CN114369814A - MPCVD device based on microwave phase-controlled emission and temperature uniformity improvement method thereof - Google Patents
MPCVD device based on microwave phase-controlled emission and temperature uniformity improvement method thereof Download PDFInfo
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- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/50—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating using electric discharges
- C23C16/511—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating using electric discharges using microwave discharges
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Abstract
The invention discloses an MPCVD device based on microwave phased emission and a temperature uniformity improving method thereof, wherein the method comprises the following steps: exciting a plasma ball in a cavity by microwaves, wherein the microwaves are emitted by a first wave source, and a vacuum environment can be provided in the cavity; acquiring a thermal image of the plasma ball, and determining a target area according to the thermal image of the plasma ball; and focusing the electromagnetic wave energy emitted by the second wave source on a target area through the planar focusing antenna array, so as to realize temperature compensation on the target area in a focusing manner. The invention can improve the temperature distribution uniformity of the plasma spheres by temperature compensation of the plasma spheres, thereby solving the problem of uneven thickness of the prepared diamond film and realizing large-area deposition of the diamond film.
Description
Technical Field
The invention relates to the technical field of plasma excitation devices, in particular to an MPCVD device based on microwave phased emission and a temperature uniformity improvement method thereof.
Background
Diamond films possess many excellent properties, such as: the material has the advantages of extremely high hardness and elastic modulus, extremely high room temperature thermal conductivity, relatively wide forbidden band and electromagnetic wave transmission range, excellent dielectric and insulating properties, excellent semiconductor performance, good chemical stability, extremely high radiation resistance threshold and the like, so the material is a new material which is urgently needed in a plurality of traditional and high-tech fields. The microwave plasma chemical vapor deposition is the best method for preparing high-quality diamond film at present, has the advantages of no-electrode discharge, concentrated energy in a discharge area, uniform distribution and the like, and can realize the rapid deposition of the high-purity diamond film. The microwave plasma chemical vapor deposition method develops rapidly in the last 30 years with controllable high quality, and the large-area deposition of the diamond film can greatly reduce the cost and further promote the industrial application of the diamond film.
For example, a microwave plasma excitation device is adopted, which uses a magnetron to emit microwaves, and then couples the microwaves into a resonant cavity through a mode conversion antenna to promote excitation of the plasma; or, for example, a microwave is fed into a cylindrical cavity using a circular waveguide inner wall slit to excite a plasma at atmospheric pressure.
The traditional MPCVD device (namely a microwave plasma excitation device) is a single-frequency single-die cavity, a plasma field excited in the cavity has uneven temperature distribution, the deposition rate of a diamond film at a high temperature is higher than that at a low temperature, and the growth of the diamond film at a low temperature area can be inhibited to a certain extent in a high temperature area, so that the thickness of the diamond film is uneven, and the uneven thickness can cause a plurality of micro cracks, even quality defects such as cracking, bursting and the like on the surface of the diamond, thereby causing the slow deposition rate and low yield of the diamond film, and limiting the growth of large-size high-purity single crystal diamond.
Disclosure of Invention
In view of the above technical problems, the present invention aims to provide an MPCVD apparatus based on microwave phased emission and a method for improving temperature uniformity thereof, which solve the problem that the thickness of the prepared diamond film is not uniform due to the non-uniform temperature distribution of the conventional microwave plasma excitation device.
The invention adopts the following technical scheme:
the method for improving the temperature uniformity of the MPCVD device based on microwave phase-controlled emission comprises the following steps:
exciting a plasma ball in a cavity by microwaves, wherein the microwaves are emitted by a first wave source, and the cavity can provide a low-pressure environment;
acquiring a thermal image of a plasma ball, and determining a target area according to the thermal image of the plasma ball;
and focusing the electromagnetic wave energy emitted by the second wave source on a target area through the planar focusing antenna array, so as to realize temperature compensation on the target area in a focusing manner.
Optionally, the focusing the electromagnetic wave energy emitted by the second wave source on the target region by the planar focusing antenna array includes:
the plane focusing antenna array comprises at least two antennas, the second wave source sends electromagnetic waves to each antenna, each antenna transmits the electromagnetic waves to a target area, and the energy of the electromagnetic waves in the target area is strengthened by changing the phase of the electromagnetic waves transmitted by each antenna.
Optionally, the determining a target area from the thermal image includes:
and determining a low-temperature area with the temperature lower than a preset temperature threshold value on the plasma ball according to the thermal image, and taking the low-temperature area as a target area.
