Method and system for real-time monitoring of sputter yield of a material

Abstract

The application discloses a method and system for monitoring sputtering yield of material in real time, and belongs to the technical field of plasma and material interaction. The method comprises the following steps: generating and guiding a plasma beam to continuously bombard the surface of a material to be measured by using a plasma generating device; collecting the intensity data of a characteristic optical emission spectrum line of a specific atom generated by sputtering on the surface of the material to be measured in real time; collecting the saturation current data of plasma ions bombarding the surface of the material to be measured in real time; calculating the sputtering particle flow density of the specific atom in real time based on the intensity data of the characteristic optical emission spectrum line and the photon emission efficiency; calculating the plasma ion flux density in real time based on the saturation current data of the plasma ions and the effective collection area of a probe; and calculating and outputting the sputtering yield in real time according to the ratio of the sputtering particle flow density to the plasma ion flux density. The embodiment of the application can monitor the sputtering yield generated by the material in real time, and effectively improve the accuracy of the obtained sputtering yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plasma and material interaction, and particularly relates to a method and system for real-time monitoring of sputtering yield of material. BACKGROUND

[0002] In a magnetic confinement nuclear fusion device (such as ITER, CFETR), tungsten is a key plasma-facing material. In order to reduce the extreme heat load borne by the divertor, injecting neon gas for radiation cooling is a core scheme. However, this scheme, while protecting the material from heat load damage, introduces a new challenge: sputtering erosion of tungsten by neon plasma will directly affect the component lifetime and plasma purity. Therefore, accurately obtaining the sputtering yield data of tungsten in the neon plasma is a key to evaluating the feasibility of the technology, but the existing measurement methods have obvious bottlenecks.

[0003] At present, the experimental research methods for obtaining sputtering yield mainly include the weight loss method. The weight loss method has a large error because the sample needs to be taken out before and after irradiation and directly contacted with air, and the accuracy of the obtained sputtering yield is low. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a method and system for real-time monitoring of sputtering yield of material, which can monitor the sputtering yield generated by the material in real time and effectively improve the accuracy of the obtained sputtering yield.

[0005] To achieve the above-mentioned purpose, a first aspect of the embodiments of the present application provides a method for real-time monitoring of sputtering yield of material, comprising:

[0006] generating and guiding a plasma beam to continuously bombard the surface of a to-be-tested material by using a plasma generating device, so that the to-be-tested material is sputtered;

[0007] real-time collecting, by a spectrum collecting device, characteristic optical emission line intensity data of a specific atom generated by sputtering of the surface of the to-be-tested material;

[0008] real-time collecting, by a probe collecting device, saturated current data of plasma ions bombarding the surface of the to-be-tested material;

[0009] real-time calculating, based on the characteristic optical emission line intensity data and photon emission efficiency, a sputtering particle flow density of the specific atom;

[0010] real-time calculating, based on the saturated current data of the plasma ions and an effective collection area of the probe, a plasma ion flux density;

[0011] real-time calculating and outputting a sputtering yield according to a ratio of the sputtering particle flow density to the plasma ion flux density.

[0012] Compared with the prior art, the method for monitoring material sputtering yield in real time provided by the embodiment of the application has the beneficial effects that: first, a stable plasma beam is formed and guided by a plasma generating device to continuously bombard the surface of the material to be measured, thereby inducing sputtering; then, the spectral acquisition device synchronously captures the characteristic optical emission spectrum line intensity of the sputtered specific atoms in real time, and the probe acquisition device synchronously measures the ion saturation current of the bombarded material surface in real time; then, the collected optical signals and current signals are combined with the key physical parameter of photon emission efficiency and the effective collection area of the probe, respectively, and the two key physical quantities of sputtering particle flow density and plasma ion flux density are calculated in parallel and in real time; finally, the sputtering yield is dynamically output by calculating the ratio of the two. The method not only completely overcomes the disadvantages of the traditional loss-in-weight method, such as being unable to measure in real time and having large errors, but also realizes real-time monitoring of the sputtering transient characteristics, and significantly improves the accuracy and reliability of the sputtering yield measured by the method.

[0013] In some embodiments, the plasma is a neon plasma, and the material to be measured is a tungsten material.

[0014] In some embodiments, the characteristic optical emission spectrum line of the specific atom is a spectrum line of tungsten atoms at a wavelength of 400.8 nm.

