Plasma characteristic three-dimensional diagnosis equipment and method based on emission spectrum

Abstract

A plasma characteristic three-dimensional diagnosis device and method based on an emission spectrum, and the device comprises a spectrometer which is used for scanning a plurality of preset positions around a plasma, and obtaining the three-dimensional emission spectrum of the plasma; the processor is used for obtaining three-dimensional temperature distribution and three-dimensional concentration distribution of the plasma according to a collision-radiation model of the plasma and the three-dimensional emission spectrum; in-situ point-by-point scanning can be performed on a plurality of points around the plasma to obtain the three-dimensional emission spectrum of the plasma, equipment is simple, rich emission spectrum information of the plasma can be obtained by only needing a spectrograph, and then temperature and concentration three-dimensional distribution of the plasma is obtained by combining a radiation-collision model of the plasma. And the three-dimensional in-situ quantitative detection of the plasma is realized.

Description

Technical Field

[0001] The present invention relates to the field of plasma diagnosis, and in particular to a three-dimensional diagnosis device and method of plasma characteristics based on emission spectroscopy. Background Art

[0002] Plasma diagnostic methods are mainly divided into two categories: electrical and optical. Electrical methods include Langmuir probes, mass spectrometers, etc., and optical methods include emission spectroscopy, absorption spectroscopy, laser induced fluorescence, optical probes, etc.; electrical methods are all invasive measurements that will interfere with the plasma, and the maximum operating temperature of the Langmuir probe generally does not exceed 1000°C, which cannot meet the measurement of plasma temperatures from room temperature to tens of millions of degrees Celsius; in optical methods, since light propagates in a straight line, the optical method directly measures the average value of the emission intensity at all spatial points within the observation angle after line integration, and cannot directly achieve three-dimensional measurement. Absorption spectroscopy, laser induced fluorescence and optical probe methods generally have the problems of single measurement information, complex and expensive equipment. Summary of the invention

[0003] The embodiments of the present application provide a three-dimensional diagnostic device and method for plasma characteristics based on emission spectroscopy, which can perform in-situ point-by-point scanning at multiple points around the plasma to obtain a three-dimensional emission spectrum of the plasma. The equipment is simple and only requires one spectrometer to achieve three-dimensional in-situ quantitative detection of the plasma.

[0004] On the one hand, an embodiment of the present application provides a plasma characteristic three-dimensional diagnostic device based on emission spectroscopy, comprising: A spectrometer, used to scan a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; A processor is used to obtain a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma according to a collision-radiation model of the plasma and the three-dimensional emission spectrum.

[0005] On the other hand, an embodiment of the present application further provides a plasma characteristic three-dimensional diagnosis method based on emission spectrum, the method being performed by the plasma characteristic three-dimensional diagnosis device based on emission spectrum described in the above embodiment, comprising: The spectrometer scans a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; The processor obtains the collision-radiation model of the plasma and generates a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma in combination with the three-dimensional emission spectrum.

[0006] Compared with the related art, the three-dimensional diagnostic device and method of plasma characteristics based on emission spectroscopy in the embodiment of the present application can perform in-situ point-by-point scanning at multiple points around the plasma to obtain the three-dimensional emission spectrum of the plasma. The equipment is simple and only requires a spectrometer to obtain rich emission spectrum information of the plasma, and then combine the radiation-collision model of the plasma to obtain the three-dimensional distribution of temperature and concentration of the plasma, thereby realizing three-dimensional in-situ quantitative detection of the plasma.

[0007] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0009] Figure 1 A schematic diagram of a plasma characteristic three-dimensional diagnostic device based on emission spectroscopy according to an embodiment of the present application; Figure 2 A schematic diagram of a plasma characteristic three-dimensional diagnostic device and a plasma generating device based on emission spectroscopy according to an embodiment of the present application; Figure 3 This is a flow chart of a three-dimensional diagnosis method of plasma characteristics based on emission spectroscopy according to an embodiment of the present application. DETAILED DESCRIPTION

[0010] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0011] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0012] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0013] Plasma is the fourth state of matter. Due to its unique physical and chemical properties, it has a wide range of applications in many fields, such as plasma cutting, etching, air purification, material synthesis, plasma propulsion, etc. Realizing three-dimensional in-situ quantitative monitoring of plasma is of great significance for evaluating and improving the actual application effect of plasma.

