CN113088938B

CN113088938B - Multi-Microwave Source Plasma Chemical Vapor Deposition Apparatus

Info

Publication number: CN113088938B
Application number: CN202110376021.3A
Authority: CN
Inventors: 杨阳; 朱铧丞
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2021-04-08
Filing date: 2021-04-08
Publication date: 2022-03-11
Anticipated expiration: 2041-04-08
Also published as: CN113088938A

Abstract

The invention discloses a multi-microwave source plasma chemical vapor deposition device, belonging to the technical field of microwave applications, comprising a shielding shell, a quartz enclosure, a base and several microwave sources; a reaction cavity is arranged in the shielding shell; enclosure; the top and bottom of the quartz enclosure extend to the top and bottom of the shielding shell respectively; the quartz enclosure surrounds the base cavity; the top and bottom of the shielding enclosure respectively close the top and bottom of the base cavity; the base cavity is provided with a base The base is used to place the substrate; the shielding shell is provided with feed ports corresponding to the microwave sources one-to-one; the feed ports are used for the corresponding microwave sources to input microwaves into the reaction cavity outside the base body cavity. The multi-microwave source plasma chemical vapor deposition device of the invention has the advantages of high quality diamond film, no impurities, low requirement for microwave source power, low cost, high utilization rate of microwave energy, high electric field intensity, and concentrated electric field intensity distribution. The isolation between the microwave input ports is high.

Description

Plasma chemical vapor deposition device with multiple microwave sources

Technical Field

The invention belongs to the technical field of microwave application, and particularly relates to a multi-microwave source plasma chemical vapor deposition device.

Background

Microwave plasma chemical vapor deposition, abbreviated as MPCVD. The reaction principle is as follows: the microwave source emits microwave with specific frequency, the microwave is transmitted along the waveguide, is adjusted by the three screws and the short circuit piston or is coupled into the resonant cavity by the mode conversion antenna, enters the reaction cavity through the quartz medium window, and is focused to form a strong electric field area above the substrate, the strong electric field excites ionized reaction gas to form plasma, and finally deposition of the diamond film is realized.

The existing MPCVD device has low microwave energy utilization rate due to microwave loss because microwave transmission is coupled into a resonant cavity through a mode conversion antenna. And due to the structural limitation of the existing MPCVD device, the adopted microwave sources are single microwave sources, the requirement on the power of the microwave sources is high, the device is complex and the cost is high. The diamond film manufactured by the existing MPCVD device has low quality because the existing structure has quartz glass above the substrate, which causes the diamond film to be mixed with impurities.

Disclosure of Invention

The invention aims to provide a multi-microwave source plasma chemical vapor deposition device aiming at the defects, and solves the problems of low microwave energy utilization rate, high requirement on microwave source power, complex device, high cost, low quality of the manufactured diamond film and the like of the existing MPCVD device. In order to achieve the purpose, the invention provides the following technical scheme:

the multi-microwave source plasma chemical vapor deposition device comprises a shielding shell 1, a quartz enclosure 2, a base station 3 and a plurality of microwave sources; a reaction cavity is arranged in the shielding shell 1; a quartz enclosure 2 is arranged in the reaction cavity; the top and the bottom of the quartz enclosure 2 extend to the top plate and the bottom plate of the shielding shell 1 respectively; the quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; a base station 3 is arranged in the base chamber 4; the base table 3 is used for placing a base body 14; the shielding shell 1 is provided with feed ports 5 which correspond to the microwave sources one by one; the feed openings 5 are used for the corresponding microwave sources to input microwaves into the reaction chamber outside the substrate chamber 4. According to the structure, a plurality of microwave sources input microwaves into the reaction cavity outside the matrix cavity 4 through the corresponding feed ports 5, then the microwaves penetrate through the quartz enclosure 2 to form a strong electric field on the base platform 3, and the strong electric field excites and ionizes reaction gases to form plasma, so that the deposition of a diamond film is realized. According to the multi-microwave-source plasma chemical vapor deposition device, the microwave source is adopted to feed microwaves into the reaction cavity directly, the mode conversion antenna is omitted, energy loss through the mode conversion antenna is avoided, and the utilization rate of the microwave energy is improved; the microwave source injection device has a simple structure, is easy to process, can adopt a plurality of microwave sources to inject microwaves into the reaction cavity together, and can reduce the power requirement on a single feed source, thereby reducing the cost, and the cost price of the microwave source is greatly reduced due to the reduction of the power of the microwave source. The quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; the substrate cavity 4 forms a closed space, and the quartz enclosure 2 only encloses the substrate cavity 4, so that quartz glass is not arranged above the substrate 14 on the base station 3 in the substrate cavity 4, the diamond film is not mixed with impurities, and the quality of the manufactured diamond film is high.