[0015] In some embodiments, the characteristic optical emission spectrum line intensity data collected by the spectral acquisition device and the plasma ion saturation current data collected by the probe acquisition device have the same time stamp, so as to ensure that the data used for calculating the sputtering yield is derived from the plasma state at the same time.

[0016] To achieve the above-mentioned purpose, a second aspect of the embodiment of the application provides a system for monitoring material sputtering yield in real time, which applies the method for monitoring material sputtering yield in real time as described in the first aspect above, and the system comprises:

[0017] In some embodiments, the spectral acquisition device is optically connected to the surface of the material to be measured through an optical fiber and a collimating lens assembly.

[0018] In some embodiments, the spectral acquisition device comprises at least one first channel and at least one second channel, the optical receiving wavelength band of the first channel corresponds to the characteristic emission wavelength of the specific atom, and the optical receiving wavelength band of the second channel corresponds to the emission wavelength of the plasma component.

[0019] In some embodiments, the plasma generating device is a cascade arc plasma generator.

[0020] In some embodiments, the cascade arc plasma generator comprises a cathode, an anode, and a plurality of cascade segments arranged between the cathode and the anode.

[0021] In some embodiments, the periphery of the cascade arc plasma generator is provided with a solenoid coil generating an axial magnetic field. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a flow chart of a method for real-time monitoring of material sputtering yield provided by an embodiment of the present application;

[0023] Figure 2 is a structural schematic diagram of a system for real-time monitoring of material sputtering yield in an embodiment of the present application;

[0024] Figure 3 is another structural schematic diagram of a system for real-time monitoring of material sputtering yield in an embodiment of the present application.

[0025] The drawings are as follows: plasma generation device 100, cathode 101, cathode seat 102, anode 103, cascade sheet 104, insulating ceramic 105, neon gas inlet 106, magnetic field direction 107, plasma beam 200, material to be measured 300, water-cooled sample table 301, spectrum acquisition device 400, light propagation path 401, lens 402, photoelectric receiving probe 403, optical fiber 404, probe acquisition device 500, processing and calculation module 600. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0028] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0029] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] In the magnetic confinement nuclear fusion device, the plasma-facing wall material will have a series of interactions with the boundary plasma, and will be bombarded by strong particle flow and strong heat flow, affecting the service life of the divertor and the safe operation of the device. Tungsten has become the main candidate material for plasma-facing components (PFCs) due to its high melting point (3422℃), excellent thermal conductivity and low sputtering yield. The plasma-facing components in future fusion reactors (ITER and CFETR) must withstand an extreme heat load of more than 40 MW / m -2 , which is far beyond the bearing limit of the current divertor material (~15 MW / m -2 ).

[0031] To address this challenge, the radiation divertor technology has become a key solution by injecting impurity gas (such as neon) to enhance the radiation heat dissipation in the boundary region, thereby effectively reducing the heat load of the target plate. Among the many candidate impurity gases, neon is favored due to its low sputtering yield than argon, no tritium retention problem, and small disturbance to the core performance of the plasma. For example, experiments on the JT-60U device have confirmed that neon injection can effectively enhance the radiation power and improve energy confinement.

[0032] However, the introduction of neon impurities, while alleviating the heat load, also makes the physical environment of the divertor region more complex. The interaction of neon plasma with tungsten material, especially its sputtering erosion behavior on tungsten material, is directly related to the service life of the divertor and the safe operation of the fusion device. Therefore, accurately obtaining the sputtering yield data of tungsten under the action of neon plasma is crucial for evaluating material life, predicting the degree of plasma contamination, and optimizing the operation scheme of the divertor.

[0033] Currently, the experimental research methods for obtaining sputtering yield mainly include weight loss method and spectroscopy method, but both have significant limitations:

[0034] Weight loss method: This method requires the sample to be taken out and its mass difference to be measured accurately before and after plasma irradiation. Its main defects are: (1) unable to monitor in real time: only the average sputtering yield during the entire irradiation period can be obtained, completely unable to reflect the transient change characteristics of the sputtering process; (2) introducing secondary error: the sample inevitably contacts the atmosphere during the process of taking out, transporting and weighing, which may form an oxide film or contaminate impurities, introducing a large measurement error; (3) extremely low time resolution, unable to be used to study dynamic processes.

[0035] Spectroscopic method: This method calculates the sputtering particle flow by measuring the intensity of the characteristic spectrum line of the sputtered tungsten atoms. However, existing spectral measurement means are mostly isolated, non-continuous measurements, with large systematic errors.