[0014] The present application embodiment provides a plasma characteristic three-dimensional diagnostic device based on emission spectroscopy, such as Figure 1 As shown, including: A spectrometer, used to scan a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; A processor is used to obtain a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma according to a collision-radiation model of the plasma and the three-dimensional emission spectrum.

[0015] In this embodiment, a plurality of predetermined positions are evenly distributed around the plasma so as to obtain the emission spectrum of the plasma in various directions, and the emission spectra obtained at all predetermined positions form a three-dimensional emission spectrum of the plasma.

[0016] In this embodiment, the spectrometer may be a photomultiplier tube spectrometer, a CCD (Charge-Coupled Device) spectrometer, a CMOS (Complementary Metal-Oxide-Semiconductor) spectrometer, an avalanche photodiode spectrometer or the like.

[0017] In this embodiment, the collision-radiation model of the plasma may be a theoretical collision-radiation model that describes the kinematic process of particles in the plasma.

[0018] The three-dimensional diagnostic equipment for plasma characteristics based on emission spectroscopy in this embodiment can perform in-situ point-by-point scanning at multiple points around the plasma to obtain the three-dimensional emission spectrum of the plasma. The equipment is simple and only requires a spectrometer to obtain rich emission spectrum information of the plasma, and then combine the radiation-collision model of the plasma to obtain the three-dimensional distribution of temperature and concentration of the plasma, thereby realizing three-dimensional in-situ quantitative detection of the plasma.

[0019] In an exemplary embodiment, the spectrometer includes a collimator and a detector connected by an optical fiber, such as Figure 2 As shown; The collimator is used to collect the emission spectrum of the plasma in parallel at each of the predetermined positions, and transmit the collected emission spectrum signal to the detector through the optical fiber; The detector is used to convert the emission spectrum signal collected at each of the predetermined positions into an electrical signal and send the electrical signal to the processor.

[0020] In this embodiment, the collimator can shape the emission spectrum of the divergent plasma into a parallel light beam, thereby ensuring that the emission spectrum of the plasma is efficiently and accurately transmitted to the detector.

[0021] In an exemplary embodiment, the plasma characteristic three-dimensional diagnostic device based on emission spectroscopy is as follows: Figure 2 As shown, it also includes: A slide rail, comprising an annular track and a slider; the slider is used to receive a position signal sent by the processor, and slide the carried object platform along the annular track based on the position signal; The loading platform is provided with a rotation axis, the rotation axis is used to receive the position signal sent by the processor, and adjust the height of the collimator and the rotation angle of the collimator in the normal plane of the rotation axis based on the position signal; The position signals correspond to the predetermined positions one by one, and each of the position signals includes a slider position sub-signal, a collimator height sub-signal, and a collimator rotation angle sub-signal.

[0022] In this embodiment, the annular track can be a circular track, which includes an inner track and an outer track. A loading platform is installed on the upper part of the slider, a rotating shaft is installed on the loading platform, and a collimator is installed on the rotating shaft. The slider drives the loading platform to move on the annular track, which drives the collimator to move along the annular track, and the rotating shaft can be adjusted in height and rotation angle to achieve the adjustment of the height and rotation angle of the collimator. The collimator can be located at the corresponding predetermined position through the position signal to achieve the collection of the emission spectrum at the predetermined position.

[0023] In an exemplary embodiment, the plasma characteristic three-dimensional diagnostic device based on emission spectroscopy is as follows: Figure 2 As shown, it also includes: A plasma generating device, comprising a chamber and an air inlet device, an exciter and a base; The cavity is located within the inner track of the annular track; The base is located at the lower part of the cavity, and is used to focus the plasma above the base; The air inlet device is used to introduce external gas to be ionized into the cavity; The energizer is located in the cavity and is used to ionize the gas to be ionized to generate the plasma.

