equipment is difficult to couple a plasma with higher energy density, larger discharge area, uniform, stable and not easy to jump, resulting in the inability to prepare large - size diamond crystals with high quality, the present invention provides a deposition chamber structure.

[0006] The technical solution of the present invention is as follows: The present invention provides a deposition chamber structure, comprising a base, a tubular quartz window is fixedly provided on the base, an upper cover is sealed and connected above the quartz window, a metal ring is sleeved on the outer side of the quartz window, a plurality of microwave feeding slots arranged horizontally and vertically are arranged in the middle region of the metal ring, a resonant metal cavity is sleeved on the outer side of the middle region of the metal ring, the resonant metal cavity is used to be connected to a microwave source, and a growth base capable of multi-stage lifting and lowering is arranged in the quartz window; the microwave feeding slots arranged horizontally are distributed at intervals along the annular direction of the metal ring, a microwave feeding slot arranged vertically is arranged between every two adjacent microwave feeding slots arranged horizontally, and the microwave feeding slots arranged vertically are located at a position where the metal ring is far away from the microwave source. On one side of the wave source, the microwave feeding gaps arranged horizontally and vertically increase the dimension of microwave feeding, thereby enhancing the overall uniformity of microwave distribution in the resonant metal cavity and the quartz window. The vertically arranged microwave feeding gap is located on the side of the metal ring away from the microwave generator, which can better guide the microwaves to couple from the resonant metal cavity into the quartz window, so that the microwaves can better match the electromagnetic field in the quartz window, reduce reflection and energy loss, and thus improve the coupling efficiency of the microwaves. Combined with the height adjustment of the growth base, the deposition quality of the growth sample is optimized, the deposition area of ​​the growth sample is expanded, and the deposition rate of the growth sample is increased, thereby realizing the preparation of high-quality large-size diamond crystals.

[0007] Preferably, a number of heat dissipation holes are evenly arranged around the upper and lower end areas of the metal ring, and air cooling channels are installed around the bottom of the resonant metal cavity and the lower end area of ​​the metal ring, which can efficiently take away the heat generated by the metal ring and the resonant metal cavity during operation, prevent the degradation of material properties due to excessive temperature, and thus ensure the stability and reliability of the entire deposition chamber structure and extend the service life of the equipment.

[0008] Preferably, a base plate is fixedly provided on the upper cover, a first stroke rod is fixedly installed vertically on the base plate, a first limit plate is fixedly provided on the top of the first stroke rod, the first stroke rod is slidably connected to a motion module, a metal column is fixedly connected to the bottom of the motion module, a first sealing spring bellows is sleeved on the outer side of the metal column, the first sealing spring bellows is fixedly provided between the base plate and the motion module, so as to ensure the sealing of the metal column during the movement and avoid gas leakage in the chamber, the metal column is used for movably inserting into the quartz window, the upper end of the metal column is used for connecting to a bias power supply module, which can apply a suitable bias to the environment in the chamber, regulate the reaction process, and improve the quality and efficiency of diamond crystal deposition.

[0009] Preferably, a second stroke rod is fixedly provided on the motion module. The upper end of the second stroke rod passes through the first limit plate and is fixedly connected to a second limit plate. A first screw rod is threadedly connected to the second limit plate. A probe electrode hermetically connected to the metal column is also fixedly provided on the motion module. The lower end of the first screw rod is used to pass through the first limit plate and connect or disconnect from the probe electrode. The upper end of the first screw rod is connected to the bias power supply module. The position of the first screw rod can be adjusted according to requirements. Furthermore, the metal column can be connected to the bias power supply module through the first screw rod and the probe electrode to meet the connection requirements of metal columns at different positions and the bias power supply module, optimize the electromagnetic field distribution during deposition, and facilitate the preparation of high-quality diamond crystals.

[0010] Preferably, cooling water pipelines are provided inside the motion module, the upper cover, the base, and the growth base table, which can effectively cool and maintain the working temperature of the components stable, avoiding affecting the equipment performance and the diamond crystal deposition quality due to temperature fluctuations. At the same time, a stable temperature environment helps to reduce the mechanical stress caused by the thermal expansion and contraction of the components and extend the overall service life of the equipment.

