CN216871891U

CN216871891U - Axial air-cooled multi-mode cylindrical resonant cavity MPCVD device

Info

Publication number: CN216871891U
Application number: CN202123096227.5U
Authority: CN
Inventors: 袁稳; 袁良; 郑华
Original assignee: Chengdu Wenzheng Technology Co ltd
Current assignee: Chengdu Wenzheng Technology Co ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-07-01
Anticipated expiration: 2031-12-10

Abstract

The utility model discloses an axial air-cooled multimode cylindrical resonant cavity MPCVD device, which solves the technical problem that the structure of the conventional cylindrical resonant cavity MPCVD device cannot adapt to high-power growth. The microwave resonance cavity comprises a microwave generating device and a resonance cavity body connected with the microwave generating device; the microwave cavity is internally provided with a stainless steel water-cooling antenna connected with a microwave generating device and an annular quartz window connected with the stainless steel water-cooling antenna, the top and the bottom of the resonant cavity are respectively provided with a heat dissipation mechanism and an exhaust mechanism which are communicated with the resonant cavity, the bottom of the exhaust mechanism is provided with a lifting mechanism, and the top of the lifting mechanism is provided with a growth base station. The utility model adopts an annular quartz window to replace the traditional flat quartz window, and the middle position of the ring is replaced by the stainless steel water-cooling antenna, thereby avoiding the direct bombardment of plasma and the existence of a secondary strong field area in the cavity, being more beneficial to the long-term stable operation of equipment and being suitable for the input of high cavity pressure and high power.

Description

Axial air-cooled multi-mode cylindrical resonant cavity MPCVD device

Technical Field

The utility model belongs to the technical field of diamond synthesis equipment, and particularly relates to an axial air-cooled multi-mode cylindrical resonant cavity MPCVD device.

Background

Microwave Plasma Chemical Vapor Deposition (MPCVD) is the preferred method for producing high quality diamond because compared to other methods for generating plasma, microwave-excited plasma has a series of advantages such as no electrode contamination, good controllability, high plasma density, etc. The key part of the MPCVD device is a resonant cavity for generating microwave plasma, the structure of the resonant cavity directly influences the distribution and excitation degree of the plasma in the MPCVD device, and the microwave medium window is a channel for transmitting microwave and an atmosphere isolation barrier, the installation position and the structure of the microwave medium window directly influence the vacuum sealing performance and silicon pollution formed by plasma bombardment, and further influence the deposition rate of a diamond film and the quality of diamond.

In the existing stage, a frequently-used cylindrical resonant cavity adopts a TM013 resonant mode and a wafer-shaped quartz plate as a microwave window, formed plasmas are located right below the quartz plate and are close to each other, active ions generated by the plasmas severely bombard the quartz plate, and etched silicon atoms pollute growth atmosphere and cause silicon pollution of diamonds. And the baking temperature of the quartz plate subjected to the plasma can reach more than 200 ℃, and a rubber ring used for sealing on the quartz plate is easy to age at high temperature to cause air leakage. In addition, a secondary strong region of the microwave electric field is formed between the quartz plate and the plasma region, when the input microwave power is high or the cavity pressure and the input power are not matched, the secondary strong region inevitably generates secondary plasma and causes etching of the quartz plate, so-called 'ball jumping' occurs, and a serious person burns out a quartz window. Therefore, the practical input microwave power of the cylindrical metal resonator type MPCVD apparatus generally cannot exceed 5 kw.

However, in order to accelerate the growth rate of diamond, the microwave input power has to be further increased, but the etching of the microwave window by the plasma generated under high power is avoided, and the pollution of the etched silicon impurities to the grown diamond is avoided. Accordingly, the present invention is directed to an axial air-cooled MPCVD apparatus with multimode cylindrical resonators, which solves at least some of the above problems.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: the utility model provides an axial air-cooled multimode cylinder resonant cavity MPCVD device, solves the technical problem that the structure of current cylinder resonant cavity MPCVD device can't adapt to high power growth.

