CN211005615U

CN211005615U - Waveguide assembly and microwave plasma chemical vapor deposition device

Info

Publication number: CN211005615U
Application number: CN201920996485.2U
Authority: CN
Inventors: 郭兴星; 吴啸; 徐帅; 常豪锋
Original assignee: Zhengzhou Research Institute for Abrasives and Grinding Co Ltd
Current assignee: Jinggong Ruiyi Technology Henan Co ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-07-14
Anticipated expiration: 2029-06-28

Abstract

The utility model relates to a microwave plasma chemical vapor deposition technical field especially relates to a waveguide subassembly and microwave plasma chemical vapor deposition device, the waveguide subassembly includes the induced air pipeline section, a be used for setting up between microwave generator and mode converter, be provided with the induced air passageway on the induced air pipeline section lateral wall, a be used for communicateing induced air pipeline section inner chamber and external, still include the fan, dock with the induced air passageway, a be used for supplying air in induced air pipeline section inner chamber in induced air passageway department, perhaps induced draft from induced air pipeline section inner chamber, with form the air current in the waveguide inner chamber, induced air pipeline section internal stability has the wave-transparent deep bead, a flow direction microwave generator is used for blockking the air current. During operation, through the air supply or the induced draft of fan for the core part in the device is cooled off in the device can be got into to external cold air, ensures that the device can work steadily.

Description

Waveguide assembly and microwave plasma chemical vapor deposition device

Technical Field

The utility model relates to a microwave plasma chemical vapor deposition technical field especially relates to a waveguide subassembly and microwave plasma chemical vapor deposition device.

Background

Microwave Plasma Chemical Vapor Deposition (MPCVD) is the most effective method for preparing high-quality diamond products, and is the preferred method for preparing high-speed, large-area and high-quality diamond films. According to international regulations, there are mainly two industrial MPCVD apparatuses, which are: a low-power MPCVD device with microwave frequency of 2.45GHz and 6-8kW and a high-power MPCVD device with microwave frequency of 915MHz and 60-100 kW.

For example, the chinese patent publication No. CN104726850B discloses a microwave plasma chemical vapor deposition apparatus, which can generate microwaves with a frequency of 915MHz during operation, and has the characteristics of large deposition area and high production efficiency. However, in the operation process of the high-power MPCVD device with the microwave frequency of 915MHz, the transmitted microwave energy is large, which causes the temperature of core components such as a converter and a resonant cavity to be high, not only is the deposition of high-speed and high-quality diamond products unfavorable, but also the service life of related components is reduced, and the stability of the device operation is adversely affected.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a waveguide assembly to its core component appears the high temperature easily and leads to the unstable technical problem of microwave plasma chemical vapor deposition device running state in the microwave plasma chemical vapor deposition device operation process among the solution prior art. An object of the utility model is to provide a microwave plasma chemical vapor deposition device to its core component appears the high temperature easily and leads to the unstable technical problem of microwave plasma chemical vapor deposition device running state in the microwave plasma chemical vapor deposition device operation process among the solution prior art.

In order to achieve the above object, the utility model discloses well waveguide assembly adopts following technical scheme:

a waveguide assembly comprises an induced draft pipe section, an induced draft channel and a fan, wherein the induced draft channel is arranged between a microwave generator and a mode converter for transmitting microwaves, the side wall of the induced draft pipe section is provided with an induced draft channel used for communicating the inner cavity of the induced draft pipe section with the outside, the fan is in butt joint with the induced draft channel and used for supplying air to the inner cavity of the induced draft pipe section at the induced draft channel or sucking air from the inner cavity of the induced draft pipe section to form cooling air flow in the inner cavity of the induced draft pipe section, and a wave-transparent wind shield is fixedly arranged in the induced draft pipe section and used for blocking the air flow from flowing to the.

The beneficial effects of the utility model reside in that: an induced air channel is arranged on the side wall of a waveguide assembly arranged between a microwave generator and a mode converter and is in butt joint with a fan, when the fan works, external cold air is blown into an inner cavity of an induced air pipe section, the cold air can flow to the mode converter through the inner cavity of the induced air pipe section, components such as the mode converter, a resonant cavity and the like are cooled, meanwhile, a wave-transmitting wind shield is arranged in the inner cavity of the induced air pipe section, the wave-transmitting wind shield cannot obstruct microwaves generated by the microwave generator, meanwhile, cooling airflow flowing into the inner cavity of the induced air pipe section through the induced air channel can be obstructed, the cooling airflow cannot flow to the microwave generator, and therefore the three-pin tuner, the microwave generator and the like are prevented from being polluted by dust mixed in the cooling airflow. Similarly, when the fan sucks air from the inner cavity of the induced draft pipe section, the air pressure in the microwave plasma chemical vapor deposition device using the waveguide assembly is lower than the external air pressure, external cold air can enter the device from the corresponding ventilation channel, and the core component of the device is cooled, so that the core component in the microwave plasma chemical vapor deposition device using the waveguide assembly is cooled, and the normal and stable work of the microwave plasma chemical vapor deposition device is ensured.

Furthermore, the air inducing channels are air inducing holes which are arranged in an array mode, and fan flanges used for installing the fans are arranged at the air inducing holes.

Has the advantages that: the structure of the induced air channel is simplified by directly arranging the induced air hole on the side wall of the induced air pipe section, so that the structure of the waveguide assembly is simplified.

Furthermore, the fan supplies air to the air induction pipe section at the air induction hole, and the air induction pipe section is also provided with a liquid cooling system for cooling the air induction pipe section.

Has the advantages that: the liquid cooling system is arranged on the air induction pipe section, so that the air induction pipe section has lower temperature, the fan supplies air at the air induction hole, air flow entering the inner cavity of the air induction pipe section from the air induction hole can be cooled by the air induction pipe section with lower temperature, and air flow flowing to core components such as a converter, a reaction chamber and the like has lower temperature and better cooling effect.

Furthermore, the induced air pipe section is a split rectangular pipe structure and comprises an upper waveguide plate, a lower waveguide plate, a left waveguide plate and a right waveguide plate, the induced air channel is arranged on the upper waveguide plate, the liquid cooling system comprises cooling liquid tanks arranged on the left waveguide plate, the right waveguide plate and the lower waveguide plate, groove cover plates are hermetically arranged on the cooling liquid tanks, and cooling liquid inlets and cooling liquid outlets are formed in the groove cover plates.

Has the advantages that: the air induction pipe section is arranged to be a split structure with the upper waveguide plate, the lower waveguide plate, the left waveguide plate and the right waveguide plate being relatively independent, each waveguide plate is convenient to process and manufacture, particularly the cooling liquid tank is arranged, each waveguide plate can be processed by the cooling liquid tank, and then the waveguide plates are assembled together to form the waveguide assembly.