[0011] Preferably, the growth base table is fixedly installed on the secondary lifting plate. The upper end of the growth base table sequentially passes through the sealing ring and the base and extends into the quartz window. The lower side of the sealing ring is fixedly connected to the primary lifting plate through a third stroke rod. The secondary lifting plate is slidably connected to the third stroke rod. The primary lifting plate is connected to the primary lifting motor, and the primary lifting motor is fixedly installed on the frame. The secondary lifting plate is connected to the secondary lifting motor, and the secondary lifting motor is installed on the primary lifting plate. The primary lifting plate can perform rapid lifting within a large range to meet the requirement of adjusting the approximate position of the growth base table. The secondary lifting plate can achieve precise and fine lifting adjustment. Combining with the advantage of uniform microwave distribution, the height of the growth base table can be precisely adjusted according to different stages of crystal growth, optimizing the crystal growth environment and improving the deposition quality and size of diamond crystals.

[0012] Preferably, a second sealed spring bellows is fixedly provided between the sealing ring and the secondary lifting plate. The second sealed spring bellows covers the area of the growth base table below the sealing ring, ensuring the sealing of the chamber and preventing external gas from entering the deposition chamber to interfere with the crystal growth process. At the same time, it can adaptively expand and contract with the lifting of the growth base table and will not hinder the movement of the growth base table, ensuring the stable operation of the equipment.

[0013] Preferably, the lifting rate of the primary lifting plate is 1 - 100 mm / min, and the lifting rate of the secondary lifting plate is 0.1 - 1000 μm / min. The lifting rate range of the primary lifting plate can quickly adjust the growth base table to a suitable approximate area, improving the operation efficiency. The extremely small lifting rate change range of the secondary lifting plate can achieve fine-tuning of the height of the growth base table, meeting the requirements of highly precise control of the growth environment during the diamond crystal growth process, and thus facilitating the preparation of high-quality and large-sized diamond crystals.

[0014] Preferably, the included angle between two adjacent horizontally arranged microwave feeding slots is 60° to 120°. The horizontally arranged microwave feeding slots can better cooperate with the vertically arranged microwave feeding slots, further optimize the uniformity of the distribution of microwaves in the resonant metal cavity and the quartz window, enhance the matching degree between the microwaves and the electromagnetic field in the cavity, effectively reduce microwave reflection and energy loss, improve the microwave coupling efficiency, and ultimately improve the deposition quality and deposition rate of diamond crystals.

[0015] The present invention provides an MPCVD device that adopts the above-described deposition chamber structure.

[0016] It can be seen from the above technical solutions that the advantages of the present invention are as follows: After the microwaves are transmitted from the microwave source to the resonant metal cavity and resonate, they are uniformly and stably fed into the vacuum quartz window through the horizontally and vertically arranged microwave feeding slots on the metal ring, and a plasma with a large, uniform, stable and high energy density discharge region is coupled above the growth substrate. At the same time, a positive bias voltage electric field is connected above the chamber to further optimize the plasma state, make the plasma more flat and uniform, and greatly improve the nucleation quality, crystal quality and growth rate of the growth sample. The growth substrate is lifted and lowered in multiple stages to control the height of the growth substrate during the growth deposition process. The microwave feeding method is combined with the adjustment of the height of the growth substrate, and with the positive bias voltage electric field connected above the chamber, the deposition quality of the growth sample is optimized, the deposition area of the growth sample is expanded, the deposition rate of the growth sample is increased, and the preparation of high-quality large-size diamond crystals is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 is a schematic diagram of the overall structure of the deposition chamber structure according to one or more embodiments of the present invention; Figure 2 is a schematic diagram of the structure of the metal ring according to one or more embodiments of the present invention Figure 1 ; Figure 3 is a schematic diagram of the structure of the metal ring according to one or more embodiments of the present invention Figure 2 ; The components represented by the reference numerals in the drawings are: 1. Base plate; 2. First stroke rod; 3. First limit plate; 4. Movement module; 5. First sealed spring bellows; 6. Metal column; 7. Second stroke rod; 8. Second limit plate; 9. Probe electrode; 10. First screw; 11. Upper cover; 12. Infrared temperature measurement observation hole; 13. Quartz window; 14. Metal ring; 15. Heat dissipation hole; 16. Microwave feed-in gap; 17. Resonant metal cavity; 18. Air-cooling channel; 19. Base; 20. Sealing ring; 21. Growth base; 22. Second sealed spring bellows; 23. Secondary lifting plate; 24. Second screw; 25. Secondary lifting motor; 26. Third stroke rod; 27. Primary lifting plate; 28. Lifting frame; 29. Primary lifting motor; 30. Fourth stroke rod; 31. Frame. Detailed implementation manner