Optionally, the exciting the plasma ball in a cavity by microwaves includes:
the first wave source adopts a magnetron or a solid radio frequency power supply, microwaves are emitted by the magnetron or the solid radio frequency power supply, and then are coupled into the cavity through the mode conversion antenna, so that an electric field with a set mode is generated in the cavity, and the electric field ionizes gas in the cavity, so that a plasma ball is excited.
An MPCVD apparatus based on microwave phased emission, comprising: the plasma ball thermal imaging system comprises a first wave source, a second wave source, a mode conversion antenna, a cavity for providing a low-pressure environment, a planar focusing antenna array, a thermal imager for acquiring a thermal image of a plasma ball and a control unit, wherein the first wave source is used for transmitting microwaves;
wherein the microwave emitted by the first wave source is coupled into the cavity through a mode conversion antenna so as to excite a plasma ball; the thermal imager sends the acquired thermal image of the plasma ball to the control unit; the control unit is used for determining a target area according to the thermal image, controlling the plane focusing antenna array to focus the electromagnetic wave energy of the second wave source on the target area, and realizing temperature compensation on the target area in a focusing mode.
Optionally, the planar focusing antenna array includes two or more patch antennas.
Optionally, a quartz ring for providing a low-pressure environment is arranged inside the cavity, and a deposition table for receiving a plasma ball is arranged above the quartz ring.
Optionally, the planar focusing antenna array is disposed on the upper surface of the cavity, so that the planar focusing antenna array focuses electromagnetic wave energy of the second wave source on the target region.
An electronic device, comprising: at least one processor, and a memory communicatively coupled to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being executable by the at least one processor to enable the at least one processor to perform the temperature uniformity improvement method.
A computer storage medium having stored thereon a computer program which, when executed by a processor, implements the temperature uniformity improvement method.
Compared with the prior art, the invention has the beneficial effects that:
the invention realizes power feeding through a first wave source (namely a main source) and a second wave source (namely a slave source), for example, the power feeding is realized by using the sources with the frequencies of 915MHz and 5.8 GHz; the temperature of the plasma ball is observed through temperature feedback of the thermal imager, a target area is determined, then temperature compensation is realized on the target area through the planar focusing antenna array, for example, the phase of each antenna in the planar focusing antenna array is adjusted to focus energy radiated by each antenna unit on the target area to realize temperature compensation, and the temperature distribution uniformity of the plasma ball is improved through temperature compensation on the plasma ball, so that the problem of uneven thickness of the prepared diamond film is solved, and large-area deposition of the diamond film can be realized.
Drawings
FIG. 1 is a schematic flow chart of a method for improving temperature uniformity of an MPCVD apparatus based on microwave phased emission according to an embodiment of the present invention;
FIG. 2a is a block diagram of an MPCVD apparatus based on microwave phased emission according to an embodiment of the present invention;
FIG. 2b is a schematic diagram of an MPCVD apparatus based on microwave phased emission according to an embodiment of the present invention;
FIG. 2c shows a schematic diagram of a planar focusing antenna array of the present invention;
FIG. 3a is a longitudinal section of an electric field distribution of a target area after temperature compensation when the distance between an ideal focus point and an antenna surface is 200mm according to an embodiment of the present invention;
FIG. 3b is a cross-section of the electric field distribution of the target area after temperature compensation when the distance between the ideal focus point and the antenna surface is 200mm according to an embodiment of the present invention;
FIG. 4a is a longitudinal section of the electric field distribution of the target area after temperature compensation when the distance between the ideal focus point and the antenna surface is 400mm according to an embodiment of the present invention;
FIG. 4b is a cross-section of the electric field distribution of the target area after temperature compensation when the distance between the ideal focus point and the antenna surface is 400mm according to an embodiment of the present invention;
FIG. 5a is a longitudinal section of an electric field distribution of a target area after temperature compensation when the distance between an ideal focus point and an antenna surface is 800mm according to an embodiment of the present invention;
FIG. 5b is a cross-section of the electric field distribution of the target area after temperature compensation when the distance between the ideal focus point and the antenna surface is 800mm according to an embodiment of the present invention;
FIG. 6a is a longitudinal section of an electric field distribution when a planar focusing antenna array is scanned transversely according to an embodiment of the present invention;
FIG. 6b is a cross-section of an electric field distribution during a horizontal scan of the planar focusing antenna array according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and specific embodiments, and it should be noted that, in the premise of no conflict, the following described embodiments or technical features may be arbitrarily combined to form a new embodiment:
the first embodiment is as follows:
referring to fig. 1-7, fig. 1 shows a method for improving temperature uniformity of an MPCVD apparatus based on microwave phased emission according to the present invention, comprising the following steps:
step S1, exciting a plasma ball 8 in a cavity 3 through microwaves, wherein the microwaves are emitted by a first wave source 1, and a low-pressure environment can be provided in the cavity 3;
in this embodiment, the first wave source 1 may also be referred to as a master source, and the second wave source 7 may also be referred to as a slave source; the operating frequency of the primary source is 915MHz and the operating frequency of the secondary source, i.e. the planar focusing antenna array 6, is 5.8 GHz. The first wave source 1 may be a high power source and the second wave source 7 may be composed of a plurality of low power microwave sources, the main source being used to emit microwaves, which excite the plasma sphere 8.