[0036] Therefore, the embodiments of the present application provide a method and system for real-time monitoring of material sputtering yield, which can monitor the sputtering yield generated by the material in real time, and effectively improve the accuracy of the obtained sputtering yield.

[0037] Please refer to Figure 1 , Figure 1 is an optional flowchart of the method for real-time monitoring of material sputtering yield provided by the embodiments of the present application, Figure 1 The method in the flowchart can include but is not limited to steps S101 to S106.

[0038] Step S101: generating and guiding a plasma beam to continuously bombard the surface of the material to be measured by using a plasma generating device, so that the material to be measured is sputtered;

[0039] Step S102: real-time acquisition of the characteristic optical emission spectrum line intensity data of the specific atoms generated by sputtering on the surface of the material to be measured by a spectrum acquisition device;

[0040] Step S103: real-time acquisition of the plasma ion saturation current data bombarding the surface of the material to be measured by a probe acquisition device;

[0041] Step S104: real-time calculation of the sputtering particle flow density of the specific atoms based on the characteristic optical emission spectrum line intensity data and the photon emission efficiency;

[0042] Step S105: real-time calculation of the plasma ion flux density based on the plasma ion saturation current data and the effective collection area of the probe;

[0043] Step S106: real-time calculation and output of the sputtering yield according to the ratio of the sputtering particle flow density to the plasma ion flux density.

[0044] The steps S101 to S106 shown in the embodiments of the present application first form and guide a stable plasma beam to continuously bombard the surface of the material to be measured by using a plasma generating device, so as to induce sputtering; then, the characteristic optical emission spectrum line intensity of the sputtered specific atom is captured in real time by a spectrum acquisition device, while the ion saturation current of the bombarded material surface is measured in real time by a probe acquisition device; then, the collected optical signal and current signal are respectively combined with the key physical parameter of photon emission efficiency and the effective collection area of the probe, and the sputtering particle flow density and the plasma ion flux density are calculated in parallel and in real time; finally, the sputtering yield is dynamically output by calculating the ratio of the two. The method not only completely overcomes the disadvantages of the traditional loss-in-weight method, such as being unable to measure in real time and having large errors, but also realizes real-time monitoring of the sputtering transient characteristics, and significantly improves the accuracy and reliability of the sputtering yield measured by the synchronous correlation measurement of multi-dimensional signals and real-time calculation based on the physical model.

[0045] In step S101 of some embodiments, the plasma generating device refers to a device capable of generating and focusing a plasma beam, such as the cascade arc plasma generator in the present method. The cascade arc plasma generator works by high-voltage breakdown of working gas (such as neon) between the cathode and the anode, and uses multi-stage cascade sheets and axial magnetic field to form a stable and directional plasma beam. The material to be measured refers to the material whose sputtering resistance needs to be studied, such as the tungsten material in the present method. Sputtering refers to the physical process of bombarding the surface of a material with high-energy ions in a plasma, causing atoms on the surface to be ejected.

[0046] The plasma is a neon plasma, which is generated by the cascade arc plasma generator. The high-voltage breakdown of neon gas between the cathode and the anode forms an initial plasma, and the multi-stage cascade sheets further stabilize the arc. The axial magnetic field restrains the charged particles with Lorentz force, suppresses radial diffusion, and guides the formation of a directional neon plasma beam, which is transmitted to the surface of the tungsten sample. When the kinetic energy of neon ions exceeds the sputtering threshold of tungsten material, the sputtering of tungsten target atoms is triggered.

[0047] In step S102 of some embodiments, the spectrum acquisition device refers to a device for capturing and analyzing optical signals, such as a multi-channel spectrometer. The characteristic optical emission spectrum line of the specific atom is the spectrum line of tungsten atoms at 400.8 nm wavelength. The spectrum acquisition device receives the optical signal and separates the light through optical elements such as optical fibers and lenses. The characteristic optical emission spectrum line intensity refers to the intensity of the specific wavelength of light emitted by the sputtered atom (such as tungsten atom) after it leaves the material surface, such as the spectrum line of tungsten atom at 400.8 nm. The intensity is proportional to the number of sputtered atoms.