In order to realize the purpose, the technical scheme adopted by the utility model is as follows:

an axial air-cooled multi-mode cylindrical resonant cavity MPCVD device comprises a microwave generating device used for microwave emission and a resonant cavity connected with the microwave generating device and used for diamond synthesis; the microwave cavity is internally provided with a stainless steel water-cooled antenna which is connected with a microwave generating device and used for microwave introduction and an annular quartz window which is connected with the stainless steel water-cooled antenna and used for microwave transmission, the top and the bottom of the resonant cavity are respectively provided with a heat dissipation mechanism and an exhaust mechanism which are communicated with the resonant cavity, the bottom of the exhaust mechanism is provided with a lifting mechanism which moves up and down in the exhaust mechanism and the resonant cavity, and the top of the lifting mechanism is provided with a growth base station used for placing diamond.

Furthermore, the microwave generating device comprises a microwave head, a circulator connected with the microwave head, a waveguide tube connected with the circulator, a mode converter and a coaxial wire which are respectively connected with the waveguide tube, wherein the coaxial wire is communicated with the resonant cavity, the middle part of the waveguide tube is provided with a three-pin, the end part of the waveguide tube is provided with a short-circuit piston, and the short-circuit piston is connected with an adjusting handle for controlling the movement of the short-circuit piston.

Furthermore, the resonant cavity comprises a cylindrical resonant cavity wall, a porous resonant cavity top arranged on the top surface of the cylindrical resonant cavity wall and connected with the coaxial line, and a porous resonant cavity bottom arranged on the bottom surface of the cylindrical resonant cavity wall.

Furthermore, the stainless steel water-cooled antenna comprises a main antenna and a conical antenna disc, wherein the main antenna penetrates through the mode converter, the waveguide tube and the coaxial line in sequence and penetrates into the resonant cavity, the conical antenna disc is arranged at the bottom of the main antenna, a process gas inlet tube is arranged in the main antenna, one end of the process gas inlet tube is connected with an external gas cylinder, and the other end of the process gas inlet tube penetrates through the conical antenna disc and extends into the inner resonant cavity.

Furthermore, the upper end face and the lower end face of the annular quartz window are respectively connected with the conical antenna disc and the porous resonant cavity bottom in a sealing mode through sealing rings.

Furthermore, a plurality of observation windows are distributed on the wall of the cylindrical resonant cavity, a plurality of heat dissipation through holes are uniformly distributed on the top of the porous resonant cavity, a through hole for the main antenna to penetrate is formed in the center of the top of the porous resonant cavity, and a plurality of exhaust through holes are uniformly distributed at the bottom of the porous resonant cavity.

Furthermore, the heat dissipation mechanism comprises a heat dissipation air box and a heat dissipation fan, wherein the heat dissipation air box is covered on the top surface of the porous resonant cavity top, and the heat dissipation fan is connected with the heat dissipation air box.

Furthermore, the exhaust mechanism comprises a transition cavity body arranged on the bottom surface of the porous resonant cavity and an exhaust port arranged on the outer wall of the transition cavity body.

Furthermore, a lifting cavity is arranged in the transition cavity, and a lifting through hole communicated with the lifting cavity is formed in the bottom of the porous resonant cavity.

Furthermore, elevating system includes the vacuum bellows that is linked together with the transition cavity, locate the water-cooling pipe in vacuum bellows and the lift intracavity, locate the water-cooling pipe top and be used for placing the water-cooling elevating platform of growth base station and locate the linear electric motor that the water-cooling pipe bottom is used for driving water-cooling pipe and water-cooling elevating platform to go up and down.

Compared with the prior art, the utility model has the following beneficial effects:

the utility model has simple structure, scientific and reasonable design and convenient use, solves the technical problem that the structure of the existing cylindrical resonant cavity MPCVD device can not adapt to high-power growth, adopts an annular quartz window to replace the traditional flat quartz window, and the middle position of the ring is replaced by a stainless steel water-cooling antenna, thereby avoiding the direct bombardment of plasma and the existence of a secondary strong field area in the cavity, avoiding the phenomenon of 'ball jumping', and being more beneficial to the long-term stable operation of equipment; the structure of the device can be suitable for high-cavity pressure and high-power input, and the convenience of operation and the universality of operation are greatly improved.