Specifically, the exciting of the plasma ball 8 in the cavity 3 by the microwave includes:
the first wave source 1 adopts a magnetron, the magnetron emits microwaves, and the microwaves are coupled into the cavity 3 through the mode conversion antenna 2, so that an electric field with a set mode is generated in the cavity 3, and the electric field ionizes gas in the cavity 3, so that a plasma ball 8 is excited.
It should be noted that the plasmonic ball 8, also called a plasmonic ball, a lightning ball or a astrobus, etc., can be manufactured using a laser, a microwave generator or any strong electromagnetic field. During the manufacturing process, as the bonds of the molecules break, the atoms gain or lose electrons, forming ions, and the plasma is composed of free electrons and positively charged ions (cations), but it is entirely electrically neutral.
In the above implementation, the microwave excited by the main source magnetron propagates along the rectangular waveguide in TE10 mode, and generates a field of a desired mode in the resonant cavity via the mode conversion antenna 2, and the electric field ionizes the reaction gas to excite the plasmon ball 8.
Step S2, acquiring a thermal image of the plasma ball 8, and determining a target area according to the thermal image of the plasma ball 8;
it should be noted that the thermal imager 4 may be a device that converts the invisible infrared energy emitted by the object into visible thermal images, where the different colors on the top of the thermal images represent the different temperatures of the object being measured.
Specifically, the determining a target area according to the thermal image includes: and acquiring a low-temperature area with the display temperature lower than a preset temperature threshold in the thermal image, and taking the low-temperature area as a target area.
In the embodiment, the thermal imager 4 can monitor the temperature distribution of the plasma ball 8 in real time, and the feeding phase, the output power and the working time of the slave source are changed through the feedback of the thermal imager 4 on the temperature.
And step S3, focusing the electromagnetic wave energy emitted from the second source on the target area through the plane focusing antenna array 6, and realizing temperature compensation on the target area in a focusing manner.
Specifically, the focusing the electromagnetic wave energy emitted by the second wave source 7 on the target area by the planar focusing antenna array 6 includes:
the plane focusing antenna array 6 comprises at least two antennas, the second wave source 7 sends electromagnetic waves to each antenna, each antenna propagates the electromagnetic waves to a target area, and the energy of the electromagnetic waves in the target area is strengthened by changing the phase of the electromagnetic waves transmitted by each antenna.
Specifically, the emission phase difference of each antenna can be controlled by controlling the emission phase difference of a series of second wave sources 7, so that the energy focusing of the target area is realized.
In this embodiment, when a plurality of electromagnetic waves of the same type propagate at the same point, the total amplitude of the point is a vector sum of the amplitudes of all the electromagnetic waves. Electromagnetic waves of the same frequency are input from a source to each antenna, and the potential difference of the electromagnetic waves at the same point is made to be even multiples of pi by changing the phase, so that the total amplitude of the point is the sum of the amplitudes. By setting the frequency, power, heating time, and phase of the slave source, it is possible to realize directional heating, that is, heating only a desired target region, and further, it is possible to realize temperature compensation of the plasma bulb 8.
In specific implementation, in order to realize the focusing of the energy radiated by the antenna on a certain specific point of the near field region thereof, a near field focusing antenna can be adopted, and the electromagnetic waves are superposed in phase at the target point by controlling the phase of each radiating element on the array antenna.
In the implementation, the uniformity of the plasma can be improved by temperature compensating the target area in a focused manner by the planar focusing antenna array 6, for example, by temperature compensating the target area within a given time and power.