Further, a top plate of the shielding shell 1 is provided with an upward convex cover body 6; an adjusting cavity 7 is arranged in the cover body 6; the adjusting cavity 7 is positioned right above the base station 3; the bottom of the adjusting cavity 7 is communicated with the basal body cavity 4. With the above structure, the adjustment chamber 7 increases the space right above the base 3, so that the electric field is distributed as required, and a strong electric field area is focused above the substrate 14.

Furthermore, a plurality of microwave sources and corresponding feed ports 5 are arranged on the top plate of the shielding shell 1 and uniformly surround the quartz enclosure 2. According to the structure, the feed port is arranged on the top plate of the shielding shell 1, the cover body 6 is cylindrical, the shielding shell 1 is cylindrical with the cover body 6 at the top, the quartz enclosure 2 is cylindrical, six microwave sources are adopted, and a strong electric field area is focused above the base body 14 as can be seen from fig. 1 and 2. Three or four microwave sources may be used, but the feed ports 5 should be uniformly distributed.

Furthermore, a plurality of microwave sources and corresponding feed ports 5 are positioned on the bottom plate of the shielding shell 1 and uniformly surround the quartz enclosure 2. According to the structure, the feed port is arranged on the bottom plate of the shielding shell 1, the cover body 6 is cylindrical, the shielding shell 1 is cylindrical with the cover body 6 at the top, the quartz enclosure 2 is cylindrical, six microwave sources are adopted, and a strong electric field area is focused above the base body 14 as can be seen from fig. 3 and 4. By comparison of fig. 1 and 2, and fig. 3 and 4, the field strength of the feed port at the top plate of the shielding housing 1 is better than that of the feed port at the bottom plate of the shielding housing 1.

Furthermore, a plurality of matrixes are arranged in the reaction cavity; a plurality of mould sheets evenly surround the quartz enclosure 2; the reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of mould sheets; the microwave input cavities 8 correspond to the microwave sources one by one; the microwave sources input microwaves into the corresponding microwave input cavities 8. According to the structure, each microwave source inputs microwaves to the corresponding microwave input cavity 8, and the isolation degree between the ports is increased by the die sheet. The reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of die sheets, and the plurality of microwave input cavities 8 can be mutually communicated at the front ends.

Further, the mold sheet is a flat plate mold sheet 9; the flat plate matrix 9 passes through the base station 3 in a straight line; the top and bottom of the flat die 9 extend to the top and bottom plates of the shielding enclosure 1, respectively. With the above structure, the shielding case 1 is cylindrical with the cover 6 on the top, and when the mold sheet is a flat mold sheet 9, the microwave input cavity 8 is approximately in a sector shape. As can be seen from fig. 7 and 8, a strong electric field region is focused above the substrate 14.

Further, the die sheet is a triangular die sheet 13; the triangular die sheet 13 consists of two flat die sheets 9 with the front ends forming an included angle; the front end of the triangular mold piece 13 faces the base station 3; the top and bottom of the flat plate die 9 extend to the top plate and the bottom plate of the shielding shell 1 respectively; the front end of the microwave input cavity 8 is provided with a microwave output port 10; the microwave output port 10 faces the base platform 3; the rear end of the microwave input cavity 8 is provided with a microwave shielding port 11; the microwave shielding port 11 is sealed by a side plate of the quartz enclosure 2; the aperture of the microwave output port 10 is larger than or equal to the aperture of the microwave shielding port 11. With the above structure, the shielding case 1 is cylindrical with the cover 6 at the top, and when the mold is a triangular mold 13, the microwave input cavity 8 is approximately rectangular, or approximately trapezoidal with a large front end and a small back end, which is beneficial for the microwave to enter the substrate cavity 4 from the microwave input cavity 8, and as can be seen from fig. 11 and 12, a strong electric field area is focused above the substrate 14.