[0019] To make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the specific embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in this patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this patent.

[0020] Embodiment 1 In a typical implementation manner of the present invention, as Figure 1As shown, a deposition chamber structure is proposed, including: an upper cover 11, a quartz window 13, a metal ring 14, a resonant metal cavity 17, a base 19, and a growth pedestal 21. The base 19 is fixedly installed on a frame 31. The tubular quartz window 13 is a microwave feeding window and a chamber vacuum pressure maintaining component. The height of the quartz window 13 is 200 - 300 mm, and the wall thickness is 1 - 5 mm. The quartz window 13 is placed on the base 19, and the upper cover 11 is placed on the quartz window 13 for contact sealing. An infrared temperature detection observation hole 12 is provided on the side of the upper cover 11 for infrared detection of temperature. The upper and lower ends of the quartz window 13 are hermetically fixed to the contacting base 19 and upper cover 11 through fluororubber rings, facilitating vacuum pumping operation inside the quartz window 13 during subsequent use. The metal ring 14 is sleeved outside the quartz window 13, and the metal ring 14 and the quartz window 13 are coaxially arranged. The lower end of the metal ring 14 is fixedly connected to the base 19 by screws, and the upper end of the metal ring 14 is fixedly connected to the upper cover 11 by screws. A number of heat dissipation holes 15 are evenly provided on the circumferential sides of the upper and lower end regions of the metal ring 14. The heat dissipation holes 15 are straight holes and / or inclined holes with a pore diameter of 1 - 3 mm evenly and densely distributed, and the distribution density of the heat dissipation holes 15 is 4 - 12 pieces / cm². A number of microwave feeding slots 16 are provided on the circumferential side of the middle region of the metal ring 14; the resonant metal cavity 17 is sleeved outside the middle region of the metal ring 14, and a resonant chamber is formed between the resonant metal cavity 17 and the metal ring 14. The resonant metal cavity 17 is used to be connected to a rectangular microwave waveguide, and then connected to a microwave source. The microwave power adjustment range of the microwave source is 0.6 - 12 KW, and the frequency is 2.45 GHz or 915 MHz. An air-cooling channel 18 is installed around the lower part of the resonant metal cavity 17 and the lower end region of the metal ring 14, and the air-cooling channel 18 is connected to a cooling fan for air-cooling operation. The air volume of the cooling fan is 5 - 30 m³ / h; the growth pedestal 21 is arranged to be lifted and lowered inside the quartz window 13, and can change the vertical position of the growth pedestal 21 inside the quartz window 13 according to requirements to adapt to different working needs.

[0021] Specifically, as Figure 2 and Figure 3As shown in the figure, there are several microwave feeding slots 16. The several microwave feeding slots 16 are divided into two types: horizontally arranged and vertically arranged. Among them, the horizontally arranged microwave feeding slots 16 are spaced along the circumferential direction of the metal ring 14. The microwave feeding slot 16 has a length of 50 mm and a width of 3 mm, and the included angle between two adjacent horizontally arranged microwave feeding slots 16 is 60° - 120° (central angle); there is a vertically arranged microwave feeding slot 16 between every two adjacent horizontally arranged microwave feeding slots 16. The vertically arranged microwave feeding slot 16 has a length of 50 mm and a width of 3 mm, and the distance between two adjacent vertically arranged microwave feeding slots 16 is 50 - 100 mm. The vertically arranged microwave feeding slot 16 is located on the side of the metal ring 14 away from the microwave generating device (i.e., the microwave source), that is, there is no vertically arranged microwave feeding slot 16 on the side of the metal ring 14 close to the microwave generating device.