Furthermore, the cooling liquid groove formed in the left waveguide plate is of a U-shaped structure, the groove cover plate is a U-shaped structure cover plate matched with the shape of the cooling liquid groove, a bolt through hole is formed in the middle of the U-shaped structure of the cooling liquid groove and used for penetrating and installing a bolt for fixing the wave-transmitting wind shield, and the structure of the right waveguide plate is the same as that of the left waveguide plate.

Has the advantages that: the cooling liquid tank is set to be of a U-shaped structure, the distribution density of the cooling liquid tank on the waveguide plate is increased, meanwhile, the middle part of the cooling liquid tank of the U-shaped structure is used for being provided with screw holes for penetrating and installing screws for fixing the wave-transparent wind shield, and the middle space of the cooling liquid tank is used, so that the whole waveguide assembly is more compact in structure. Meanwhile, the structure of the right waveguide plate is the same as that of the left waveguide plate, so that the left waveguide plate and the right waveguide plate can be used universally, and only one waveguide plate with one structure is produced during production aiming at the left waveguide plate and the right waveguide plate, so that the waveguide assembly is more convenient to produce.

The utility model provides a rate microwave plasma chemical vapor deposition device's technical scheme as follows:

a microwave plasma chemical vapor deposition device comprises a microwave generator, a mode converter, an outer cavity forming a resonant cavity, a reaction chamber, a communicated waveguide structure arranged between the microwave generator and the mode converter for conducting microwave, the outer cavity and the mode converter are butted, the reaction chamber is positioned in the outer cavity, the communicating waveguide structure comprises a waveguide assembly, the waveguide assembly comprises an induced draft pipe section which is arranged between the microwave generator and the mode converter to conduct microwave, an induced draft channel is arranged on the side wall of the induced draft pipe section, used for communicating the inner cavity of the induced draft pipe section with the outside, and also comprises a fan which is butted with the induced draft channel and used for supplying air to the inner cavity of the induced draft pipe section at the induced draft channel, or sucking air from the inner cavity of the induced draft pipe section to form cooling air flow in the inner cavity of the induced draft pipe section, wherein a wave-transmitting wind shield is fixedly arranged in the induced draft pipe section and used for blocking the air flow from flowing to the microwave generator; the outer cavity is provided with a ventilation channel which is used for communicating the resonant cavity with the outside, the ventilation channel is communicated with the induced air channel in the waveguide assembly through the resonant cavity, the mode converter and the communicating waveguide structure, when the fan supplies air to the inner cavity of the induced air pipe section at the induced air channel, the ventilation channel is used for discharging air so as to form cooling air flow between the induced air channel and the ventilation channel, or when the fan sucks air from the inner cavity of the induced air pipe section, the ventilation channel is used for supplying air so as to form cooling air flow between the induced air channel and the ventilation channel.

The beneficial effects of the utility model reside in that: an air inducing channel is arranged on the side wall of the waveguide assembly arranged between the microwave generator and the mode converter and is in butt joint with a fan, when the fan works, external cold air is blown into an inner cavity of the air inducing pipe section, and the cold air flows to core components such as the mode converter, the plasma deposition chamber, an outer cavity and the like through the inner cavity of the air inducing pipe section and flows out of the ventilation channel so as to cool the microwave plasma chemical vapor deposition device. Meanwhile, the wave-transmitting wind shield is arranged in the inner cavity of the induced draft pipe section, the wave-transmitting wind shield cannot obstruct microwaves generated by the microwave generator, and meanwhile, cooling airflow flowing into the inner cavity of the induced draft pipe section through the induced draft channel can be obstructed, so that the cooling airflow cannot flow to the microwave generator, and therefore, the microwave generator is prevented from being polluted by dust mixed in the cooling airflow. Similarly, when the fan sucks air from the inner cavity of the induced air pipe section at the induced air channel, the air pressure in the high-power microwave plasma chemical vapor deposition device using the waveguide assembly is lower than the external air pressure, external cold air can enter the outer cavity from the ventilation channel and flows out from the induced air channel to cool core components in the microwave plasma chemical vapor deposition device, and the microwave plasma chemical vapor deposition device is ensured to normally and stably work.

Furthermore, the induced draft pipe section has a length extending direction corresponding to the microwave transmission direction, the wave-transparent wind shield is obliquely arranged, and the wave-transparent wind shield corresponds to the induced draft channel in the length extending direction of the induced draft pipe section.

Has the advantages that: the wave-transparent wind shield is obliquely arranged and corresponds to the induced air channel in the length extending direction of the induced air pipe section, so that the wave-transparent wind shield forms a slope towards the mode converter in the waveguide inner cavity, and when the fan supplies air to the inner cavity of the induced air pipe section at the induced air channel, the slope guides airflow to flow towards the mode converter.

Furthermore, the air inducing channels are air inducing holes which are arranged on the upper side wall of the air inducing pipe section in an array mode, and fan flanges used for installing fans are arranged at the air inducing holes.

Further, the outer cavity comprises an outer cover body and a supporting plate, and the ventilation channel is arranged on the supporting plate.

Has the advantages that: the ventilation channel is arranged on the supporting plate of the outer cavity, so that the cooling airflow has the largest stroke as possible in the microwave plasma chemical vapor deposition device, and a better and more thorough cooling effect is realized.

Furthermore, the bottom of the outer cover body and the bottom of the reaction chamber form an annular interval, the area between the inner cover body and the outer cover body is an annular area surrounding the reaction chamber, and the ventilation channel consists of a plurality of ventilation holes arranged on the annular area of the support plate.

Has the advantages that: the ventilation holes are arranged on the annular area surrounding the reaction chamber on the supporting plate, so that the ventilation channel is arranged around the reaction chamber, and the reaction chamber can be uniformly cooled along the circumferential direction of the reaction chamber when air flow is discharged from the ventilation channel or enters the outer cavity.

Further, be equipped with the wind pressure switch in the induced draft pipe section, microwave plasma chemical vapor deposition device still includes the controller for control microwave generator works, the controller with wind pressure switch signal connection to control microwave generator and shut down when the wind pressure switch detects the wind pressure and reduces to the setting value.

Has the advantages that: when the fan fails and cooling airflow cannot be formed in the microwave plasma chemical vapor deposition device, the wind pressure switch arranged in the wind induction pipe section can monitor the change of wind pressure in the wind induction pipe section and transmit the monitoring result to the controller, and the controller controls the microwave generator to stop according to the monitoring result of the wind pressure switch, so that the phenomenon that the microwave plasma chemical vapor deposition device continues to work when the fan cannot provide cooling airflow and the temperature of core components in the device is overhigh is avoided.