Further, the mold sheet is an elliptic surface mold sheet 12; the top and the bottom of the elliptic curved surface die 12 respectively extend to the top plate and the bottom plate of the shielding shell 1; the adjacent elliptic curved surface dies 12 are crossed; the feed opening 5 is positioned on a first focus of an ellipse where the corresponding elliptic curve surface module 12 is positioned; the base 3 is located at the second focus of the ellipse where all the elliptic curve dies 12 are located. According to the above structure, after the microwave enters the microwave input cavity 8, since the feed port 5 is located at the first focus of the ellipse where the corresponding elliptic curved surface die 12 is located and the base 3 is located at the second focus of the ellipse where all the elliptic curved surface dies 12 are located, the microwaves output from all the microwave input cavities 8 to the base cavity 4 are superimposed on the base 3, and as can be seen from fig. 16 and 17, a strong electric field area is focused above the base 14. As can be seen from comparison between fig. 7 and 8, fig. 11 and 12, and fig. 16 and 17, the strength of the field is stronger and more concentrated by using the elliptical curved surface die 12.

The invention has the beneficial effects that:

the invention discloses a multi-microwave source plasma chemical vapor deposition device, which belongs to the technical field of microwave application and comprises a shielding shell, a quartz enclosure, a base station and a plurality of microwave sources; a reaction cavity is arranged in the shielding shell; a quartz enclosure is arranged in the reaction cavity; the top and the bottom of the quartz enclosure extend to the top plate and the bottom plate of the shielding shell respectively; the quartz enclosure surrounds a substrate cavity; the top plate and the bottom plate of the shielding shell respectively close the top and the bottom of the basal body cavity; a base station is arranged in the base body cavity; the base station is used for placing the base body; the shielding shell is provided with feed ports which correspond to the microwave sources one to one; the feed ports are used for inputting microwaves into the reaction cavity outside the substrate cavity by corresponding microwave sources. The multi-microwave source plasma chemical vapor deposition device has the advantages of high quality of the manufactured diamond film, no impurities, low requirement on the microwave source power, low cost, high utilization rate of microwave energy, high electric field intensity, concentrated field intensity distribution and high isolation between microwave input ports.

Drawings

FIG. 1 shows the elevation angle field distribution simulation of the present invention using a feed port on the top plate of a shielding case 1, with a maximum multi-section electric field mode of 2.28 x 10^ 5V/m;

FIG. 2 is a simulation of the top view angular field distribution of the present invention using a feed port on the top plate of the shielded enclosure 1;

FIG. 3 shows the elevation angle field distribution simulation of the present invention using the feed port on the bottom plate of the shielding case 1, with the maximum multi-section electric field mode of 1.44 x 10^ 5V/m;

FIG. 4 is a simulation of the angular field distribution of the present invention from a top view using a feed port on the bottom plate of the shielded enclosure 1;

FIG. 5 is a schematic top view of a flat die according to the present invention;

FIG. 6 is a schematic three-dimensional structure of a flat-panel die according to the present invention;

FIG. 7 is a schematic view of the field distribution simulation of the present invention using a flat-plate die, with a maximum multi-facet electric field mode of 7.53 x 10 x 4V/m;

FIG. 8 is a simulation of a top view angular field distribution using a flat die in accordance with the present invention;

FIG. 9 is a schematic top view of the present invention using a triangular die;

FIG. 10 is a schematic three-dimensional structure of the present invention using triangular dies;

FIG. 11 is a view angle field distribution simulation of the present invention using triangular die with multi-facet electric field mode up to 1.3 x 10 x 5V/m;

FIG. 12 is a top view angular field distribution simulation using a triangular die in accordance with the present invention;

FIG. 13 is a schematic top view of an elliptical curved die in accordance with the present invention;

FIG. 14 is a schematic three-dimensional view of an elliptical curved die according to the present invention;