[0022] The microwave feeding slots 16 are divided into two setting methods: horizontal and vertical, which can obtain a plasma with higher energy density, larger discharge area, and better uniformity and stability. Specifically, the horizontally arranged microwave feeding slots 16 are spaced along the circumferential direction of the metal ring 14, which can make the microwave be fed more evenly in the circumferential direction of the metal ring 14. There is a vertically arranged microwave feeding slot 16 between every two adjacent horizontally arranged microwave feeding slots 16, which further increases the dimension of microwave feeding, so that the microwave can also be more evenly distributed in the radial direction of the metal ring 14, thereby enhancing the uniformity of the microwave distribution in the resonant metal cavity 17 and the quartz window 13 as a whole, which is beneficial to improving the consistency of the process at the growth base 21 in the quartz window 13. And the vertically arranged microwave feeding slot 16 is located on the side of the metal ring 14 away from the microwave generating device, which can better guide the microwave to be coupled from the resonant metal cavity 17 into the quartz window 13, make the microwave better match the electromagnetic field in the quartz window 13, reduce reflection and energy loss, thereby improving the coupling efficiency of the microwave, enabling more microwave energy to effectively act on the substances on the growth base 21, and improving the process efficiency and quality.

[0023] The growth substrate stage 21 is composed of a molybdenum sample stage and a water-cooled copper substrate stage, and can realize the homoepitaxial or heteroepitaxial diamond thin films and thick films on diamond substrates with sizes ranging from 1 to 4 inches. The growth rate is 0.1 - 100 μm / h. In this embodiment, the growth substrate stage 21 is a multi-stage lifting structure, which can change its vertical height according to actual needs. Specifically, the growth substrate stage 21 is fixedly installed on a multi-stage lifting drive mechanism. The multi-stage lifting drive mechanism includes a second sealed spring bellows 22, a secondary lifting disk 23, a second screw 24, a secondary lifting motor 25, a third stroke rod 26, a primary lifting disk 27, a lifting frame 28, a primary lifting motor 29, and a fourth stroke rod 30. The primary lifting motor 29 is fixedly installed on the frame 31. The output end of the primary lifting motor 29 is fixedly connected with a driving screw, and the driving screw is threadedly connected with the lifting frame 28. The driving screw is vertically arranged. The primary lifting motor 29 can drive the lifting frame 28 to move vertically through the driving screw. In order to limit the rotation of the lifting frame 28 around the axis, the lifting frame 28 is also slidably connected with the vertically arranged fourth stroke rod 30. The primary lifting disk 27 is fixedly arranged on the lifting frame 28 and can move vertically with the lifting frame 28. The secondary lifting motor 25 is vertically and fixedly installed on the primary lifting disk 27. The output end of the secondary lifting motor 25 is fixedly connected with the second screw 24 to drive the second screw 24 to rotate around the axis. The secondary lifting disk 23 is threadedly connected with the second screw 24, and the secondary lifting disk 23 is also slidably connected with the vertically arranged third stroke rod 26. Thus, under the drive of the secondary lifting motor 25 and the second screw 24, the secondary lifting disk 23 can move vertically in the second stage.

[0024] Specifically, as Figure 1 shown, the primary lifting motor 29 is connected to the lifting frame 28. The primary lifting disk 27 is fixedly installed on the lifting frame 28. The upper end of the fourth stroke rod 30 is fixedly connected to the base 19, and the lower end of the fourth stroke rod 30 is fixedly connected to the frame 31. A sealing ring 20 is provided at the bottom of the base 19 to ensure the sealing between the base 19 and the growth substrate stage 21. The fourth stroke rod 30 vertically passes through the sealing ring 20 and the edge of the primary lifting disk 27. The movement of the primary lifting motor 29 drives the lifting frame 28 to lift, and the lifting frame 28 drives the primary lifting disk 27 to lift within a certain range of the fourth stroke rod 30. Inside the inner side of the fourth stroke rod 30 above the first-level lifting disc 27, a third stroke rod 26 is fixedly installed. The upper end of the third stroke rod 26 is fixed to the lower side of the sealing ring 20, and the lower end of the third stroke rod 26 is fixedly connected to the first-level lifting disc 27. The second-level lifting disc 23 is slidably arranged on the third stroke rod 26. The second sealing spring bellows 22 is fixedly arranged between the sealing ring 20 and the second-level lifting disc 23. The second sealing spring bellows 22 is used to surround the lower region of the growth base 21 (i.e., the region where the growth base 21 is below the sealing ring 20). Specifically, the growth base 21 is installed and fixed on the second-level lifting disc 23. The upper end of the growth base 21 sequentially passes through the sealing ring 20 and the base 19 and extends into the quartz window 13. The second-level lifting motor 25 rotates to drive the second screw rod 24 to rotate, and the second screw rod 24 rotates to drive the second-level lifting disc 23 to lift and lower, and the second-level lifting disc 23 drives the growth base 21 to lift and lower.