[0048] The detection light path of the multi-channel spectrometer is precisely aligned to the plasma- bombarded tungsten sample surface region, and the intensity of the tungsten atom 400.8 nm characteristic spectral line is monitored and recorded in real time. Specifically, the multi-channel spectrometer can be set to collect time intervals of 30s, and the intensity of the tungsten atom single characteristic peak spectral line (400.8nm) is extracted for the neon plasma generated by the cascade arc source.

[0049] In step S103 of some embodiments, the probe acquisition device refers to a sensor inserted into the plasma to measure its parameters, such as a fast-moving probe. Ion saturation current data can be the current collected when the probe applies a sufficiently negative bias, which is formed only by ion motion. The current size is directly proportional to the ion flux bombarding the sample surface. The fast-moving probe is inserted into the plasma beam, and the ion saturation current data is measured in real time near the sample surface. The probe can be radially scanned to obtain beam profile information, so as to determine the interaction area of the plasma and the sample.

[0050] Using the fast-moving probe, the step size is set to 2mm, the radial profile ion flux distribution of the neon plasma is collected, and the time interval is set to collect the ion flux at the center of the plasma beam every 1 minute.

[0051] In step S104 of some embodiments, the photon emission efficiency represents the average number of 400.8 nm wavelength photons that can be generated per sputtered tungsten atom. It is a function related to the electron temperature of the plasma, which needs to be calibrated in advance through experiments or theoretical models. Sputtering particle flux density : The number of sputtered atoms per unit area per unit time.

[0052] The processing and calculation module (such as a computer system) receives real-time characteristic optical emission spectral line intensity data from the spectrometer , and calls pre-stored parameters (determined according to the real-time measured electron temperature ) to calculate the sputtering particle flux density of tungsten atoms in real time through the formula .

[0053] In step S105 of some embodiments, the effective collection area (A) refers to the projection area of the probe perpendicular to the direction of the plasma beam magnetic field, which is a constant determined by the geometry of the probe. Ion flux density : The number of ions bombarding the unit sample surface per unit time.

[0054] The processing and calculation module receives real-time plasma ion saturation current data from the probe ), combined with the known effective collection area of ​​the probe ( ) and fundamental charge constant ( ), through formula Real-time calculation of plasma ion flux density ( ).

[0055] It should be noted that the characteristic optical emission line intensity data collected by the spectral acquisition device and the plasma ion saturation current data collected by the probe acquisition device have the same timestamp to ensure that the data used to calculate the sputtering yield originates from the plasma state at the same moment.

[0056] In step S106 of some embodiments, the sputtering yield ( ) is defined as the average number of material atoms sputtered per incident ion.

[0057] The processing and calculation module will calculate the sputtered particle flow density in real time. ) and plasma ion flux density ( Perform a ratio calculation, i.e., sputtering yield. Ultimately, this dynamically changing sputtering yield value and intermediate parameters are updated and output in real time on the display interface in the form of numbers or curves.

[0058] See Figure 2 This is a schematic diagram of a system for real-time monitoring of material sputtering yield provided in an embodiment of this application. The system for real-time monitoring of material sputtering yield utilizes the method described above, and includes:

[0059] Plasma generating device 100 is used to generate and guide plasma beam 200 to bombard the surface of material 300 under test;

[0060] The spectral acquisition device 400 has its optical path aligned with the surface of the material under test 300, and is used to acquire in real time the characteristic optical emission spectral intensity data of specific atoms generated by sputtering on the surface of the material under test 300.

[0061] The probe acquisition device 500 is set in the plasma beam 200 and is used to acquire the plasma ion saturation current data of the material being tested in real time.

[0062] The processing and calculation module 600, connected to the spectral acquisition device 400 and the probe acquisition device 500, is configured to: calculate the sputtered particle flux density of a specific atom in real time based on characteristic optical emission line intensity data and photon emission efficiency; calculate the plasma ion flux density in real time based on plasma ion saturation current data and the effective collection area of ​​the probe; and calculate and output the sputtering yield in real time according to the ratio of sputtered particle flux density to plasma ion flux density.