FIG. 15 is a schematic three-dimensional view of a base plate and platform of the present invention with the shielding shell removed, using an elliptical curved die;

FIG. 16 is a view of an angular field distribution simulation using an elliptical curved die, with a maximum multi-facet electric field mode of 1.5 x 10^ 5V/m;

FIG. 17 is a top view angular field distribution simulation using an elliptical curved die in accordance with the present invention;

FIG. 18 shows the present invention using six feed ports, with

feed ports

1,3,5 phase pi/2,

feed ports

2,4,6 phase 0, and looking down the angular field distribution simulation, with the maximum tangent plane electric field mode of 9.41 x 10^4V/m and the maximum multiple tangent plane electric field mode of 1.02 x 10^ 5V/m;

FIG. 19 is a schematic diagram of an exemplary embodiment of the present invention using six feed ports, with phase 0 for

feed ports

1,3,5 and phase 0 for

feed ports

2,4,6, for overhead angle field distribution simulation, with maximum tangent plane electric field mode of 1.33 x 10^5V/m and maximum multiple tangent plane electric field mode of 1.44 x 10^ 5V/m;

FIG. 20 shows the present invention using six feed ports, with

feed ports

1,3,5 phase pi,

feed ports

2,4,6 phase 0, looking down the angular field distribution simulation, with the maximum tangent plane electric field mode of 1.7 x 10^4V/m, and the maximum multi-tangent plane electric field mode of 9.41 x 10^ 4V/m;

FIG. 21 shows the present invention using six feed ports, with

feed ports

1,3,5 phase 3 π/4,

feed ports

2,4,6 phase 0, for overhead angle field distribution simulation, with maximum tangent plane field mode of 5.22 × 10^4V/m, and maximum multi-tangent plane field mode of 9.41 × 10^ 4V/m;

FIG. 22 shows the present invention using six feed ports, with

feed ports

1,3,5 phase 6 π/7,

feed ports

2,4,6 phase 0, for overhead angle field distribution simulation, with maximum tangent plane electric field mode of 2.97 × 10^4V/m, and maximum multi-tangent plane electric field mode of 9.41 × 10^ 4V/m;

FIG. 23 is a schematic diagram of an exemplary embodiment of the present invention using six feed ports, with phase positions of

feed ports

1,3,5 being 7 π/8 and phase positions of

feed ports

2,4,6 being 0, for overhead angle field distribution simulation, with maximum tangent plane electric field mode of 2.6 × 10^4V/m and maximum multi-tangent plane electric field mode of 9.41 × 10^ 4V/m;

FIG. 24 shows the present invention using six feed ports, with phase of

feed ports

1,3,5 being 11 π/12 and phase of

feed ports

2,4,6 being 0, for simulation of the top view angular field distribution, with maximum tangent plane electric field mode of 2.05 × 10^4V/m and maximum multiple tangent plane electric field mode of 9.41 × 10^ 4V/m;

FIG. 25 is a schematic diagram of an exemplary embodiment of the present invention using six feed ports, with

feed ports

1,3,5 phase 14 π/15 and

feed ports

2,4,6 phase 0, for overhead angle field distribution simulation, with maximum tangent plane field mode of 1.98 × 10^4V/m and maximum multiple tangent plane field mode of 9.41 × 10^ 4V/m;

fig. 26 is a schematic view of the structure of the abutment of the present invention.

In the drawings: 1-shielding shell, 2-quartz enclosure, 3-base station, 4-base chamber, 5-feed port, 6-cover body, 7-adjusting chamber, 8-microwave input chamber, 9-flat plate mold, 10-microwave output port, 11-microwave shielding port, 12-elliptic curve mold, 13-triangular mold, 14-base body, 15-base seat, 16-rotary inner cylinder, 17-rotary outer cylinder, 18-rotary middle cylinder, 19-flange, 20-rotary motor, 21-lifting seat, 22-heat exchange tube, 23-lifting mechanism, 24-mounting port, 25-mounting gap, 26-inner sealing ring, 27-outer sealing ring, 28-cavity and 29-heat exchange port.

Detailed Description

The present invention will be described in further detail below with reference to the drawings and the embodiments, but the present invention is not limited to the following examples.