[0025] In this embodiment, the stroke range of the first-level lifting disc 27 is 0 - 500 mm, and the lifting rate is 1 - 100 mm / min; the lifting rate of the second-level lifting disc 23 is 0.1 - 1000 μm / min, the regulation range of the height of the growth base 21 is 0 - 100 mm, and the regulation accuracy is 1 μm.

[0026] It can effectively improve the crystal growth efficiency, dynamically adjust the height of the growth base 21 as the height of the sample substrate increases during the growth process, reduce unnecessary start-up and shutdown operations due to replacing different height cushion discs, and can extend the service life of the equipment, and can ensure the growth continuity and uniformity of the same sample substrate, which has a good guarantee for the crystal quality.

[0027] Above the upper cover 11, a bias voltage device is also fixedly provided to connect a positive bias voltage electric field above the chamber, optimize the deposition quality of the growth sample, expand the deposition area of the growth sample, increase the deposition rate of the growth sample, and realize the preparation of high-quality large-size diamond crystals.

[0028] Specifically, the bias voltage device includes a bottom plate 1, a first stroke rod 2, a first limit plate 3, a motion module 4, a first sealed spring bellows 5, a metal column 6, a second stroke rod 7, a second limit plate 8, a probe electrode 9 and a first screw 10. The bottom plate 1 is made of metal and is fixedly installed on the upper cover 11 by screws. There are two first stroke rods 2, and the two first stroke rods 2 are vertically and fixedly arranged on the bottom plate 1. The motion module 4 is made of metal, and both ends of the motion module 4 are slidably connected to the adjacent first stroke rods 2. The tops of the two first stroke rods 2 are fixedly connected by the first limit plate 3, and the first stroke rod 2 and the first limit plate 3 are fixedly connected by welding; the metal column 6 is a molybdenum metal cylinder, and the metal column 6 is vertically and fixedly arranged at the central position of the bottom of the motion module 4. The lower end of the metal column 6 sequentially passes through the central positions of the bottom plate 1 and the upper cover 11 and extends into the quartz window 13. The first sealed spring bellows 5 is sleeved outside the metal column 6. The upper end of the first sealed spring bellows 5 is fixedly connected to the motion module 4, and the lower end of the first sealed spring bellows 5 is fixedly connected to the bottom plate 1 to be used for hermetically wrapping the part of the metal column 6 between the bottom plate 1 and the motion module 4. The motion module 4 is used to play a guiding role when the metal column 6 extends into the quartz window 13 to ensure that the metal column 6 can move vertically.

[0029] There are two second stroke rods 7, and the two second stroke rods 7 are vertically and fixedly arranged on the motion module 4. The lower ends of the second stroke rods 7 are fixedly connected to the motion module 4 by welding. The upper ends of the second stroke rods 7 pass through the first limit plate 3, and the upper ends of the two second stroke rods 7 are fixedly connected by the second limit plate 8. The second stroke rod 7 and the second limit plate 8 are fixedly connected by welding. A first screw 10 is threadedly connected to the second limit plate 8, and the lower end of the first screw 10 passes through the first limit plate 3; the probe electrode 9 is fixedly arranged above the motion module 4, and the probe electrode 9 is hermetically connected to the metal column 6. The lower end of the first screw 10 is used to be connected to the probe electrode 9 and is connected to the metal column 6 through the probe electrode 9. The upper end of the first screw 10 is used to be connected to the bias voltage power module to apply a 50 - 100V positive electric field to the microwave plasma.