In order to achieve the above purpose, the technical solution of the microwave plasma chemical vapor deposition apparatus of the present invention is as follows:

a microwave plasma chemical vapor deposition apparatus, comprising: the microwave plasma chemical vapor deposition device comprises a microwave generator, a mode converter, an outer cavity and a reaction chamber, wherein the outer cavity and the reaction chamber form a resonant cavity, the microwave plasma chemical vapor deposition device also comprises a communicating waveguide structure which is arranged between the mode converter and the microwave generator and is used for conducting microwaves, the outer cavity is butted with the mode converter, the reaction chamber is positioned in the outer cavity, the communicating waveguide structure comprises an induced air pipe section and an isolation section which are sequentially connected in series in a split mode, the isolation section is positioned on one side of the induced air pipe section, which faces the microwave generator, an induced air channel used for communicating the inner cavity of the induced air pipe section with the outside is arranged on the induced air pipe section, a wave-transmitting wind shield is arranged on the isolation section, a ventilation channel used for communicating the resonant cavity with the outside is arranged on the outer cavity, the ventilation channel is communicated with the induced air channel through the resonant cavity and the mode converter, the microwave plasma, or the air is sucked from the inner cavity of the induced air pipe section, when the fan supplies air to the inner cavity of the induced air pipe section at the induced air channel, the ventilation channel is used for discharging air so as to form cooling air flow between the induced air channel and the ventilation channel, or when the fan sucks air from the inner cavity of the induced air pipe section at the induced air channel, the ventilation channel is used for supplying air so as to form cooling air flow between the induced air channel and the ventilation channel.

The beneficial effects of the utility model reside in that: the communicating waveguide structure arranged between the microwave generator and the mode converter and used for conducting microwave comprises an induced draft pipe section and an isolation section, wherein, an induced air channel is arranged on the induced air pipe section, a fan is butt jointed on the induced air channel, a ventilation channel communicated with the induced air channel is correspondingly arranged on the outer cavity, when the fan works, outside cold air is blown into the inner cavity of the induced draft pipe section to form cooling air flow, the cooling air flow flows to core components such as the mode converter, the plasma deposition chamber, the outer cavity and the like through the inner cavity of the induced draft pipe section, and flows out of the ventilation channel to cool the microwave plasma chemical vapor deposition device, and the isolation section with the wave-transparent wind shield ensures that the cooling air flow cannot flow to the microwave generator on the premise of not blocking the microwave, thereby avoiding the pollution of the microwave generator caused by the dust mixed in the cooling air flow. Similarly, if the fan induced drafts from the waveguide body inner chamber, atmospheric pressure in the microwave plasma chemical vapor deposition device is less than external atmospheric pressure, and external cold air can follow the ventilation passageway and get into in the outer cavity to flow out from the induced air passageway, cool off the core component in the microwave plasma chemical vapor deposition device, ensure that microwave plasma chemical vapor deposition device normally works steadily.

Has the advantages that: the ventilation channel is arranged on the supporting plate of the outer cavity, so that the cold air flow has a stroke as large as possible in the microwave plasma chemical vapor deposition device, and a better and more efficient cooling effect is realized.

Further, the bottom of the outer cover body and the bottom of the reaction chamber form an annular space, the area between the inner cover body and the outer cover body is an annular area surrounding the reaction chamber, and the air inducing channel is formed by a plurality of ventilation holes arranged on the annular area of the support plate.

Has the advantages that: the air guide holes are arranged in an annular area which surrounds the vapor deposition device on the supporting plate, so that the ventilation channel is arranged around the vapor deposition device, and airflow can uniformly cool the vapor deposition device in the circumferential direction when the airflow is discharged from the ventilation channel or enters the outer cavity.

Furthermore, the reaction chamber is enclosed by a support plate and an inner cover body which is hermetically assembled on the support plate, and a lining plate is arranged on the inner side of the support plate facing the inner cover body.

Has the advantages that: the reaction chamber is formed by an inner cover body which is hermetically assembled on the supporting plate, and the ventilation channel is opened on the supporting plate and arranged around the reaction chamber, so that cold air flow passes through the inner cover body on a flow path and the inner cover body is uniformly cooled along the circumferential direction of the inner cover body.

Furthermore, the isolation section comprises an outer flange frame, the wave-transparent wind shield is installed in the outer flange frame, and the outer flange frame is provided with installation holes which are sequentially arranged along the circumferential direction so as to connect the isolation section in series in the communicated waveguide structure.

Has the advantages that: the wave-transparent wind shield is installed in the outer flange frame, then the installation of the wave-transparent wind shield on the microwave plasma chemical vapor deposition device is realized through the outer flange frame on the microwave plasma chemical vapor deposition device, the installation structure does not need to be arranged on the wave-transparent wind shield, and meanwhile, the outer flange frame can also strengthen the protection of the wave-transparent wind shield and prevent the leakage of microwaves from the isolation section.

Further, the wave-transparent wind shield is made of polytetrafluoroethylene.

Has the advantages that: the polytetrafluoroethylene has excellent microwave penetration rate and low cost.

Furthermore, the induced draft pipe section comprises a middle rectangular waveguide pipe and flange end plates at two ends, the flange end plates are fixedly connected with the corresponding ends of the rectangular waveguide pipe in a welding mode, and flange mounting holes which are sequentially arranged along the circumferential direction are formed in the flange end plates so as to connect the induced draft pipe section in the communicated waveguide structure in series.

Has the advantages that: the flange end plates with the flange mounting holes are arranged at the two ends of the induced draft pipe section, so that the induced draft pipe section can be conveniently connected in series in the communicated waveguide structure.

Furthermore, the induced draft pipe section is of a rectangular structure, the upper wall surface and the lower wall surface of the induced draft pipe section are broadside wall surfaces, the left wall surface and the right wall surface are narrow side wall surfaces, and the induced draft channel is arranged on the broadside wall surfaces of the induced draft pipe section.

Has the advantages that: the draught pipe section is arranged to be of a broadside wall surface structure, the draught channel is arranged on the broadside wall surface, a base body as large as possible is provided for the setting of the draught channel, the setting of the draught channel is facilitated, and the draught channel can be provided with a large opening.

Furthermore, the upper wall surface of the air inducing pipe section is provided with air inducing holes which are arranged in an array mode, the air inducing holes form an air inducing channel, and a fan flange used for installing a fan is arranged at the air inducing holes.