The first embodiment is as follows:

see figures 1-2. The multi-microwave source plasma chemical vapor deposition device comprises a shielding shell 1, a quartz enclosure 2, a base station 3 and a plurality of microwave sources; a reaction cavity is arranged in the shielding shell 1; a quartz enclosure 2 is arranged in the reaction cavity; the top and the bottom of the quartz enclosure 2 extend to the top plate and the bottom plate of the shielding shell 1 respectively; the quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; a base station 3 is arranged in the base chamber 4; the base table 3 is used for placing a base body 14; the shielding shell 1 is provided with feed ports 5 which correspond to the microwave sources one by one; the feed openings 5 are used for the corresponding microwave sources to input microwaves into the reaction chamber outside the substrate chamber 4. According to the structure, a plurality of microwave sources input microwaves into the reaction cavity outside the matrix cavity 4 through the corresponding feed ports 5, then the microwaves penetrate through the quartz enclosure 2 to form a strong electric field on the base platform 3, and the strong electric field excites and ionizes reaction gases to form plasma, so that the deposition of a diamond film is realized. According to the multi-microwave-source plasma chemical vapor deposition device, the microwave source is adopted to feed microwaves into the reaction cavity directly, the mode conversion antenna is omitted, energy loss through the mode conversion antenna is avoided, and the utilization rate of the microwave energy is improved; the microwave source injection device has a simple structure, is easy to process, can adopt a plurality of microwave sources to inject microwaves into the reaction cavity together, and can reduce the power requirement on a single feed source, thereby reducing the cost, and the cost price of the microwave source is greatly reduced due to the reduction of the power of the microwave source. The quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; the substrate cavity 4 forms a closed space, and the quartz enclosure 2 only encloses the substrate cavity 4, so that quartz glass is not arranged above the substrate 14 on the base station 3 in the substrate cavity 4, the diamond film is not mixed with impurities, and the quality of the manufactured diamond film is high.

A cover body 6 protruding upwards is arranged on the top plate of the shielding shell 1; an adjusting cavity 7 is arranged in the cover body 6; the adjusting cavity 7 is positioned right above the base station 3; the bottom of the adjusting cavity 7 is communicated with the basal body cavity 4. With the above structure, the adjustment chamber 7 increases the space right above the base 3, so that the electric field is distributed as required, and a strong electric field area is focused above the substrate 14.

A plurality of microwave sources and corresponding feed ports 5 are located on the top plate of the shielding housing 1 and uniformly surround the quartz enclosure 2. According to the structure, the feed port is arranged on the top plate of the shielding shell 1, the cover body 6 is cylindrical, the shielding shell 1 is cylindrical with the cover body 6 at the top, the quartz enclosure 2 is cylindrical, six microwave sources are adopted, and a strong electric field area is focused above the base body 14 as can be seen from fig. 1 and 2.

Example two:

see figures 3-4. The multi-microwave source plasma chemical vapor deposition device comprises a shielding shell 1, a quartz enclosure 2, a base station 3 and a plurality of microwave sources; a reaction cavity is arranged in the shielding shell 1; a quartz enclosure 2 is arranged in the reaction cavity; the top and the bottom of the quartz enclosure 2 extend to the top plate and the bottom plate of the shielding shell 1 respectively; the quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; a base station 3 is arranged in the base chamber 4; the base table 3 is used for placing a base body 14; the shielding shell 1 is provided with feed ports 5 which correspond to the microwave sources one by one; the feed openings 5 are used for the corresponding microwave sources to input microwaves into the reaction chamber outside the substrate chamber 4. According to the structure, a plurality of microwave sources input microwaves into the reaction cavity outside the matrix cavity 4 through the corresponding feed ports 5, then the microwaves penetrate through the quartz enclosure 2 to form a strong electric field on the base platform 3, and the strong electric field excites and ionizes reaction gases to form plasma, so that the deposition of a diamond film is realized. According to the multi-microwave-source plasma chemical vapor deposition device, the microwave source is adopted to feed microwaves into the reaction cavity directly, the mode conversion antenna is omitted, energy loss through the mode conversion antenna is avoided, and the utilization rate of the microwave energy is improved; the microwave source injection device has a simple structure, is easy to process, can adopt a plurality of microwave sources to inject microwaves into the reaction cavity together, and can reduce the power requirement on a single feed source, thereby reducing the cost, and the cost price of the microwave source is greatly reduced due to the reduction of the power of the microwave source. The quartz enclosure 2 is enclosed with a substrate cavity 4; the top and bottom plates of the shielding shell 1 enclose the top and bottom of the substrate cavity 4, respectively; the substrate cavity 4 forms a closed space, and the quartz enclosure 2 only encloses the substrate cavity 4, so that quartz glass is not arranged above the substrate 14 on the base station 3 in the substrate cavity 4, the diamond film is not mixed with impurities, and the quality of the manufactured diamond film is high.