[0030] In this embodiment, the air-cooled channel 18, the metal ring 14, the resonant metal cavity 17, the base 19, the sealing ring 20, the first-level lifting disc 27, and the second-level lifting disc 23 are all made of aluminum alloy; cooling water pipelines are provided inside the motion module 4, the upper cover 11, the base 19, and the growth base 21. The cooling water pipelines are connected to a cooling water circulation air conditioner. The temperature of the cooling water is 10 - 35°C, the temperature control range of the cooling water in the cooling water pipelines is 10 - 35°C, the control accuracy is 0.1°C, and the cooling water flow rate ≥ 40L / min. The flow rate and temperature can be controlled by the overall externally connected cooling water circulation air conditioner.

[0031] Embodiment 2 In another typical embodiment of the present invention, an MPCVD device is proposed, which adopts the deposition chamber structure mentioned in Embodiment 1.

[0032] The process of depositing diamond thin film on a 10mm*10mm single crystal diamond substrate using the deposition chamber structure is as follows: Operate the first-level lifting motor 29 to drive the first-level lifting plate 27 to rise. When the sealing ring 20 is in close contact with the base 19, the first-level lifting plate 27 reaches the upper limit of the stroke, and the first-level lifting motor 29 stops operating. Then operate the second-level lifting motor 25 to drive the second screw rod 24 to rotate. The rotation of the second screw rod 24 drives the second-level lifting plate 23 to rise to compress the second sealing spring bellows 22, so as to lift the growth base 21 into the quartz window 13. Place the 10mm*10mm single crystal diamond substrate at the central area of the growth base 21. Fix the upper cover 11 together with the bias device above it on the metal ring 14 by screw sealing. Operate the vacuum pump of the MPCVD device to evacuate the inside of the quartz window 13. As the pressure inside the quartz window 13 gradually decreases, the atmospheric pressure squeezes the motion module 4 downward to compress the first sealing spring bellows 5. As the first sealing spring bellows 5 is gradually compressed, the metal column 6 sealed to the probe electrode 9 is squeezed into the quartz window. After the vacuum pumping is completed, the first sealing spring bellows 5 is completely compressed, and the metal column 6 sealed to the probe electrode 9 stops moving. Rotate the first screw rod 10 above the motion module 4 to make the lower end of the first screw rod 10 press the probe electrode 9, and the upper end of the first screw rod 10 is connected to the bias power supply module. Among them, operate the cooling water circulation air conditioner to set the cooling water circulation temperature to 10-35°C, the cooling water flow rate to ≥40L / min, the air volume of the cooling fan to 5-30m³ / h, introduce the growth atmosphere mixed in proportion, adjust the chamber pressure to 10-250 Torr, operate the microwave source, adjust the microwave power to 0.6KW-12KW, operate the bias power supply module, and set the positive bias voltage to 50-100V.

[0033] As the growth process progresses, the height of the growth sample continuously increases. Operate the multi-level lifting drive mechanism to control the lifting of the growth base 21, so that the growth sample is always in the best position. The regulation range of the height of the growth base 21 is 0-100mm, and the regulation accuracy is 1μm.

[0034] In this embodiment, after microwave is transmitted from a microwave source to a resonant metal cavity 17 through a rectangular waveguide and resonates, it is uniformly and stably fed into a vacuum quartz window 13 through a plurality of microwave feeding slits 16 on a metal ring 14, and a plasma with a large, uniform, stable and high energy density discharge region is coupled above a growth substrate 21. A positive bias electric field is connected above the chamber to further optimize the plasma state, making the plasma flatter and more uniform. The nucleation quality, crystal quality and growth rate of the grown sample are all greatly improved. The growth substrate 21 is installed and fixed on a multi-stage lifting drive mechanism to control the height of the growth substrate 21 during the growth and deposition process. Through the new microwave feeding method, combined with the adjustment of the height of the growth substrate 21 and the positive bias electric field connected above the chamber, the deposition quality of the grown sample is optimized, the deposition area of the grown sample is enlarged, and the deposition rate of the grown sample is increased, realizing the preparation of high-quality large-size diamond crystals.