Has the advantages that: the structure of the induced air channel is simplified by directly arranging the induced air hole on the side wall of the waveguide body, so that the structure of the waveguide assembly is simplified.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment 1 of a microwave plasma CVD apparatus according to the present invention;

FIG. 2 is a schematic structural diagram of a support plate of the microwave plasma CVD apparatus according to the present invention;

FIG. 3 is a schematic structural view of an induced draft tube section of embodiment 1 of the microwave plasma CVD apparatus according to the present invention;

FIG. 4 is a schematic structural view of an upper waveguide plate according to embodiment 1 of the present invention;

FIG. 5 is a schematic structural view of a microwave plasma CVD apparatus according to embodiment 1 of the present invention, in a state where a groove cover plate is not installed on a left waveguide plate;

FIG. 6 is a schematic structural view of a microwave plasma CVD apparatus according to embodiment 1 of the present invention in a state where a groove cover plate is mounted on a left waveguide plate;

FIG. 7 is a schematic view of the arrangement of the wave-transparent wind shield in the wind-guiding pipe section according to embodiment 1 of the microwave plasma CVD apparatus of the present invention;

FIG. 8 is a schematic structural diagram of an embodiment 4 of a microwave plasma CVD apparatus according to the present invention;

FIG. 9 is a schematic structural view of an induced draft duct section of embodiment 4 of a microwave plasma CVD apparatus according to the present invention;

FIG. 10 is a schematic structural view of an isolation section of embodiment 4 of a microwave plasma CVD apparatus according to the present invention;

in the figure: 11. a microwave generator; 12. a circulator; 13. a three-pin adapter; 2. a mode converter; 21. a conical member; 22. a coaxial antenna; 3. a resonant cavity; 4. an outer cover body; 5. a support plate; 51. a vent hole; 52. a sealing groove; 53. a substrate tank; 6. a waveguide assembly; 61. an induced draft tube section; 1611. an upper waveguide plate; 6111. the bolt passes through the hole; 6112. a wind-guiding hole; 6113. a fan flange; 6114. an upper waveguide plate body; 6115. a rectangular boss; 1612. a left waveguide plate; 6121. a slot cover plate; 6122. a coolant inlet; 6123. a coolant outlet; 6124. a cooling liquid tank; 1613. a lower waveguide plate; 1614. a right waveguide plate; 62. a fan; 63. a wave-transparent wind shield; 7. a reaction chamber; 71. an inner cover body; 72. plasma; 73. a substrate; 8. a sliding piston; 9. communicating the waveguide structures; 91. an induced draft tube section; 92. an isolation section; 2611-upper wall surface; 2612-induced air holes; 2613-fan flange; 2614-wind pressure switch fixing holes; 621-outer flange frame; 622-wave-transparent wind deflector.

Detailed Description

When the microwave plasma chemical vapor deposition device works, the microwave plasma chemical vapor deposition device can be divided into a low-power microwave plasma chemical vapor deposition device and a high-power microwave plasma chemical vapor deposition device according to the power of the microwave plasma chemical vapor deposition device, wherein the low-power microwave plasma chemical vapor deposition device is used for 6-8kW of power, and the high-power microwave plasma chemical vapor deposition device is used for 60-100kW of power. The utility model discloses the microwave plasma chemical vapor deposition device of well waveguide subassembly mainly used high power to solve the microwave plasma chemical vapor deposition device of high power and easily produce the problem of high temperature at its core component of during operation, of course, if low-power microwave plasma chemical vapor deposition device also need cool off its inside core component under certain operating mode, the utility model provides a waveguide subassembly still can be used to low-power microwave plasma chemical vapor deposition device. The microwave plasma chemical vapor deposition apparatus provided with the waveguide assembly of the present invention will be described first.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 1, as shown in fig. 1-7, microwave plasma chemical vapor deposition device mainly includes microwave generator 11, circulator 12, three pin tuner 13, mode converter 2, sliding piston 8, encloses into resonant cavity 3 the outer cavity, is located resonant cavity 3's reacting chamber 7, outer cavity and the butt joint of mode converter 2. And further includes a communicating waveguide structure disposed between the mode converter 2 and the microwave generator 11 to guide microwaves.

The mode converter 2 includes a cone 21 and a coaxial antenna 22, the mode converter 2 is used for converting the mode of the microwave, and the working principle thereof belongs to the prior art, for example, a microwave plasma chemical vapor deposition apparatus disclosed in chinese patent publication No. CN104726850B, the microwave mode converter in the apparatus can convert the microwave in the TE mode into the microwave in the TEM mode when in operation, and therefore, the structure and the working principle of the mode converter 2 in the present application are not described herein again.

The outer cavity comprises an outer cover body 4 and a support plate 5, the outer cover body 4 is covered on the support plate 5, the reaction chamber 7 is enclosed by an inner cover body 71 which is hermetically assembled on the support plate 5, wherein the support plate 5 is used for bearing the inner cover body 71 and a corresponding substrate, and the support plate 5 can slide up and down relative to the outer cover body 4 to adjust the height of the support plate. In other embodiments, the support plate may not slide relative to the outer cover without adjustment of the support plate height.

The structure of the supporting plate 5 is as shown in fig. 2, a sealing groove 52 is arranged on the supporting plate 5, and an inner cover 71 is installed in the sealing groove 52, so that the inner cover 71 is hermetically assembled on the supporting plate 5. The inner side of the support plate 5 facing the inner cover 71 is provided with a substrate groove 53 for placing a substrate 73, and a plasma 72 is placed on the substrate 73. In this embodiment, the inner cover 71 is a quartz bell jar, and in other embodiments, the inner cover may be made of polytetrafluoroethylene or sapphire with high microwave transmittance.

The lower part of the outer cover body 4 and the lower part of the reaction chamber 7 form an annular space, correspondingly, the area of the support plate 5 between the inner cover body 71 and the outer cover body 4 is an annular area surrounding the reaction chamber 7, a plurality of vent holes 51 are arranged on the annular area, the vent holes 51 form a vent channel, and the vent channel communicates the resonant cavity 3 with the outside. In other embodiments, to facilitate manufacturing, the ventilation hole may also be a circular hole with an aperture meeting ventilation requirements, which is disposed on the supporting plate. Of course, the ventilation channel can also be provided on the outer cover.

During specific work, microwaves generated in the microwave generator 11 enter the resonant cavity 3 after passing through the circulator 12, the three-pin tuner 13, the communication waveguide structure, the mode converter 2 and the sliding piston 8, the microwaves are gathered at the substrate 73 of the quartz bell jar, low-pressure gas in the quartz bell jar is ionized to form plasma, and a diamond film is deposited on the substrate 73. As to the dispenser options, in other embodiments, other models of dispensers may be used, such as a three E-T dispenser, a dual T dispenser, and so forth. The dispenser and circulator can also be omitted.