The microwave sources and the corresponding feed ports 5 are positioned on the bottom plate of the shielding shell 1 and uniformly surround the quartz enclosure 2. According to the structure, the feed port is arranged on the bottom plate of the shielding shell 1, the cover body 6 is cylindrical, the shielding shell 1 is cylindrical with the cover body 6 at the top, the quartz enclosure 2 is cylindrical, six microwave sources are adopted, and a strong electric field area is focused above the base body 14 as can be seen from fig. 3 and 4. By comparison of fig. 1 and 2, and fig. 3 and 4, the field strength of the feed port at the top plate of the shielding housing 1 is better than that of the feed port at the bottom plate of the shielding housing 1.

Example three:

see figures 5-8. On the basis of the first embodiment or the second embodiment, a plurality of dies are arranged in the reaction cavity; a plurality of mould sheets evenly surround the quartz enclosure 2; the reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of mould sheets; the microwave input cavities 8 correspond to the microwave sources one by one; the microwave sources input microwaves into the corresponding microwave input cavities 8. According to the structure, each microwave source inputs microwaves to the corresponding microwave input cavity 8, and the isolation degree between the ports is increased by the die sheet. The reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of die sheets, and the plurality of microwave input cavities 8 can be mutually communicated at the front ends.

The die is a flat die 9; the flat plate matrix 9 passes through the base station 3 in a straight line; the top and bottom of the flat die 9 extend to the top and bottom plates of the shielding enclosure 1, respectively. With the above structure, the shielding case 1 is cylindrical with the cover 6 on the top, and when the mold sheet is a flat mold sheet 9, the microwave input cavity 8 is approximately in a sector shape. As can be seen from fig. 7 and 8, a strong electric field region is focused above the substrate 14.

Example four:

see figures 9-12. On the basis of the first embodiment or the second embodiment, a plurality of dies are arranged in the reaction cavity; a plurality of mould sheets evenly surround the quartz enclosure 2; the reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of mould sheets; the microwave input cavities 8 correspond to the microwave sources one by one; the microwave sources input microwaves into the corresponding microwave input cavities 8. According to the structure, each microwave source inputs microwaves to the corresponding microwave input cavity 8, and the isolation degree between the ports is increased by the die sheet. The reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of die sheets, and the plurality of microwave input cavities 8 can be mutually communicated at the front ends.

The die sheet is a triangular die sheet 13; the triangular die sheet 13 consists of two flat die sheets 9 with the front ends forming an included angle; the front end of the triangular mold piece 13 faces the base station 3; the top and bottom of the flat plate die 9 extend to the top plate and the bottom plate of the shielding shell 1 respectively; the front end of the microwave input cavity 8 is provided with a microwave output port 10; the microwave output port 10 faces the base platform 3; the rear end of the microwave input cavity 8 is provided with a microwave shielding port 11; the microwave shielding port 11 is sealed by a side plate of the quartz enclosure 2; the aperture of the microwave output port 10 is larger than or equal to the aperture of the microwave shielding port 11. With the above structure, the shielding case 1 is cylindrical with the cover 6 at the top, and when the mold is a triangular mold 13, the microwave input cavity 8 is approximately rectangular, or approximately trapezoidal with a large front end and a small back end, which is beneficial for the microwave to enter the substrate cavity 4 from the microwave input cavity 8, and as can be seen from fig. 11 and 12, a strong electric field area is focused above the substrate 14.