[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A deposition chamber structure, comprising: Base (19), on which a tubular quartz window (13) is fixedly provided. An upper cover (11) is hermetically connected above the quartz window (13). It is characterized in that a metal ring (14) is sleeved outside the quartz window (13). In the middle area of the metal ring (14), there are a number of horizontally and vertically arranged microwave feeding slits (16). Outside the middle area of the metal ring (14), a resonant metal cavity (17) is sleeved. The resonant metal cavity (17) is used to connect with a microwave source. Inside the quartz window (13), there is a growth substrate (21) that can be lifted in multiple stages; The horizontally arranged microwave feeding slits (16) are distributed at intervals along the circumferential direction of the metal ring (14). Between every two adjacent horizontally arranged microwave feeding slits (16), there is a vertically arranged microwave feeding slit (16). The vertically arranged microwave feeding slit (16) is located on the side of the metal ring (14) away from the microwave source.

2. The deposition chamber structure according to claim 1, wherein On the circumferences of the upper and lower end areas of the metal ring (14), a number of heat dissipation holes (15) are evenly provided. Below the resonant metal cavity (17) and around the lower end area of the metal ring (14), an air-cooling channel (18) is installed.

3. The deposition chamber structure according to claim 1, wherein, On the upper cover (11), a bottom plate (1) is fixedly provided. On the bottom plate (1), a vertically arranged first stroke rod (2) is fixedly installed. At the top of the first stroke rod (2), a first limit plate (3) is fixedly provided. The first stroke rod (2) is slidably connected to a motion module (4). At the bottom of the motion module (4), a metal column (6) is fixedly connected. Outside the metal column (6), a first sealed spring bellows (5) is sleeved. The first sealed spring bellows (5) is fixedly arranged between the bottom plate (1) and the motion module (4). The metal column (6) is used to be movably inserted into the quartz window (13). The upper end of the metal column (6) is used to connect with a bias power supply module.

4. The deposition chamber structure according to claim 3, wherein, On the motion module (4), a second stroke rod (7) is fixedly provided. The upper end of the second stroke rod (7) passes through the first limit plate (3) and is fixedly connected to a second limit plate (8). A first screw (10) is threadedly connected to the second limit plate (8); On the motion module (4), a probe electrode (9) hermetically connected to the metal column (6) is also fixedly provided. The lower end of the first screw (10) is used to pass through the first limit plate (3) and connect or disconnect from the probe electrode (9). The upper end of the first screw (10) is connected to the bias power supply module.

5. The deposition chamber structure according to claim 3, wherein Inside the motion module (4), the upper cover (11), the base (19), and the growth substrate (21), there are all cooling water pipelines.

6. The deposition chamber structure according to claim 1, wherein, The growth pedestal (21) is fixedly installed on the secondary lifting disk (23). The upper end of the growth pedestal (21) sequentially passes through the sealing ring (20) and the base (19) and extends into the quartz window (13). The lower side of the sealing ring (20) is fixedly connected with a primary lifting disk (27) through a third stroke rod (26). The secondary lifting disk (23) is slidably connected with the third stroke rod (26). The primary lifting disk (27) is connected with a primary lifting motor (29). The primary lifting motor (29) is fixedly installed on the frame (31). The secondary lifting disk (23) is connected with a secondary lifting motor (25). The secondary lifting motor (25) is installed on the primary lifting disk (27).

7. The deposition chamber structure according to claim 6, wherein, A second sealed spring bellows (22) is fixedly arranged between the sealing ring (20) and the secondary lifting disk (23). The second sealed spring bellows (22) covers the area of the growth pedestal (21) below the sealing ring (20).

8. The deposition chamber structure according to claim 6, wherein The lifting rate of the primary lifting disk (27) is 1 - 100 mm / min, and the lifting rate of the secondary lifting disk (23) is 0.1 - 1000 μm / min.

9. The deposition chamber structure according to claim 1, wherein The included angle between two adjacent horizontally arranged microwave feeding slots (16) is 60° - 120°.

10. An MPCVD device, characterized in that, The deposition chamber structure as described in any one of claims 1 - 9 is adopted.

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