Example two:
referring to fig. 2a, fig. 2a is a block diagram of an MPCVD apparatus based on microwave phased emission according to the present invention, which includes: the plasma display device comprises a first wave source 1 for emitting microwaves, a second wave source 7, a mode conversion antenna 2, a cavity 3 for providing a low-pressure environment, a planar focusing antenna array 6, a thermal imager 4 for acquiring a thermal image of a plasma ball 8 and a control unit 5;
wherein, the microwave emitted by the first wave source 1 is coupled into the cavity 3 through the mode conversion antenna 2, so as to excite the plasma ball 8; the thermal imager 4 sends the acquired thermal image of the plasma ball 8 to the control unit 5; the control unit 5 determines a target area according to the thermal image and controls the planar focusing antenna array 6 to focus the electromagnetic wave energy of the second wave source 7 on the target area.
Specifically, referring to fig. 2c, fig. 2c shows a schematic diagram of a planar focusing antenna array according to the present invention, where the planar focusing antenna array 6 includes two or more patch antennas 61.
Specifically, the cavity 3 is internally provided with a quartz ring for providing a low-pressure environment, and a deposition table for receiving the plasma ball 8 is arranged above the quartz ring.
Referring to fig. 2b, fig. 2b is a schematic diagram of an MPCVD apparatus based on microwave phased emission according to the present invention, specifically, the planar focusing antenna array 6 is disposed on the upper surface of the cavity 3, so that the planar focusing antenna array 6 focuses the electromagnetic wave energy of the second wave source 7 on the target area.
In the implementation process, the planar focusing antenna array 6 is used for compensating a region with a relatively low temperature in the plasma field, for example, the planar focusing antenna array 6 with multiple sources is added above the cavity 3, the feed phase of each port of the planar antenna is changed, and the compensation of the portion with the low temperature in the plasma field is realized, so that the uniformity of the plasma is improved, and the diamond film deposition with large area, high power and high efficiency is realized.
The working principle of the device is as follows:
the first wave source 1 delivers energy into the cavity 3 from below the device, and a concentrated electric field is formed in the area above the deposition table, and the electric field ionizes the gas to form a plasma ball 8. The bottom of the cavity 3 is provided with a quartz ring which can isolate air and provide a low-pressure environment, a deposition table above the quartz ring plays a role in bearing the plasma ball 8, the planar focusing antenna array 6 is arranged on the upper surface of the cavity 3 and is a 3 x 3 patch antenna structure, each patch antenna is an independent source, and the output power and the feed phase of each antenna can be independently controlled, so that the focusing effect is achieved.
Conventional antennas typically operate in their radiation far field region. The device of the application requires that the energy radiated by the antenna is concentrated on a certain point of the near field area, so the near field focusing antenna is designed, and the essence is to control the phase of each radiating element on the array antenna so as to realize in-phase superposition of electromagnetic waves at a target point.
The structure of the planar focusing antenna array 6 can be selected according to actual situations, for example, the antenna type can be a microstrip antenna, a helical antenna, or the like, and the size and the array of the antenna can also be selected, for example, in the form of n × n or m × n.
The focusing area of the near-field focusing array antenna is a Fresnel area. Setting D as the aperture of the antenna, lambda as the wavelength and R as the distance from some point in space to the surface of the antenna, the induction near field region is
The area of (a); radiating the near field region (Fresnel region) in
And R is less than or equal to 2D2Between/lambda; the radiation far-field region is R & gt 2D2Region of/λ. According to the radiation principle of the antenna, the radiation energy of the Fresnel zone is formed by superposition of radiation fields of radiation sources in the radiation zone, and is determined by attenuation and phase delay caused by a propagation path determined by the energy of the radiation sources and medium parameters passing through the space, so that the radiation characteristics of the elements of the planar focusing antenna array 6 are formed.
Specifically, the phase difference between the units is compensated by changing the distance of the transmission lines between the array elements, so that the phase between the array elements reaches a certain focus of the near field by a multiple of one wavelength to realize focusing, and the phase from the radiation field of each radiation array element to the focus is as follows:
wherein (x)m，yn) The coordinate, x, of the mth radiation unit on the abscissa and the nth radiation unit on the ordinate with the projection point of the focusing point to the surface of the antenna as the centermIs the abscissa, y, of the radiation unitnIs the ordinate, z, of the radiation elementfThe distance of the focal point from the surface of the excitation antenna.