In order to avoid the overhigh temperature of relevant parts inside the microwave plasma chemical vapor deposition device during operation, one section of the communicated waveguide structure is a waveguide assembly 6 which can introduce external cold air into the device, the waveguide assembly 6 comprises an induced draft pipe section 61, the induced draft pipe section 61 is arranged between the microwave generator 11 and the mode converter 2 to conduct microwaves, an induced draft channel is arranged on the induced draft pipe section 61, and the induced draft channel is communicated with the ventilation channel through the waveguide assembly 6, the mode converter 2 and the resonant cavity 3. And through the air inlet and outlet of the air flow at the air inducing channel and the ventilation channel, the external cooling air flow is introduced into the device to form cooling air flow flowing through the mode converter 2, the reaction chamber 7 and the like in the device, so that the device is cooled.

Specifically, the draught passage is butted with a fan 62, in this embodiment, when the fan 62 works, a positive pressure is formed at the draught passage to send outside cold air into the waveguide assembly 6, a cooling air flow is formed in the inner cavity of the draught pipe section 61, and the cooling air flow flows through the mode converter 2, the reaction chamber 7 and other components and then flows out of the ventilation passage formed in the outer cavity to the outside.

The concrete structure of the draft tube section 61 of the waveguide assembly 6 is as shown in fig. 3, the draft tube section 61 is a rectangular tube structure, and includes an upper waveguide plate 1611, a left waveguide plate 1612, a lower waveguide plate 1613 and a right waveguide plate 1614, the upper waveguide plate 1611 forms an upper wall surface of the draft tube section, and the draft channel is disposed on the upper waveguide plate 1611. In this embodiment, the air inducing channel is formed by the air inducing holes 6112 arranged in an array on the upper waveguide plate 1611, and the aperture of the air inducing holes 6112 is such that the microwave does not leak from the air inducing holes 6112. In order to facilitate the installation of the fan 62, a fan flange 6113 is arranged at the air inducing channel, and when the fan 62 is installed, the fan 62 is directly butted on the fan flange 6113.

In other embodiments, the air inducing channel may also be disposed on other side walls of the air inducing pipe segment, and of course, the air inducing pipe segment may also be a structure with more than four cross-sectional edges, for example, the cross section of the air inducing pipe segment is hexagonal, octagonal, or the like, or the air inducing pipe segment may be a pipe with less than four cross-sectional edges, for example, the cross section of the air inducing pipe segment is triangular. Of course, the air induction pipe section can also be of a circular tubular structure.

Further, the draft tube section 61 is provided as a separate structure, and the upper waveguide plate 1611, the lower waveguide plate 1613, the left waveguide plate 1612 and the right waveguide plate 1614 are relatively independent in structure.

The waveguide assembly 6 is further provided with a liquid cooling system, specifically, the liquid cooling system includes cooling liquid tanks respectively disposed on the left waveguide plate 1612, the lower waveguide plate 1613, and the right waveguide plate 1614, each cooling liquid tank is hermetically mounted with a tank cover plate 6121, and the tank cover plate 6121 is provided with a cooling liquid inlet 6122 and a cooling liquid outlet 6123. In this embodiment, as shown in fig. 5, the cooling liquid tank 6124 has a U-shaped structure, and correspondingly, the tank cover plate 6121 also has a U-shaped structure, wherein the cooling liquid inlet 6122 and the cooling liquid outlet 6123 are respectively disposed on two branches of the tank cover plate 6121.

The liquid cooling system is arranged, so that the induced draft pipe section 61 can be cooled, the outside air entering the inner cavity of the induced draft pipe section 61 is cooled, and the cooling efficiency of cooling airflow to core components in the device is improved. Meanwhile, the induced draft pipe section 61 with relatively low temperature can also cool the device directly contacted and connected with the induced draft pipe section through heat conduction.

In other embodiments, the structure of the liquid cooling system may also be a structure of a water cooling system used in a microwave breach device of a high-temperature cavity disclosed in the chinese utility model patent with the publication number CN208590129U, specifically, an annular cavity is disposed outside the induced draft pipe section, and a cooling water inlet and a cooling water outlet are disposed on the cavity. Of course, under the condition that the external air can meet the cooling requirement of the device, the liquid cooling system is not required to be arranged on the induced draft pipe section.

The upper waveguide plate 1611 is structured as shown in fig. 4, the upper waveguide plate 1611 includes an upper waveguide plate body 6114, rectangular bosses 6115 are provided at front and rear ends of an upper surface of the upper waveguide plate body 6114, left and right ends of the rectangular bosses 6115 are flush with left and right end surfaces corresponding to the upper waveguide plate body 6114, a front end surface of the rectangular boss 6115 located at a front end of the upper waveguide plate body 6114 is flush with a front end surface of the upper waveguide plate body 6114, and a rear end surface of the rectangular boss 6115 located at a rear end of the upper waveguide plate body 6114 is flush with a rear end surface of the upper waveguide plate body 6114. Threaded holes are formed in the left side surface and the right side surface of the upper waveguide plate body 6114 and the rectangular boss 6115. The structure of the lower waveguide plate 1613 is different from that of the upper waveguide plate 1611 only in that the upper waveguide plate body 6114 is provided with a wind inducing hole 6112, and the lower waveguide plate body is provided with a liquid cooling system.

The structure of the left waveguide plate 1612 is as shown in fig. 5, the left waveguide plate 1612 includes a left waveguide plate body, cross beams are arranged at two ends of the left waveguide plate body, the upper and lower ends of the cross beams are suspended relative to the upper and lower sides of the left waveguide plate body, and the suspended length is equal to the thickness of a rectangular boss 6115 on the upper waveguide plate body. The left waveguide plate 612 is provided with counter bores corresponding to the threaded holes of the upper waveguide plate 1611 and the lower waveguide plate 1613. The structure of the right waveguide plate 1614 is the same as that of the left waveguide plate 1613, so that the left waveguide plate 1612 and the right waveguide plate 1614 may be interchanged. When assembled, the upper waveguide plate 1611, the lower waveguide plate 1613, the left waveguide plate 1612, and the right waveguide plate 1614 are assembled together by bolts screwed into threaded holes.

After the assembly is completed, the rectangular bosses at the front ends of the upper waveguide plate and the lower waveguide plate are correspondingly connected with the cross beams at the front ends of the left waveguide plate and the right waveguide plate to form a front frame of the induced draft pipe section 61, the rectangular bosses at the rear ends of the upper waveguide plate and the lower waveguide plate are correspondingly connected with the cross beams at the rear ends of the left waveguide plate and the right waveguide plate to form a rear frame of the induced draft pipe section 61, and mounting holes for mounting the induced draft pipe section 61 on the device are formed in the front frame and the rear frame of the induced draft pipe section 61. In other embodiments, the inducer section may be provided as a unitary structure.