[0024] In an exemplary embodiment, the cavity is a cylinder, and a plurality of observation windows are arranged in the cavity at positions surrounding the plasma. The plurality of observation windows are evenly distributed along the circumferential direction and the height direction of the cavity, and each of the observation windows is used for the collimator to collect the emission spectrum of the plasma.

[0025] In this embodiment, the cavity may be a cylinder, and the central axis of the cavity coincides with the central axis of the base and the central axis of the circular annular track, thereby improving the parameter consistency of the emission spectra obtained at different predetermined positions.

[0026] In this embodiment, the observation window provided on the cavity is as follows: Figure 2 As shown, Figure 2This is only an exemplary description and is not intended to be a limitation of the present application. The number of rows and columns of observation windows can be set according to the actual plasma three-dimensional diagnostic needs. For example, a column of observation windows can be set every 10 degrees, and the number of rows of observation windows can be set to 2 rows; or a column of observation windows can be set every 20 degrees, and the number of rows of observation windows can be set to 3 rows. When the slider moves along the circular track, the collimator can be moved to a position facing a column of observation windows, and the height of the rotating axis can be adjusted to adjust the height of the collimator. The collimator can be aligned with one of the observation windows in the column, and the left and right swing angle of the rotating axis can be adjusted to achieve the left and right swing of the collimator within the range of the observation window, that is, the emission spectrum signals of the plasma can be obtained at multiple predetermined positions in one observation window.

[0027] In the present embodiment, the setting of the observation window facilitates the spectrometer to obtain the emission spectrum of the plasma at each predetermined position, and each slider position sub-signal corresponds to multiple collimator height sub-signals, and each collimator height sub-signal corresponds to multiple collimator rotation angle sub-signals; that is, each time the slider moves to a position, the collimator can obtain the emission spectrum of the plasma at multiple heights, and at the same time, the collimator at each height can correspond to multiple rotation angles, and the emission spectrum of the plasma can be obtained at each rotation angle.

[0028] In this embodiment, multiple position signals can be divided into several position signal sets, and the slider position sub-signals corresponding to all the position signals included in each position signal set are the same; each position signal set can be divided into several position signal groups, and the collimator height sub-signals corresponding to all the position signals included in each position signal group are the same, as shown in Table 1. The position signals in Table 1 are all exemplary descriptions and are not intended to limit the position signals of the present application. For example, the circular annular track coincides with the central axis of the cylindrical cavity, and a two-dimensional coordinate system is established with the axis O of the annular track as the coordinate origin. A column of observation windows is set every 20 degrees starting from 0 degrees on the cavity, and each column of observation windows includes two upper and lower observation windows (a lower observation window and an upper observation window), that is, a slider position is set every 20 degrees starting from 0 degrees on the circular annular track; at each slider position, there are two corresponding heights of observation windows, That is, two collimator height positions are set; at each collimator height position, the position of the collimator centerline opposite to the axis O is 0 degrees, and the collimator is rotated 5 degrees to the left and right respectively to form collimator rotation angle positions of 0 degrees, -5 degrees and +5 degrees; when the processor sends a position signal, it sends a position signal set before sending the next position signal set; when sending a position signal set, it sends a position signal group before sending the next position signal group; when sending a position signal group, the position signals are sent sequentially at the same time interval. By sending the position signal in this way, the spectrometer can set the collimator to different heights and different rotation angles at one slider position to obtain the emission spectrum, and then the slider moves to the next position to obtain the emission spectrum, thereby improving the efficiency of the spectrometer in obtaining the emission spectrum; Table 1 uses the slider position at two positions of 0 degrees and 20 degrees as examples.

[0029] Table 1 Position signal table (partial) In an exemplary embodiment, the gas to be ionized may include one or more of the following gases: hydrogen, methane, nitrogen, oxygen, argon, acetylene, borane and phosphine. These gases to be ionized are described as examples and are not intended to limit the present application, so they will not be described one by one.

[0030] In this embodiment, the gas to be ionized can be a single gas or a mixture of multiple gases.

[0031] In an exemplary embodiment, the exciter includes one or more of the following exciters: a direct current electric field exciter, an alternating current electric field exciter, and a high temperature heating exciter.