Example five:

see FIGS. 13-17. On the basis of the first embodiment or the second embodiment, a plurality of dies are arranged in the reaction cavity; a plurality of mould sheets evenly surround the quartz enclosure 2; the reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of mould sheets; the microwave input cavities 8 correspond to the microwave sources one by one; the microwave sources input microwaves into the corresponding microwave input cavities 8. According to the structure, each microwave source inputs microwaves to the corresponding microwave input cavity 8, and the isolation degree between the ports is increased by the die sheet. The reaction cavity outside the substrate cavity 4 is uniformly divided into a plurality of microwave input cavities 8 by a plurality of die sheets, and the plurality of microwave input cavities 8 can be mutually communicated at the front ends.

The die is an elliptic surface die 12; the top and the bottom of the elliptic curved surface die 12 respectively extend to the top plate and the bottom plate of the shielding shell 1; the adjacent elliptic curved surface dies 12 are crossed; the feed opening 5 is positioned on a first focus of an ellipse where the corresponding elliptic curve surface module 12 is positioned; the base 3 is located at the second focus of the ellipse where all the elliptic curve dies 12 are located. According to the above structure, after the microwave enters the microwave input cavity 8, since the feed port 5 is located at the first focus of the ellipse where the corresponding elliptic curved surface die 12 is located and the base 3 is located at the second focus of the ellipse where all the elliptic curved surface dies 12 are located, the microwaves output from all the microwave input cavities 8 to the base cavity 4 are superimposed on the base 3, and as can be seen from fig. 16 and 17, a strong electric field area is focused above the base 14. As can be seen from comparison between fig. 7 and 8, fig. 11 and 12, and fig. 16 and 17, the strength of the field is stronger and more concentrated by using the elliptical curved surface die 12.

Example six:

see figures 1-26. It can be seen from the comparison of fig. 18 to 25 that, when the cover 6 is cylindrical, the shielding housing 1 is cylindrical with the cover 6 on the top, and the quartz enclosure 2 is cylindrical, when six microwave sources are used, the phases of the

feed ports

1,3,5 are 0, the phases of the

feed ports

2,4,6 are 0, the maximum tangent-plane electric field mode is 1.33 ^ 10^5V/m, the maximum multi-tangent-plane electric field mode is 1.44 ^ 10^5V/m, and the maximum field intensity is most concentrated.

Isolation test results:

isolation is defined as the ratio of the power of the local oscillator or rf signal leaking to the other ports to the input power, in dB. The isolation is the degree of interference between the two ports. The greater the isolation, the smaller the input signal at one port and the smaller the output signal at the other port.

And (3) measuring the isolation: s11 and S21 are obtained under the conditions that the port 1 is opened, the port 2 is closed and other ports are forbidden; s31: 1, opening a port, closing a port 3, and forbidding other ports; s41: port 1 is open, port 4 is closed, and the other ports are disabled. Port closure is equivalent to an output port and disabling is equivalent to the port not being present.

	S11	S21	S31	S41
					Without a die sheet	-1.2	-17.88	-17.9	-17.99
Flat plate matrix	-0.07	-29.35	-43.37	-29.56
					Triangular matrix	-0.177	-26.965	-39.906	-29.082
Elliptic curved surface template	-0.07	-34.33	-36.07	-25.47

From the above table, it can be seen that the isolation can be improved by using the mold sheet, and the elliptical surface mold sheet has not only high isolation, but also concentrated field intensity distribution and high field intensity.