[0063] Specifically, referring to Figure 3 is another structural schematic diagram of a system for real-time monitoring of sputtering yield of a material provided by an embodiment of the present application. In the plasma generating device 100, the cathode seat 102 fixes the cathode 101, and forms a high-voltage electric field with the anode 103, breaks through the neon gas from the neon gas inlet 106 to generate an initial plasma, and the cascade sheet 104 constitutes a multi-stage arc structure to stabilize the initial plasma arc. The insulating ceramic 105 separates the cathode 101 and the anode 103 to avoid short circuit; the (neon) plasma beam 200 is transmitted in a directional manner under the constraint of the Lorentz force in the magnetic field direction 107, and acts on the material to be measured 300, which is placed on the water-cooled sample table 301; the characteristic optical signal emitted by the sputtered tungsten atoms is transmitted along the light propagation path 401, converged to the photoelectric receiving probe 403 through the lens 402, converted into a preliminary electrical signal, and then transmitted to the optical spectrum acquisition device 400 through the optical fiber 404 to output the optical spectrum signal, that is, the characteristic optical emission spectrum line intensity data is obtained; at the same time, the probe acquisition device 500 participates in signal acquisition to obtain the plasma ion saturation current data of the surface of the material to be measured; finally, all the spectrum / probe signals are transmitted to the processing and calculation module 600, and after processing, the sputtering particle flow density (tungsten atom flow density), plasma ion flux density and sputtering yield are calculated and displayed in real time.

[0064] Optionally, the spectrum acquisition device 400 is optically connected to the surface of the material to be measured 300 through the lens 402 and the optical fiber 404 assembly. The lens 402 can be a collimating lens.

[0065] Optionally, the spectrum acquisition device 400 includes at least one first channel and at least one second channel, the optical receiving waveband of the first channel corresponds to the characteristic emission wavelength of a specific atom, and the optical receiving waveband of the second channel corresponds to the emission wavelength of the plasma component.

[0066] Optionally, the plasma generating device 100 is a cascade arc plasma generator. The cascade arc plasma generator includes the cathode 101, the anode 103, and a plurality of cascade sheets 104 arranged between the cathode 101 and the anode 103. The cathode 101 is a tungsten cathode. The cascade arc plasma generator is provided with a solenoid coil for generating an axial magnetic field.

[0067] In a specific embodiment, the neon plasma is generated by the cascade arc plasma generator: the high-voltage between the cathode and the anode breaks through the neon gas to form an initial plasma, and the initial plasma is further arc-stabilized by the plurality of cascade sheets; the axial magnetic field restrains the charged particles by means of the Lorentz force, suppresses the radial diffusion of the charged particles, and then guides the formation of a directional neon plasma beam to be transmitted to the surface of the tungsten sample; when the kinetic energy of the neon ions exceeds the sputtering threshold of the tungsten material, the sputtering of the tungsten target atoms is triggered.

[0068] After fixing the tungsten sample on the target, the 8-channel spectrometer was used to align the center of the sample surface through the collimating lens, and then the spectrometer was connected to the computer system to eliminate noise. Since the light path is directly aligned with the sample surface, more accurate and real-time measurements of sputtered tungsten atoms can be achieved, with an error reduction of at least 5% compared to the weight loss method. The spectrometer used has 8 channels, which can simultaneously collect neon atom spectral lines and ion spectral lines in addition to collecting tungsten atom flow, for monitoring the fluctuations of the plasma during irradiation and the effects of tungsten sample sputtering on the plasma.

[0069] Further, the collection time interval of the spectrometer was set to 30 s, and the intensity variation of the tungsten atom single characteristic peak spectral line (400.8 nm) was extracted for the neon plasma generated by the cascade arc source plasma generator.

[0070] At the same time, the fast-moving probe was used to collect the ion flux distribution of the neon plasma radial profile with a step size of 2 mm, and the time interval was set to collect the ion flux at the center of the plasma beam every 1 minute.

[0071] Using multiple collection systems such as spectrometers and probes, real-time monitoring of changes in plasma and sample surface can be achieved. The collection time intervals of the above spectrometer and fast-moving probe can be adjusted to a maximum of one collection per second, and the required data can also be extracted, improving the time resolution of the measurement level.

[0072] The computer system uses the MATLAB program to calculate the tungsten atom flow, plasma half-width, ion flux average value, and relative error fluctuation in real time, where the tungsten atom flow and ion flux are given by equations (1) and (2), respectively:

[0073] (1) ;

[0074] where, is the tungsten atom flow on the sample surface; is the photon emission efficiency, which is a function of the electron temperature ; ; is the intensity of the tungsten atom characteristic spectral line (400.8 nm);

[0075] (2) ;

[0076] where, is the neon ion flux on the sample surface, is the saturated ion flux on the sample surface, is the charge constant, is the projection area of the probe perpendicular to the magnetic field direction.