[0032] In this embodiment, the DC electric field exciter may be a DC arc plasma exciter, a DC glow discharge plasma exciter, a DC corona discharge plasma exciter, or the like.

[0033] In this embodiment, the AC electric field exciter may be a microwave plasma exciter, a radio frequency discharge plasma exciter, a capacitively coupled plasma exciter, or the like.

[0034] In this embodiment, the high temperature heating exciter may be a neutral particle beam injection heating plasma exciter, a magnetic pump heating plasma exciter, or the like.

[0035] The embodiment of the present application also provides a plasma characteristic three-dimensional diagnosis method based on emission spectrum, the method is performed by the plasma characteristic three-dimensional diagnosis device based on emission spectrum described in the above embodiment, including steps S100-S200, such as Figure 3 As shown: S100: The spectrometer scans a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; S200: The processor obtains the collision-radiation model of the plasma, and generates a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma in combination with the three-dimensional emission spectrum.

[0036] In this embodiment, before executing step S100, step S000 may be executed: S000: The gas inlet device introduces the gas to be ionized into the cavity of the plasma generating device, and the exciter ionizes the gas to be ionized to generate the plasma, wherein the plasma is focused above the base.

[0037] In this embodiment, the spectrometer acquires the emission spectrum of the plasma at each predetermined position, and the three-dimensional emission spectrum of the plasma can be obtained based on the emission spectra of all the predetermined positions.

[0038] In an exemplary embodiment, the step S100 includes: performing steps S110-S130 at each of the predetermined positions: S110: the processor sends a position signal to the slider and the rotation axis, and the slider and the rotation axis move the collimator of the spectrometer to the predetermined position corresponding to the position signal based on the position signal; S120: The collimator collects the emission spectrum of the plasma in parallel through the observation window at the predetermined position, and transmits the collected emission spectrum signal to the detector through the optical fiber; S130: The detector converts the emission spectrum signal of the predetermined position into an electrical signal.

[0039] In this embodiment, the position signal corresponds to the predetermined position one by one.

[0040] In this embodiment, each position signal may include three sub-signals: a slider position sub-signal, a collimator height sub-signal, and a collimator rotation angle sub-signal; when the processor sends a position signal, the processor sends the slider position sub-signal of the position signal to the slider, and the slider moves to the corresponding position along the circular track based on the slider position sub-signal; the processor sends the collimator height sub-signal and the collimator rotation angle sub-signal of the position signal to the rotating axis, and the rotating axis adjusts the height of the collimator and the rotation angle in the normal plane of the rotating axis according to the collimator height sub-signal and the collimator rotation angle sub-signal; the three sub-signals jointly determine the position of the collimator.

[0041] In an exemplary embodiment, the step S200 includes steps S210-S220: S210: the processor acquires the electrical signal corresponding to each of the predetermined positions and the collision-radiation model of the plasma; S220: The processor obtains a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma based on the electrical signals at all predetermined positions and the collision-radiation model.

[0042] In order to illustrate the plasma characteristic three-dimensional diagnosis method based on emission spectrum in the embodiment of the present application, a specific example is used to describe it in detail below. Figure 2 The plasma characteristic three-dimensional diagnostic device and plasma generating device based on emission spectrum are implemented, specifically including steps S1-S7: S1: multiple predetermined positions are set around the cavity, each predetermined position corresponds to a position signal, each position signal includes three sub-signals: a slider position sub-signal, a collimator height sub-signal and a collimator rotation angle sub-signal; wherein, the plasma emission spectrum corresponding to the three position signals (collimator rotation angles are -5 degrees, 0 degrees, 5 degrees) in each observation window; S2: A microwave plasma exciter ionizes the nitrogen introduced into the cylindrical cavity by the gas inlet device, and the generated plasma is focused above the base; Each time the processor sends a position signal, steps S3-S6 are executed: S3: The processor sends a position signal, and the slider adjusts the slider position, collimator height and rotation angle according to the position signal, that is, the collimator moves to a predetermined position corresponding to the position signal; S4: The collimator collects the emission spectrum of the plasma in parallel at a predetermined position and sends it to the detector; S5: The detector converts the emission spectrum signal into an electrical signal and sends the electrical signal to the processor; S6: The processor stores the electrical signal corresponding to the position signal and sends the next position signal; S7: The processor generates a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma based on the electrical signals corresponding to all the position signals and in combination with a pre-stored collision-radiation model of the plasma.