The shielding shell 1 is provided with an air inlet and an air outlet; the gas inlet is used for inputting gases such as hydrogen, methane, oxygen and the like which participate in the preparation of the diamond film into the substrate cavity 4; the gas outlet is used for discharging gas in the basal body cavity 4 and vacuumizing the basal body cavity 4; the base station 3 comprises a base seat 15, a rotary inner cylinder 16, a rotary outer cylinder 17, a rotary middle cylinder 18, a flange 19, a rotary motor 20, a lifting seat 21, a heat exchange tube 22 and a lifting mechanism 23; a mounting opening 24 is formed in the bottom plate of the shielding shell 1; the mounting port 24 is provided with a rotary middle cylinder 18 through threads; the bottom of the rotary middle cylinder 18 is provided with a flange 19; the flange 19 is supported on the bottom plate of the shielding shell 1; the bottom of the base seat 15 is provided with a rotary inner cylinder 16 and a rotary outer cylinder 17; the rotary outer cylinder 17 is sleeved outside the rotary inner cylinder 16; an installation gap 25 is arranged between the rotary outer cylinder 17 and the rotary inner cylinder 16; the rotary inner cylinder 16 is inserted into the mounting gap 25; two inner sealing rings 26 are arranged on the inner side wall of the rotary middle cylinder 18; the outer side wall of the rotary middle cylinder 18 is provided with two outer sealing rings 27; the inner sealing ring 26 is used for forming a seal between the rotary middle cylinder 18 and the rotary inner cylinder 16; the outer sealing ring 27 is used for forming a seal between the rotary middle cylinder 18 and the rotary outer cylinder 17; the lifting mechanism 23 is used for driving the lifting seat 21 to move up and down along the inner side wall of the rotary middle cylinder 18; a rotating motor 20 is fixed on the lifting seat 21; the rotating motor 20 is used for driving the base seat 15, the rotating inner cylinder 16 and the rotating outer cylinder 17 to rotate integrally; a heat exchange tube 22 is arranged in the rotary inner barrel 16; the inlet and outlet of the heat exchange tube 22 are arranged on the lifting seat 21; a cavity 28 is arranged in the base body seat 15; the bottom of the base seat 15 is provided with a plurality of heat exchange ports 29; the heat exchange port 29 communicates the cavity 28 with the interior of the rotary drum 16. The lifting mechanism 23 can adopt a telescopic rod to drive the base body seat 15 to move up and down, so that the base body is positioned at the highest field intensity; the rotating motor 20 is used for driving the substrate base 15 to rotate, so that the substrate can react uniformly. The heat exchange tube 22 is introduced with a heat exchange fluid to lower the internal temperature of the rotary inner cylinder 16, and the presence of the heat exchange port 29 lowers the temperature of the cavity 28, thereby improving the reaction conditions of the substrate.

All experimental data of the invention adopt six feed ports and six microwave sources, and the power of each microwave source is 1kW, and the total microwave power is 6 kW.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The multi-microwave source plasma chemical vapor deposition device is characterized in that: comprising a shielding casing (1), a quartz enclosure (2), a base (3) and several microwave sources; There is a reaction chamber; a quartz enclosure (2) is arranged in the reaction chamber; the top and bottom of the quartz enclosure (2) respectively extend to the top plate and the bottom plate of the shielding shell (1); the quartz enclosure (2) ) is surrounded by a base body cavity (4); the top and bottom plates of the shielding shell (1) respectively close the top and bottom of the base body cavity (4); the base body cavity (4) is provided with a base (3); the The base (3) is used for placing the base body (14); the shielding shell (1) is provided with feed ports (5) corresponding to the microwave sources one-to-one; the feed ports (5) are used for the corresponding microwave source directions Microwaves are input into the reaction cavity outside the base body cavity (4); a cover body (6) protruding upward is provided on the top plate of the shielding shell (1); an adjustment cavity (7) is arranged in the cover body (6) ); the adjustment cavity (7) is located just above the base (3); the bottom of the adjustment cavity (7) is communicated with the base cavity (4); a number of microwave sources and corresponding feed ports (5) are located in the shielding shell (1) on the top plate, and evenly surrounds the quartz enclosure (2); several die are arranged in the reaction chamber; several die evenly surround the quartz enclosure (2); 4) The reaction cavities other than 4) are evenly divided into several microwave input cavities (8); the microwave input cavities (8) are in one-to-one correspondence with the microwave sources; the microwave sources input microwaves to the corresponding microwave input cavities (8); The die is an elliptical curved die (12); the top and bottom of the elliptical curved die (12) respectively extend to the top plate and the bottom plate of the shielding shell (1); The feed port (5) is located at the first focus of the ellipse where the corresponding elliptical curved die (12) is located; the base (3) is located at the second ellipse where all the elliptical curved die (12) are located on focus.