The utility model comprises a microwave generating device and a resonant cavity, wherein the microwave generating device inputs emitted microwaves into the resonant cavity, and internal gas is excited into plasma by utilizing a microwave electric field for the growth of diamond. The stainless steel water-cooling antenna is arranged in the resonant cavity body and connected with the annular quartz window, and the plasma generated by excitation is located below the stainless steel water-cooling antenna and inside the ring of the annular quartz window, so that the situation that the plasma directly irradiates the flat surface of the flat quartz window in the traditional structure is avoided, the direct bombardment of the plasma on the quartz window and the existence of a secondary strong field area in the cavity can be effectively avoided, and the operation stability and the safety of equipment are improved. Meanwhile, because strong silicon pollution of plasma under high power is not considered, the microwave input power can be increased, the pressure in the cavity can be increased to accelerate the growth of the diamond, and the production efficiency of enterprises can be improved.

The top and the bottom of the resonant cavity are respectively provided with a heat dissipation mechanism and an exhaust mechanism, and the bottom of the exhaust mechanism is provided with a lifting mechanism. The heat dissipation mechanism can be matched with a stainless steel water-cooled antenna to realize rapid heat dissipation and cooling in the resonant cavity body through water cooling and air cooling, the exhaust mechanism can exhaust gas in the resonant cavity body to realize rapid pressure reduction, and the lifting mechanism can ensure the stable growth of diamond in different growth processes. The heat dissipation mechanism, the exhaust mechanism and the lifting mechanism can greatly improve the convenience of operation and the universality of operation, and simplify the production operation.

Drawings

FIG. 1 is a schematic view of the structure of the present invention.

FIG. 2 is a top view of the multi-hole resonator according to the present invention.

FIG. 3 is a structural diagram of the bottom of the porous resonator according to the present invention.

FIG. 4 is a diagram of the construction of the annular quartz window of the present invention.

Wherein, the names corresponding to the reference numbers are:

1-microwave generating device, 2-resonant cavity, 3-stainless steel water-cooled antenna, 4-plasma, 5-annular quartz window, 6-heat dissipation mechanism, 7-exhaust mechanism, 8-lifting mechanism, 9-growth base station, 11-microwave head, 12-circulator, 13-waveguide tube, 14-mode converter, 15-coaxial line, 16-three-pin, 17-short circuit piston, 18-adjusting handle, 21-cylindrical resonant cavity wall, 22-porous resonant cavity top, 23-porous resonant cavity bottom, 31-main antenna, 32-conical antenna disc, 33-process gas inlet pipe, 61-heat dissipation air box, 62-heat dissipation fan, 71-transition cavity, 72-exhaust port, 73-lifting cavity, 81-vacuum bellows, 82-water-cooled round tube, 83-water-cooled lifting platform, 84-linear motor, 211-observation window, 221-heat dissipation through hole, 222-through hole, 231-exhaust through hole and 232-lifting through hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the utility model, and not restrictive of the full scope of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and thus, it should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; of course, mechanical connection and electrical connection are also possible; alternatively, they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1-4, the axial air-cooled multi-mode cylindrical resonant cavity MPCVD device provided by the present invention has a simple structure, a scientific and reasonable design, and a convenient use, and solves the technical problem that the structure of the existing cylindrical resonant cavity MPCVD device cannot adapt to high power growth, and adopts an annular quartz window 5 to replace the traditional flat quartz window, and the middle position of the annular quartz window is replaced by a stainless steel water cooling antenna 3, so that the direct bombardment of plasma 4 and the existence of a secondary strong field area in the cavity are avoided, the phenomenon of "ball jump" does not occur, and the long-term stable operation of the device is facilitated; the structure of the device can be suitable for high-cavity pressure and high-power input, and the convenience of operation and the universality of operation are greatly improved.