In order to prevent dust particles in the air from entering core components such as the three-pin tuner 13, the circulator 12 and the microwave generator 11, a wave-transparent wind shield 63 is further arranged in the waveguide assembly 6, the wave-transparent wind shield 63 is a polytetrafluoroethylene plate with high microwave penetration rate, and the arrangement of the wave-transparent wind shield 63 can seal an inner cavity of the air-guiding pipe section 61 on the premise of not influencing the passing of microwaves, so that cooling air flow is ensured not to flow to the core components such as the three-pin tuner 13, the circulator 12 and the microwave generator 11. In other embodiments, the material of the wave-transparent wind shield can also be quartz or sapphire with high microwave transmittance.

The concrete structure of the wave-transparent wind shield 63 and the arrangement mode of the wave-transparent wind shield in the air induction pipe section 61 are shown in fig. 7, the wave-transparent wind shield 63 is a plate-shaped structure with a parallelogram cross section, wave-transparent wind shield mounting holes are arranged on the upper, lower, left and right side surfaces of the wave-transparent wind shield, correspondingly, bolt through holes 6111 corresponding to the wave-transparent wind shield mounting holes are arranged on the upper, lower, left and right waveguide plates of the air induction pipe section 61, the bolt through holes 6111 are of a counter bore structure, and the wave-transparent wind shield 63 can be fixed in the inner cavity of the air induction pipe section 61 by screwing bolts in the wind shield mounting. In order to make the structure of the whole waveguide assembly 6 more compact, the bolt through holes 6111 on the left and right waveguide plates are opened in the middle of the U-shaped structure of the cooling liquid tank, so that the middle space of the U-shaped cooling liquid tank is utilized.

The wave-transparent wind shield 63 is obliquely arranged in the induced draft pipe section 61, the induced draft pipe section 61 has a length extending direction corresponding to the microwave transmission direction, the wave-transparent wind shield 63 is obliquely arranged, the wave-transparent wind shield 63 corresponds to the induced draft channel in the length extending direction of the induced draft pipe section 61, the wave-transparent wind shield 63 is obliquely arranged at an angle of 40-45 degrees, and the obliquely arranged wave-transparent wind shield 63 is used for guiding cooling air flow blown into the inner cavity of the induced draft pipe section 7. For the inclination angle of the wave-transparent wind shield, in other embodiments, the angle may be smaller than 40 ° or larger than 45 ° according to actual working conditions, and of course, the wave-transparent wind shield may be vertically disposed in the wind-inducing pipe section.

The utility model provides a microwave plasma chemical vapor deposition device is at the during operation, fan 62 forms the malleation in induced air passageway department and sends into induced air pipeline section 61 inner chamber with external cold air, form cooling air flow in induced air pipeline section 61's inner chamber, cooling air flow direction ventilation passageway on the way, can pass through mode converter 2, resonant cavity 3 and be located the reaction chamber 7 class core component in resonant cavity 3, cool down to the core component, ensure that microwave plasma chemical vapor deposition device can not appear the too high phenomenon of core component temperature at the during operation, thereby ensure that microwave plasma chemical vapor deposition device has stable working property.

Further, in order to avoid the overhigh temperature of each part caused by the failure of the fan 62 in the operation process of the microwave plasma chemical vapor deposition device, a wind pressure switch is arranged in the wind induction pipe section 61 and used for detecting the wind pressure in the wind induction pipe section 61 in the operation process of the microwave plasma chemical vapor deposition device so as to judge whether the fan 62 fails or not, correspondingly, the microwave plasma chemical vapor deposition device further comprises a controller, and the controller can receive a signal sent by the wind pressure switch and control the start and stop of the microwave generator 11 according to the signal.

If the fan 62 stops working due to a fault, the wind pressure in the induced draft tube section 61 is lower than a set value of the wind pressure switch, the wind pressure switch can send a signal to the P L C controller, and the P L C controller controls the microwave generator 11 to stop working according to the signal sent by the wind pressure switch, so that the phenomenon that the temperature of components such as a mode converter, a resonant cavity, a quartz bell jar and the like is too high due to the stop working of the fan 62 in the operation process of the microwave plasma chemical vapor deposition device is avoided, and the stability and the safety of the operation of equipment are ensured.

For the arrangement mode of the wind pressure switch, in order to ensure the sealing performance of the induced draft pipe section, a wind pressure switch fixing hole is not formed on the upper wall surface of the induced draft pipe section, but an installation groove for placing the wind pressure switch is formed in the inner wall of the induced draft pipe section. The controller may also be a single chip controller. Of course, if the working state of the fan can be directly judged to be normal through external observation, the wind pressure switch and the corresponding control system are not needed.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 2, this embodiment only lies in with embodiment 1's difference, the fan in embodiment 1 forms the malleation in induced air passageway department and supplies air to induced air pipe section inner chamber, and the fan in this embodiment forms the negative pressure at induced air passageway department and induced drafts from induced air pipe section inner chamber, in order to form the negative pressure in the device, make the outside air can follow and get into the resonant cavity in the ventilation passageway, and flow through parts such as reacting chamber, mode converter and waveguide assembly, and discharge from the induced air passageway.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 3, this embodiment only lie in with embodiment 1's difference, and the induced air passageway in embodiment 1 comprises the induced air hole of seting up the array arrangement on the lateral wall on the induced air pipeline section, and in this embodiment, the induced air passageway sets up the branch pipeline for setting up on the lateral wall of induced air pipeline section, sets up the shielding net in the pipeline and prevents that the microwave from leaking, and the fan docks with the branch pipeline.

The utility model discloses well waveguide assembly's embodiment: the utility model provides a waveguide assembly that relates to includes the induced air pipeline section, fan and wave-transparent deep bead, wherein, the induced air pipeline section is arranged between microwave generator and mode converter with the conduction microwave, the extension sets up on the induced air pipeline section, the fan can form the air current in the induced air pipeline section at the during operation, thereby not cooling the core in the microwave plasma chemical vapor deposition device that uses this waveguide assembly, concrete structure and the working method about this waveguide assembly are the same with the structure of the waveguide assembly in above-mentioned microwave plasma chemical vapor deposition device, no longer give unnecessary details here.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 4, the difference with embodiment 1 is that, in embodiment 1, arrange between mode converter 2 and microwave generator 11 with one of them section of the intercommunication waveguide structure of conduction microwave be waveguide assembly 6, waveguide assembly 6 can be with in the external cold air introducing device.