[0077] Through the results of formula (1) and (2), the final sputtering yield is calculated and displayed in real time on the display interface of the computer system (computer) to monitor the condition of the tungsten sample during the neon plasma irradiation process. The sputtering yield (Y) is given by formula (3).

[0078] (3);

[0079] The embodiment of the present application proposes a system for capturing the intensity change of the tungsten atomic characteristic spectral line (400.8 nm) in real time through a spectrometer, thereby calculating the dynamic evolution law of the sputtered tungsten atomic flow on the sample surface. At the same time, the neon ion flux data measured by the fast-moving probe and the plasma action region diameter determined based on the radial profile half-width are integrated in the computer system to realize the dynamic visualization and accurate quantification of the tungsten atomic flow and the sputtering yield, greatly reducing the measurement error. The system solves the problem that the traditional method cannot reflect the sputtering transient characteristics in real time, significantly improves the measurement accuracy, and provides an efficient monitoring method for the research and engineering application of the interaction between the plasma and the tungsten material.

[0080] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when the program is executed, the processes of the above-mentioned embodiments can be included. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM), a random access memory (RAM), or the like.

[0081] The above describes the preferred embodiments of the present application. It should be noted that, for those of ordinary skill in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the protection scope of the present application.​

Claims

1. A method for real-time monitoring of material sputtering yield, characterized in that, include: A plasma beam is generated and guided by a plasma generator to continuously bombard the surface of the material under test, thereby causing the material under test to sputter. The intensity data of characteristic optical emission lines of specific atoms generated by sputtering on the surface of the material under test are collected in real time using a spectral acquisition device. The plasma ion saturation current data bombarding the surface of the material under test is collected in real time using a probe acquisition device. Based on the characteristic optical emission spectral intensity data and photon emission efficiency, the sputtered particle flux density of the specific atom is calculated in real time. Based on the plasma ion saturation current data and the effective collection area of ​​the probe, the plasma ion flux density is calculated in real time. The sputtering yield is calculated and output in real time based on the ratio of the sputtered particle flux density to the plasma ion flux density.

2. The method as described in claim 1, characterized in that, The plasma is neon plasma, and the material to be tested is tungsten material.

3. The method as described in claim 2, characterized in that, The characteristic optical emission spectral line of the specific atom is the spectral line of tungsten atom at a wavelength of 400.8 nm.

4. The method as described in claim 1, characterized in that, The characteristic optical emission line intensity data acquired by the spectral acquisition device and the plasma ion saturation current data acquired by the probe acquisition device have the same timestamp, to ensure that the data used to calculate the sputtering yield originates from the plasma state at the same moment.

5. A system for real-time monitoring of material sputtering yield, employing the method for real-time monitoring of material sputtering yield as described in any one of claims 1 to 4, characterized in that, The system includes: A plasma generating device is used to generate and guide a plasma beam to bombard the surface of the material under test. A spectral acquisition device, whose optical path is aligned with the surface of the material under test, is used to acquire in real time the intensity data of characteristic optical emission spectral lines of specific atoms generated by sputtering on the surface of the material under test. The probe acquisition device is set in the plasma beam to collect plasma ion saturation current data bombarding the surface of the material under test in real time. The processing and calculation module, connected to the spectral acquisition device and the probe acquisition device, is configured to: calculate the sputtered particle flux density of the specific atom in real time based on the characteristic optical emission line intensity data and photon emission efficiency; calculate the plasma ion flux density in real time based on the plasma ion saturation current data and the effective collection area of ​​the probe; and calculate and output the sputtering yield in real time according to the ratio of the sputtered particle flux density to the plasma ion flux density.

6. The system as described in claim 5, characterized in that, The spectral acquisition device is optically connected to the surface of the material to be tested via an optical fiber and a collimating lens assembly.

7. The system as described in claim 5, characterized in that, The spectral acquisition device includes at least one first channel and at least one second channel, wherein the optical receiving band of the first channel corresponds to the characteristic emission wavelength of the specific atom, and the optical receiving band of the second channel corresponds to the emission wavelength of the plasma component.

8. The system as described in claim 5, characterized in that, The plasma generating device is a cascaded arc plasma generator.

9. The system as described in claim 8, characterized in that, The cascaded arc plasma generator includes a cathode, an anode, and multiple cascaded plates disposed between the cathode and the anode.

10. The system as described in claim 8, characterized in that, The cascaded arc plasma generator is surrounded by a solenoid coil that generates an axial magnetic field.

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