The utility model comprises a microwave generating device 1 for microwave emission and a resonant cavity 2 connected with the microwave generating device 1 and used for diamond synthesis; a stainless steel water-cooled antenna 3 connected with a microwave generating device 1 and used for microwave introduction, a plasma 4 arranged below the stainless steel water-cooled antenna 3 and an annular quartz window 5 connected with the stainless steel water-cooled antenna 3 and used for microwave transmission are arranged in the resonant cavity 2, a heat dissipation mechanism 6 and an exhaust mechanism 7 communicated with the resonant cavity 2 are respectively arranged at the top and the bottom of the resonant cavity 2, a lifting mechanism 8 moving up and down in the exhaust mechanism 7 and the resonant cavity 2 is arranged at the bottom of the exhaust mechanism 7, and a growth base station 9 used for placing diamond is arranged at the top of the lifting mechanism. The microwave generating device 1 inputs the emitted microwaves into the resonant cavity 2, and the internal gas is excited into plasma 4 by the microwave electric field for the growth of the diamond. Be equipped with stainless steel water-cooling antenna 3 in resonant cavity 2, stainless steel water-cooling antenna 3 is connected with annular quartz window 5, and the plasma 4 that arouses the production is located stainless steel water-cooling antenna 3 below and the annular inside of annular quartz window 5, has avoided the dull and stereotyped face of plasma direct irradiation dull and stereotyped quartz window in traditional structure, can effectively avoid the plasma to the direct bombardment of quartz window and the existence of the strong field area of cavity time, has improved the operating stability and the security of equipment. Meanwhile, because strong silicon pollution of plasma under high power is not considered, the microwave input power can be increased, the pressure in the cavity can be increased to accelerate the growth of the diamond, and the production efficiency of enterprises can be improved. In addition, the heat dissipation mechanism 6, the exhaust mechanism 7 and the lifting mechanism 8 can greatly improve the convenience of operation and the universality of operation, and simplify the production operation. The heat dissipation mechanism 6 can be matched with the stainless steel water-cooled antenna 3 to realize rapid heat dissipation and cooling in the resonant cavity 2 through water cooling and air cooling, the exhaust mechanism 7 can realize rapid depressurization through gas exhaust in the resonant cavity 2, and the lifting mechanism 8 can ensure stable growth of diamond in different growth processes.

The microwave generating device 1 comprises a microwave head 11, a circulator 12 connected with the microwave head 11, a waveguide tube 13 connected with the circulator 12, and a mode converter 14 and a coaxial wire 15 which are respectively connected with the waveguide tube 13, wherein the coaxial wire 15 is communicated with a resonant cavity 2, the middle part of the waveguide tube 13 is provided with a three-pin 16, the end part of the waveguide tube 13 is provided with a short-circuit piston 17, and the short-circuit piston 17 is connected with an adjusting handle 18 for controlling the movement of the short-circuit piston 17. The microwave generated by the microwave head 11 is output into the waveguide 13 through the circulator 12, the microwave energy is transmitted into the resonant cavity 2 through the mode converter 14 and the coaxial line 15, and the plasma is excited for diamond growth under the appropriate gas pressure and microwave power matching. The circulator 12 has a one-way passing function, and can absorb the microwave reflected from the resonant cavity 2 by using a water load, so that the reflected microwave is prevented from entering the magnetron, and the damage of the magnetron is avoided. While the three pins 16 and the short-circuit piston 17 can be used to adjust the impedance matching at no power and gas pressure, so that microwave energy is fed into the resonant cavity 2 as far as possible, reducing the microwave losses.

The resonant cavity 2 comprises a cylindrical resonant cavity wall 21, a porous resonant cavity top 22 arranged on the top surface of the cylindrical resonant cavity wall 21 and connected with the coaxial line 15, and a porous resonant cavity bottom 23 arranged on the bottom surface of the cylindrical resonant cavity wall 1. The cylindrical cavity wall 21 is uniformly provided with a plurality of observation windows 211 so as to observe the form of the plasma 4 inside the cavity 2, the condition of diamond, the growth temperature and the like.