The microwave plasma chemical vapor deposition apparatus in this embodiment is different from that in embodiment 1 only in that, as shown in fig. 8, a communicating waveguide structure 9 for conducting microwaves is disposed between the mode converter 2 and the microwave generator 11, the communicating waveguide structure 9 includes an induced air pipe section 91 capable of introducing external cold air into the apparatus, an induced air channel is disposed on the induced air pipe section 91, and the induced air channel is communicated with the ventilation channel through the induced air pipe section 91, the mode converter 2, and the resonant cavity 3. Through the air flow inlet and outlet of the air inducing channel and the ventilation channel, outside cold air is introduced into the device to form cooling air flow flowing through the mode converter 2, the reaction chamber 7 and the like in the device, so that the device is cooled.

Specifically, the air inducing channel is connected with the fan 63 in a butt joint mode, when the fan 63 works, positive pressure is formed at the air inducing channel, outside cold air is sent into the air inducing pipe section 91, cooling air flow is formed in an inner cavity of the air inducing pipe section 91, and the cooling air flow flows through the mode converter 2, the reaction chamber 7 and other components and then flows out of a ventilation channel formed in the outer cavity to the outside.

The concrete structure of the induced draft pipe section 91 is as shown in fig. 9, the induced draft pipe section 91 includes a middle rectangular waveguide tube, flange end plates are fixed at the front and rear ends of the induced draft pipe section 91, the flange end plates are welded and fixed on the rectangular waveguide tube, and flange mounting holes sequentially arranged along the circumferential direction are formed in the flange end plates and used for serially connecting the induced draft pipe section 91 in the communicated waveguide structure 9. In this embodiment, the widths of the upper wall surface 2611 and the lower wall surface of the duct guiding section 91 are larger than the widths of the left wall surface and the right wall surface. The air inducing channel is arranged on the upper wall surface 2611 of the air inducing pipe section 91.

In other embodiments, for the arrangement position of the induced air channel, the induced air channel can also be arranged on other side walls of the induced air pipe section. For the structure of the induced draft pipe section, the number of section edges can be more than four, for example, the cross section of the induced draft pipe section is hexagonal, octagonal and the like, or the induced draft pipe section can be set to be a pipe with the cross section edges less than four, for example, the cross section of the induced draft pipe section is triangular. Of course, the induced draft tube section can also be a circular tube. The front end and the rear end of the induced draft pipe section are also not provided with induced draft pipe section mounting flanges, and at the moment, the induced draft pipe section is connected with corresponding parts in a plug-in mounting mode.

Regarding the specific structure of the air inducing channel, in this embodiment, the air inducing channel is formed by the air inducing holes 2612 arranged in an array on the upper wall surface 2611, and the aperture of the air inducing holes 2612 is such that the microwave does not leak from the air inducing holes 2612. In order to facilitate the installation of the fan 62, the fan flange 2613 is arranged at the induced air channel, and when the fan 62 is installed, the fan 62 is directly butted and installed on the fan flange 2613.

In order to prevent dust particles in the outside air entering the induced draft tube section from entering the core components such as the three-pin tuner 13, the circulator 12 and the microwave generator 11, the communicating waveguide structure 9 further comprises an isolation section 92 which is connected with the induced draft tube section 91 in series in a split manner, and the isolation section 92 is arranged on one side of the induced draft tube section 91 facing the microwave generator 11.

Specifically, as shown in fig. 10, the isolation section 92 includes an outer flange frame 621 and a wave-transparent wind shield 622 embedded in the outer flange frame 621, and the wave-transparent wind shield 622 is a teflon plate with high microwave transmittance, so as to ensure that microwaves can pass through the isolation section 92. The outer flange frame 621 is configured and dimensioned to match the configuration and dimensions of the flange end plates at the ends of the draft tube sections. In order to mount the isolation section 92 on the microwave plasma chemical vapor deposition apparatus, the outer flange frame 621 is provided with mounting holes sequentially arranged along the circumferential direction, so as to connect the isolation section 92 in series in the communicating waveguide structure 9. The arrangement of the isolation section 92 realizes the plugging of one end of the communication waveguide structure 9 facing the microwave generator 11 on the premise of not influencing the passing of the microwave, and ensures that the cooling airflow in the induced draft tube section 91 cannot flow to the core components such as the three-pin tuner 13, the circulator 12 and the microwave generator 11. For the material of the wave-transparent wind shield, quartz or sapphire can be selected in other embodiments.

In this embodiment, the structure for installing the wind pressure switch is a wind pressure switch fixing hole 2614, and the wind pressure switch fixing hole 2614 is formed on the upper wall surface 2611 of the induced draft tube section. For the setting mode of the wind pressure switch, other installation modes described in embodiment 1 may also be adopted, and similarly, if the working state of the fan can be directly judged to be normal through external observation, the wind pressure switch and the corresponding control system may not be provided.

The utility model provides a microwave plasma chemical vapor deposition device is at the during operation, fan 62 forms the malleation at induced air passageway department and sends into induced air pipeline section 91 inner chamber with external cold air, form cooling air flow in induced air pipeline section 91's inner chamber, cooling air flow direction ventilation passageway on the way, can pass through mode converter 2, resonant cavity 3 and be located the reacting chamber 7 class core component in resonant cavity 3, cool down to the core component, ensure that microwave plasma chemical vapor deposition device can not appear the too high phenomenon of core component temperature at the during operation, thereby ensure that microwave plasma chemical vapor deposition device has stable working property.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 5, this embodiment only lies in with embodiment 4's difference, the fan in embodiment 4 forms the malleation at induced air passageway department and supplies air in to induced air pipe section inner chamber, and the fan in this embodiment forms the negative pressure at induced air passageway department and induced drafts from induced air pipe section inner chamber, in order to form the negative pressure in the device, make the outside air can follow and get into the resonant cavity in the ventilation passageway, and flow through parts such as reacting chamber, mode converter and waveguide assembly, and discharge from the induced air passageway.

The utility model discloses well microwave plasma chemical vapor deposition device's embodiment 6, this embodiment only lie in with embodiment 4's difference, and the induced air passageway in embodiment 4 comprises the induced air hole of seting up the array arrangement on induced air pipeline section lateral wall, and in this embodiment, the induced air passageway sets up the branch pipeline for setting up on the lateral wall of waveguide body, sets up the shielding net in the pipeline and prevents that the microwave from leaking, and the fan docks with the branch pipeline.

Claims

1. A waveguide component is characterized by comprising an induced draft pipe section, a fan and a wave-transparent wind shield,

the induced draft tube section is arranged between the microwave generator and the mode converter to conduct microwaves,

the side wall of the induced draft pipe section is provided with an induced draft channel for communicating the inner cavity of the induced draft pipe section with the outside,

the fan is butted with the induced air channel and used for supplying air to the inner cavity of the induced air pipe section at the induced air channel or sucking air from the inner cavity of the induced air pipe section so as to form cooling airflow in the inner cavity of the induced air pipe section,

and a wave-transmitting wind shield is fixedly arranged in the induced draft pipe section and used for blocking airflow from flowing to the microwave generator.