[0043] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A three-dimensional diagnostic device for plasma characteristics based on emission spectroscopy, characterized in that: include: A spectrometer, used to scan a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; A processor is used to obtain a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma according to a collision-radiation model of the plasma and the three-dimensional emission spectrum.

2. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 1, characterized in that: The spectrometer comprises a collimator and a detector connected by optical fiber; The collimator is used to collect the emission spectrum of the plasma in parallel at each of the predetermined positions, and transmit the collected emission spectrum signal to the detector through the optical fiber; The detector is used to convert the emission spectrum signal collected at each of the predetermined positions into an electrical signal and send the electrical signal to the processor.

3. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 2, characterized in that: Also includes: A slide rail, comprising an annular track and a slider; the slider is used to receive a position signal sent by the processor, and slide the carried object platform along the annular track based on the position signal; The loading platform is provided with a rotation axis, the rotation axis is used to receive the position signal sent by the processor, and adjust the height of the collimator and the rotation angle of the collimator in the normal plane of the rotation axis based on the position signal; The position signals correspond to the predetermined positions one by one, and each of the position signals includes a slider position sub-signal, a collimator height sub-signal, and a collimator rotation angle sub-signal.

4. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 3, characterized in that: Also includes: A plasma generating device, comprising a chamber and an air inlet device, an exciter and a base; The cavity is located within the inner track of the annular track; The base is located at the lower part of the cavity, and is used to focus the plasma above the base; The air inlet device is used to introduce external gas to be ionized into the cavity; The energizer is located in the cavity and is used to ionize the gas to be ionized to generate the plasma.

5. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 4, characterized in that: The cavity is a cylinder, and is provided with a plurality of observation windows at positions surrounding the plasma. The plurality of observation windows are evenly distributed along the circumferential direction and the height direction of the cavity, and each of the observation windows is used by the collimator to collect the emission spectrum of the plasma.

6. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 4, characterized in that: The gas to be ionized includes one or more of the following gases: hydrogen, methane, nitrogen, oxygen, argon, acetylene, borane and phosphine.

7. The plasma characteristic three-dimensional diagnostic device based on emission spectrum according to claim 4, characterized in that: The exciter includes one or more of the following exciters: a direct current electric field exciter, an alternating current electric field exciter and a high temperature heating exciter.

8. A three-dimensional diagnosis method of plasma characteristics based on emission spectroscopy, characterized in that: The method is performed by a plasma characteristic three-dimensional diagnosis device based on emission spectroscopy according to any one of claims 1 to 7, comprising: The spectrometer scans a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma; The processor obtains the collision-radiation model of the plasma and generates a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma in combination with the three-dimensional emission spectrum.

9. The three-dimensional diagnosis method of plasma characteristics based on emission spectrum according to claim 8, characterized in that: The spectrometer scans a plurality of predetermined positions around the plasma to obtain a three-dimensional emission spectrum of the plasma, including: Each of the predetermined locations performs the following operations: The processor sends a position signal to the slider and the rotation axis, and the slider and the rotation axis move the collimator of the spectrometer to the predetermined position corresponding to the position signal based on the position signal; The collimator collects the emission spectrum of the plasma in parallel through the observation window at the predetermined position, and transmits the collected emission spectrum signal to the detector through the optical fiber; The detector converts the emission spectrum signal of the predetermined position into an electrical signal; The position signal corresponds to the predetermined position one by one.

10. The three-dimensional diagnosis method of plasma characteristics based on emission spectrum according to claim 9, characterized in that: The processor acquires the collision-radiation model of the plasma and generates a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma in combination with the three-dimensional emission spectrum, including: The processor acquires the electrical signal corresponding to each of the predetermined positions and the collision-radiation model of the plasma; The processor obtains a three-dimensional temperature distribution and a three-dimensional concentration distribution of the plasma based on the electrical signals at all predetermined positions and the collision-radiation model.

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