The utility model has the advantages of high power and low silicon pollution, and the annular quartz window 5 is adopted to replace the traditional flat quartz window, thus effectively avoiding the bombardment of the quartz window and further improving the microwave input power; meanwhile, the utility model also improves the water-cooling antenna, can effectively increase the deposition area and improve the growth rate of the diamond. The stainless steel water-cooled antenna 3 comprises a main antenna 31 and a conical antenna disc 32 arranged at the bottom of the main antenna 31, wherein the main antenna 31 penetrates out through a waveguide tube 13 and a coaxial wire 15, microwaves in a mode converter 14 can be effectively input into a resonant cavity 2, the input microwaves are further reflected by a conical surface of the conical antenna disc 32 and are converged to a strong electric field area right below the main antenna 31 to excite plasma, the input microwave power is greatly improved, the microwave power can reach 15-20 kw, and the synthesis efficiency of diamond is further improved; meanwhile, the improvement of the power can also effectively increase the deposition area, so that the deposition area is increased from the original 2 inches to 4 inches. According to the utility model, the annular quartz window 5 is arranged below the stainless steel water-cooled antenna 3, and the upper end face and the lower end face of the annular quartz window 5 are respectively connected with the conical antenna disc 32 and the porous resonant cavity bottom 23 in a sealing manner through the sealing ring, so that the direct bombardment of the plasma 4 below the stainless steel water-cooled antenna 3 below the stainless steel water-cooled antenna is effectively avoided by the annular structure, the sealing ring is far away from the high-temperature environment of the plasma 4, the damage of high temperature to the sealing ring is relieved, and the sealing safety is improved.

The utility model has the advantage of rapid heat dissipation and cooling, and adopts the heat dissipation mechanism 6 and the stainless steel water-cooling antenna 3 to realize rapid heat dissipation and cooling in the resonant cavity body by water cooling and air cooling. Since diamond growth generates a large amount of heat, a heat dissipation and cooling operation is required for this purpose. Because the stainless steel water-cooling antenna 3 is internally provided with the internal water channel, the stainless steel water-cooling antenna can be cooled by circulating water, and the traditional quartz window rarely has a heat dissipation function, so that the air-cooling heat dissipation of the annular quartz window 5 can be realized by the heat dissipation mechanism 6. The heat dissipation mechanism 6 includes a heat dissipation bellows 61 covering the top surface of the porous resonant cavity top 22, and a heat dissipation fan 62 connected to the heat dissipation bellows 61. The top 22 of the porous resonant cavity is uniformly provided with a plurality of heat dissipation through holes 221, the bottom 23 of the porous resonant cavity is uniformly provided with a plurality of exhaust through holes 231, and the heat dissipation through holes 221 and the exhaust through holes 231 are convenient for air flow to flow through. The heat dissipation fan 62 can suck the external air into the resonant cavity 2 from the exhaust through hole 231 of the porous resonant cavity bottom 23, and the external air flows through the surface of the annular quartz window 5, and then enters the heat dissipation air box 61 from the heat dissipation through hole 221 of the porous resonant cavity top 22, and the purpose of heat dissipation of the annular quartz window 5 is achieved by continuous air intake and air outtake. Because the air flows along the surface of the annular quartz window 5 in the axial direction, the resonant cavity 2 is also called as an axial-flow air-cooled microwave plasma cavity.