2. The waveguide assembly of claim 1, wherein the plurality of air-guiding channels are an array of air-guiding holes, and wherein the air-guiding holes are provided with fan flanges for mounting the fan.

3. The waveguide assembly of claim 1 or 2, wherein the fan supplies air into the duct section at the draught aperture, and a liquid cooling system is provided on the duct section to cool the duct section.

4. The waveguide assembly of claim 3, wherein the induced draft tube section is a split rectangular tube structure including an upper waveguide plate, a lower waveguide plate, a left waveguide plate and a right waveguide plate, the induced draft passage is disposed on the upper waveguide plate, the liquid cooling system includes cooling liquid slots opened on the left waveguide plate, the right waveguide plate and the lower waveguide plate, each cooling liquid slot is hermetically mounted with a slot cover plate, each slot cover plate is provided with a cooling liquid inlet and a cooling liquid outlet.

5. The waveguide assembly of claim 4, wherein the left waveguide plate has a U-shaped cooling liquid slot, the slot cover plate has a U-shaped cover plate adapted to the cooling liquid slot, a bolt hole is formed in the middle of the U-shaped cooling liquid slot for passing a bolt for fixing the wave-transparent wind shield, and the right waveguide plate has the same structure as the left waveguide plate.

6. A microwave plasma chemical vapor deposition device comprises a microwave generator, a mode converter, an outer cavity forming a resonant cavity and a reaction chamber,

further comprising a communicating waveguide structure disposed between the microwave generator and the mode converter to conduct the microwave,

the outer cavity is in butt joint with the mode converter,

the reaction chamber is positioned in the outer cavity and is characterized in that,

the communicating waveguide structure comprising the waveguide assembly of any one of claims 1 to 5,

the outer cavity is provided with a ventilation channel for communicating the resonant cavity with the outside, the ventilation channel is communicated with the induced draft channel in the waveguide component through the resonant cavity, the mode converter and the communicating waveguide structure,

when the fan supplies air to the inner cavity of the induced duct section at the induced duct, the ventilation channel is used for discharging air so as to form cooling airflow between the induced duct and the ventilation channel,

or when the fan sucks air from the inner cavity of the induced air pipe section at the induced air channel, the ventilation channel is used for supplying air so as to form cooling air flow between the induced air channel and the ventilation channel.

7. A microwave plasma chemical vapor deposition apparatus as recited in claim 6, wherein the outer chamber includes an outer casing and a support plate, the ventilation passage being provided in the support plate.

8. A microwave plasma chemical vapor deposition apparatus according to claim 7, wherein the bottom of the outer cover and the bottom of the reaction chamber form an annular space, the area of the support plate between the inner cover and the outer cover is an annular area surrounding the reaction chamber, and the ventilation passage is composed of a plurality of ventilation holes provided in the annular area of the support plate.

9. A microwave plasma CVD apparatus according to claim 6 wherein a wind pressure switch is provided in the draft tube section, and the microwave plasma CVD apparatus further includes a controller for controlling the operation of the microwave generator, the controller being in signal connection with the wind pressure switch to control the microwave generator to be stopped when the wind pressure switch detects that the wind pressure is reduced to a set value.

10. A microwave plasma chemical vapor deposition apparatus, comprising:

a microwave generator, a mode converter, an outer cavity forming a resonant cavity and a reaction chamber,

further comprising a communicating waveguide structure disposed between the mode converter and the microwave generator to conduct microwaves,

the outer cavity is in butt joint with the mode converter,

the reaction chamber is positioned in the outer cavity,

it is characterized in that the utility model is characterized in that,

the communicating waveguide structure comprises an induced draft pipe section and an isolation section which are sequentially connected in a split and serial manner, the isolation section is positioned on one side of the induced draft pipe section facing the microwave generator,

the induced draft pipe section is provided with an induced draft channel for communicating the inner cavity of the induced draft pipe section with the outside, the isolation section is provided with a wave-transparent wind shield,

the outer cavity is provided with a ventilation channel for communicating the resonant cavity with the outside, the ventilation channel is communicated with the induced draft channel through the resonant cavity and the mode converter,

the microwave plasma chemical vapor deposition device also comprises a fan which is butted with the induced air channel and is used for supplying air to the inner cavity of the induced air pipe section at the induced air channel or absorbing air from the inner cavity of the induced air pipe section,

11. A microwave plasma chemical vapor deposition apparatus as recited in claim 10, wherein the outer chamber includes an outer casing and a support plate, the ventilation channel being provided on the support plate.

12. A microwave plasma chemical vapor deposition apparatus as defined in claim 11, wherein the bottom of the outer cover and the bottom of the reaction chamber form an annular space, the area of the support plate between the inner cover and the outer cover is an annular area surrounding the reaction chamber, and the air inducing passage is formed by a plurality of ventilation holes provided on the annular area of the support plate.

13. A microwave plasma chemical vapor deposition apparatus as claimed in claim 11, wherein the reaction chamber is enclosed by a support plate and an inner cover body sealingly fitted over the support plate, the support plate being provided with a liner plate on an inner side thereof facing the inner cover body.

14. A microwave plasma chemical vapor deposition apparatus according to any one of claims 10 to 13, wherein the isolation section comprises an outer flange frame, the wave-transparent wind shield is mounted in the outer flange frame, and the outer flange frame is provided with mounting holes arranged in sequence along a circumferential direction so as to connect the isolation section in series in the communicating waveguide structure.

15. A microwave plasma chemical vapor deposition apparatus as defined in claim 14, wherein the wave-transparent baffle is made of polytetrafluoroethylene.

16. A microwave plasma chemical vapor deposition apparatus as defined in claim 11, wherein the induced draft tube section includes a middle rectangular waveguide tube and flange end plates at both ends, the flange end plates are fixedly connected to the corresponding ends of the rectangular waveguide tube by welding, and the flange end plates are provided with flange mounting holes arranged in sequence along a circumferential direction so as to connect the induced draft tube section in series in the communicating waveguide structure.

17. A microwave plasma chemical vapor deposition apparatus according to claim 10 or 16, wherein the draft tube section has a rectangular structure, the upper wall surface and the lower wall surface of the draft tube section are broad-side wall surfaces, the left wall surface and the right wall surface are narrow-side wall surfaces, and the draft passage is provided on the broad-side wall surface of the draft tube section.

18. A microwave plasma chemical vapor deposition apparatus according to claim 17, wherein the upper wall surface of the air-inducing pipe section is provided with air-inducing holes arranged in an array, the air-inducing holes constitute an air-inducing channel, and a fan flange for mounting a fan is provided at the air-inducing holes.