Taking the array element with coordinates (x2, y2) as a reference unit, the phase difference needed to be compensated by other array elements is:
wherein, theta22Feed phase, θ, set as required for the cloud of coordinates (x2, y2)mnIs the actual phase at the coordinate (x2, y2) to the focus, θmn' phase differences that need to be compensated for other array elements.
The phase difference required to be compensated by each array element under different focusing points can be calculated by the method, and the temperature compensation of different areas is realized.
In the implementation, the effect after temperature compensation is as shown in fig. 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b below, where R is the distance between the ideal focus point and the antenna surface.
Wherein, fig. 3a and fig. 3b are respectively the longitudinal section and the transverse section of the electric field distribution of the target area after the temperature compensation is realized when the distance between the ideal focusing point and the antenna surface is 200 mm. In fig. 3a and 3b, R is 200mm, and it can be seen that the center of the target area has a significant focusing effect, and the diameter of the focusing area is about 6 cm.
Wherein, fig. 4a and fig. 4b are respectively the longitudinal section and the transverse section of the electric field distribution of the target area after the temperature compensation is realized when the distance between the ideal focusing point and the antenna surface is 400 mm. In fig. 4a and 4b, R is 400mm, and it can be seen that the center of the target area also has a significant focusing effect, and the focusing area is larger, about 14cm in diameter.
Wherein, fig. 5a and 5b are respectively the longitudinal section and the transverse section of the electric field distribution of the target area after the temperature compensation is realized when the distance between the ideal focusing point and the antenna surface is 800 mm. In fig. 5a and 5b, where R is 800mm, it can be seen that the area of focus is larger, with a diameter of about 17cm, but the focal spot field strength maximum at this distance has a certain decrease.
Fig. 6a and 6b are a longitudinal section and a transverse section of the electric field distribution when the planar focusing antenna array 6 scans transversely, respectively, and it can be seen that the antenna has a significant effect in transverse scanning, in fig. 6a and 6b, R is 200mm, the focal spot is shifted leftwards and upwards, and the shift distance is about 7 cm. The lateral offset distance can be adjusted by phase as desired.
From the above embodiments, it can be seen that the device of the present invention can realize directional temperature compensation in the near field region (i.e. temperature compensation of the target region), and improve the uniformity of the plasma ball 8, thereby achieving the purpose of efficiently depositing the diamond film.
It should be noted that the growth of diamond film is a long time process, and the stability of plasma is especially important. The stability of the plasma determines the uniform distribution of active atoms and active groups of the plasma, thereby influencing the spatial distribution of the plasma in a deposition area and the concentration evolution in the deposition time and determining the growth quality of the diamond film. There is always a fraction of the radiated energy of an actual plasma to escape the plasma and therefore there is no balance between species and radiation. However, a thermal equilibrium can be established in the space containing a large number of particles and enabling sufficient energy exchange, i.e. when the electron density is sufficiently high to make the electron collision process play a determining role in the processes of excited ionization, recombination, etc. in the plasma. The electron temperature rises, and the electron obtains higher energy, so that more neutral gas molecules and atoms are impacted and ionized, and higher plasma density can be obtained.
In the implementation process, the first wave source 1 (i.e. the main source) and the second wave source 7 (i.e. the slave source) realize power feeding, for example, the power feeding is realized by using the sources with the frequencies of 915MHz and 5.8 GHz; the temperature of the plasma ball 8 is observed through temperature feedback of the thermal imager 4, a target area is determined, specifically, a low-temperature area is selected to realize temperature compensation, and then the target area is subjected to temperature compensation through the planar focusing antenna array 6, for example, the phase of each antenna in the planar focusing antenna array 6 is adjusted to focus energy radiated by each antenna unit in a designated area to realize temperature compensation, so that the uniformity of the plasma ball 8 is improved through temperature compensation.
Example three:
fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application, and an electronic device 100 for implementing a method for improving temperature uniformity of an MPCVD device based on microwave phased emission according to an embodiment of the present application can be described with reference to the schematic diagram shown in fig. 7.
As shown in fig. 7, an electronic device 100 includes one or more processors 102, one or more memory devices 104, and the like, which are interconnected via a bus system and/or other type of connection mechanism (not shown). It should be noted that the components and structure of the electronic device 100 shown in fig. 7 are only exemplary and not limiting, and the electronic device may have some of the components shown in fig. 7 and may have other components and structures not shown in fig. 7 as needed.