The utility model has the advantage of rapid depressurization, the gas in the resonant cavity 2 can be rapidly exhausted by adopting the exhaust mechanism 7, and the exhaust mechanism 7 comprises a transition cavity 71 arranged on the bottom surface of the porous resonant cavity bottom 23 and an exhaust port 72 arranged on the outer wall of the transition cavity 71. A process gas inlet pipe 33 is arranged in the main antenna 31, one end of the process gas inlet pipe 33 is connected with an external gas cylinder, and the other end of the process gas inlet pipe 33 extends into the inner resonant cavity 2 through the conical antenna disc 32. The process gas is introduced into the center of the resonant cavity 2 from the process gas inlet pipe 33, enters the transition cavity 71 from the exhaust through holes 231 uniformly distributed on the lower part of the plasma 4, and is exhausted through the exhaust port 72. The exhaust ports 72 may be provided in two and symmetrically distributed about the axis of the transition chamber 71, the gas flow arrangement of the axisymmetric inlet and exhaust gas increasing the uniformity of plasma deposition to some extent. The exhaust port 72 is provided with an exhaust valve for opening and closing the exhaust port 72, and the exhaust port 72 can be externally connected with an air pump for accelerating the exhaust of air.

The utility model has the advantage of stable growth of the diamond, and the lifting mechanism 8 is used for the height of the growth base station 9, thereby ensuring the stability of the diamond in different growth processes. A lifting cavity 73 is arranged in the transition cavity 71, and a lifting through hole 232 communicated with the lifting cavity 73 is arranged at the bottom 23 of the porous resonant cavity. The lifting mechanism 8 comprises a vacuum corrugated pipe 81 communicated with the transition cavity 71, a water-cooling round pipe 82 arranged in the vacuum corrugated pipe 81 and the lifting cavity 73, a water-cooling lifting platform 83 arranged at the top of the water-cooling round pipe 82 and used for placing the growth base platform 9, and a linear motor 84 arranged at the bottom of the water-cooling round pipe 82 and used for driving the water-cooling round pipe 82 and the water-cooling lifting platform 83 to lift. The linear motor 84 can drive the water-cooling circular tube 82 and the water-cooling lifting platform 83 to move up and down so as to adjust the distance between the diamond on the growth base station 9 and the plasma 4. When the thickness of the diamond is increased, the distance between the plasma 4 and the surface of the diamond is increased by reducing the height of the growth base 9 to maintain a proper growth temperature, and the continuous growth of the super-thick diamond can be realized. The vacuum bellows 81 is also retractable, which ensures the adjustment of the growth base 9 and the vacuum sealing performance.

The microwave head 11, the circulator 12, the waveguide 13, the mode converter 14, the coaxial line 15, the three pins 16, the heat dissipation fan 62, the vacuum bellows 81 and the linear motor 84 used in the present invention are all known electrical devices, and can be purchased and used directly in the market, and the structure, circuit and control principle thereof are all known in the prior art, so the structure, circuit and control principle of the microwave head 11, the circulator 12, the waveguide 13, the mode converter 14, the coaxial line 15, the three pins 16, the heat dissipation fan 62, the vacuum bellows 81 and the linear motor 84 are not described herein again.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, but not to limit the technical solutions, and certainly not to limit the patent scope of the present invention; while the utility model has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; that is, the technical problems to be solved by the present invention, which are not substantially changed or supplemented by the spirit and the concept of the main body of the present invention, are still consistent with the present invention and shall be included in the scope of the present invention; in addition, the technical scheme of the utility model is directly or indirectly applied to other related technical fields, and the technical scheme is included in the patent protection scope of the utility model.

Claims

1. The utility model provides an axial air-cooled multimode cylinder resonant cavity MPCVD device which characterized in that: comprises a microwave generating device (1) for microwave emission and a resonant cavity (2) connected with the microwave generating device (1) and used for diamond synthesis; be equipped with in resonant cavity (2) and link to each other stainless steel water-cooling antenna (3) that are used for the leading-in microwave of microwave generating device (1), and link to each other annular quartz window (5) that are used for microwave transmission with stainless steel water-cooling antenna (3), resonant cavity (2) top and bottom are equipped with heat dissipation mechanism (6) and exhaust mechanism (7) that are linked together with resonant cavity (2) respectively, exhaust mechanism (7) bottom is equipped with elevating system (8) that reciprocate in exhaust mechanism (7) and resonant cavity (2), the elevating system top is equipped with growth base station (9) that are used for placing the diamond.

2. The axially air-cooled MPCVD device with multi-mode cylindrical resonator according to claim 1, wherein: the microwave generating device (1) comprises a microwave head (11), a circulator (12) connected with the microwave head (11), a waveguide tube (13) connected with the circulator (12), and a mode converter (14) and a coaxial wire (15) which are respectively connected with the waveguide tube (13), wherein the coaxial wire (15) is communicated with the resonant cavity (2), the middle part of the waveguide tube (13) is provided with a three-pin (16), the end part of the waveguide tube (13) is provided with a short-circuit piston (17), and the short-circuit piston (17) is connected with an adjusting handle (18) for controlling the movement of the short-circuit piston (17).

3. The axially air-cooled MPCVD device with multimode cylindrical resonator according to claim 2, wherein: the resonant cavity (2) comprises a cylindrical resonant cavity wall (21), a porous resonant cavity top (22) arranged on the top surface of the cylindrical resonant cavity wall (21) and connected with the coaxial line (15), and a porous resonant cavity bottom (23) arranged on the bottom surface of the cylindrical resonant cavity wall (21).

4. The axial air-cooled multi-mode cylindrical resonator MPCVD apparatus according to claim 3, wherein: the stainless steel water-cooled antenna (3) comprises a main antenna (31) which sequentially penetrates through the mode converter (14), the waveguide tube (13) and the coaxial line (15) and penetrates into the resonant cavity (2), and a conical antenna disc (32) arranged at the bottom of the main antenna (31); a process gas inlet pipe (33) is arranged in the main antenna (31), one end of the process gas inlet pipe (33) is connected with an external gas cylinder, and the other end of the process gas inlet pipe (33) penetrates through the conical antenna disc (32) and extends into the inner resonant cavity (2).

5. The axial air-cooled multi-mode cylindrical resonator MPCVD apparatus according to claim 4, wherein: the upper end face and the lower end face of the annular quartz window (5) are respectively connected with the conical antenna disc (32) and the porous resonant cavity bottom (23) in a sealing mode through sealing rings.

6. The axial air-cooled MPCVD device with multi-mode cylindrical resonator according to claim 4, wherein: cylindrical cavity wall (21) equipartition is equipped with a plurality of observation window (211), and porous cavity roof (22) equipartition is equipped with a plurality of heat dissipation through-hole (221), and porous cavity roof (22) center is equipped with through-hole (222) that are used for main antenna (31) to wear to establish, and porous cavity bottom (23) equipartition is equipped with a plurality of exhaust through-hole (231).

7. The axially air-cooled MPCVD device with multi-mode cylindrical resonator according to claim 3, wherein: the heat dissipation mechanism (6) comprises a heat dissipation air box (61) which is covered on the top surface of the porous resonant cavity top (22) and a heat dissipation fan (62) which is connected with the heat dissipation air box (61).

8. The axially air-cooled MPCVD device with multimode cylindrical resonator according to claim 7, wherein: the exhaust mechanism (7) comprises a transition cavity (71) arranged on the bottom surface of the porous resonant cavity bottom (23) and an exhaust port (72) arranged on the outer wall of the transition cavity (71).

9. The axially air-cooled MPCVD device with multi-mode cylindrical resonator according to claim 8, wherein: a lifting cavity (73) is arranged in the transition cavity (71), and a lifting through hole (232) communicated with the lifting cavity (73) is arranged at the bottom (23) of the porous resonant cavity.

10. The axially air-cooled MPCVD device with multimode cylindrical resonator according to claim 9, wherein: the lifting mechanism (8) comprises a vacuum corrugated pipe (81) communicated with the transition cavity (71), a water-cooling round pipe (82) arranged in the vacuum corrugated pipe (81) and the lifting cavity (73), a water-cooling lifting platform (83) arranged at the top of the water-cooling round pipe (82) and used for placing the growth base platform (9), and a linear motor (84) arranged at the bottom of the water-cooling round pipe (82) and used for driving the water-cooling round pipe (82) and the water-cooling lifting platform (83) to lift.