The processor 102 may be a Central Processing Unit (CPU) or other form of processing unit having data processing capabilities and/or instruction execution capabilities, and may control other components in the electronic device 100 to perform desired functions.
The storage 104 may include one or more computer program products that may include various forms of computer-readable storage media, such as volatile memory and/or non-volatile memory. The volatile memory may include, for example, Random Access Memory (RAM), cache memory (cache), and/or the like. The non-volatile memory may include, for example, Read Only Memory (ROM), hard disk, flash memory, etc. On which one or more computer program instructions may be stored that may be executed by processor 102 to implement the functions of the embodiments of the application (as implemented by the processor) described below and/or other desired functions. Various applications and various data, such as various data used and/or generated by the applications, may also be stored in the computer-readable storage medium.
The invention also provides a computer storage medium on which a computer program is stored, in which the method of the invention, if implemented in the form of software functional units and sold or used as a stand-alone product, can be stored. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer storage medium and used by a processor to implement the steps of the embodiments of the method. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer storage medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer storage media may include content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer storage media that does not include electrical carrier signals and telecommunications signals as subject to legislation and patent practice.
Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present invention.
Claims (10)
1. The method for improving the temperature uniformity of the MPCVD device based on microwave phase-controlled emission is characterized by comprising the following steps:
exciting a plasma ball in a cavity by microwaves, wherein the microwaves are emitted by a first wave source, and the cavity can provide a low-pressure environment;
acquiring a thermal image of the plasma ball, and determining a target area according to the thermal image of the plasma ball;
and focusing the electromagnetic wave energy emitted by the second wave source on a target area through the planar focusing antenna array, so as to realize temperature compensation on the target area in a focusing manner.
2. The method for improving the temperature uniformity of an MPCVD apparatus based on microwave phased emission according to claim 1, wherein the focusing the electromagnetic wave energy emitted from the second wave source on the target area by the planar focusing antenna array comprises:
the plane focusing antenna array comprises at least two antennas, the second wave source sends electromagnetic waves to each antenna, each antenna transmits the electromagnetic waves to a target area, and the energy of the electromagnetic waves in the target area is strengthened by changing the phase of the electromagnetic waves transmitted by each antenna.
3. The method for improving temperature uniformity of an MPCVD apparatus based on microwave phased emission according to claim 1, wherein said determining a target area from said thermal image comprises:
and determining a low-temperature area with the temperature lower than a preset temperature threshold value on the plasma ball according to the thermal image, and taking the low-temperature area as a target area.
4. The method of claim 1, wherein the exciting a plasma sphere in a cavity by microwaves comprises:
the first wave source adopts a magnetron or a solid radio frequency power supply, microwaves are emitted by the magnetron or the solid radio frequency power supply, and then are coupled into the cavity through the mode conversion antenna, so that an electric field with a set mode is generated in the cavity, and the electric field ionizes gas in the cavity, so that a plasma ball is excited.
5. An MPCVD apparatus based on microwave phased emission, comprising: the plasma ball thermal imaging system comprises a first wave source, a second wave source, a mode conversion antenna, a cavity for providing a low-pressure environment, a planar focusing antenna array, a thermal imager for acquiring a thermal image of a plasma ball and a control unit, wherein the first wave source is used for transmitting microwaves;
wherein the microwave emitted by the first wave source is coupled into the cavity through a mode conversion antenna so as to excite a plasma ball; the thermal imager sends the acquired thermal image of the plasma ball to the control unit; the control unit determines a target area according to the thermal image and controls the plane focusing antenna array to focus the electromagnetic wave energy of the second wave source on the target area, so that the temperature compensation of the target area is realized in a focusing mode.
6. The microwave phased transmission-based MPCVD apparatus according to claim 5, wherein the planar focusing antenna array comprises two or more patch antennas.
7. The microwave phased emission-based MPCVD apparatus according to claim 5, wherein a quartz ring for providing a low pressure environment is arranged inside the chamber body, and a deposition table for receiving plasma balls is arranged above the quartz ring.
8. The microwave phased emission-based MPCVD apparatus according to claim 5, wherein the planar focusing antenna array is disposed on the upper surface of the chamber, such that the planar focusing antenna array focuses the electromagnetic wave energy of the second wave source on the target area.
9. An electronic device, comprising: at least one processor, and a memory communicatively coupled to the at least one processor, wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the temperature uniformity improvement method of any one of claims 1-7.
10. A computer storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the temperature uniformity improvement method of any of claims 1-7.
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