Method and system for monitoring sputtering yield of material in real time

Abstract

The invention discloses a method and system for monitoring the sputtering yield of a material in real time, and belongs to the technical field of interaction of plasmas and materials. The method comprises the following steps: generating and guiding a plasma beam to continuously bombard the surface of a to-be-tested material by using a plasma generating device; collecting characteristic optical emission spectral line intensity data of specific atoms generated by sputtering on the surface of the to-be-detected material in real time; acquiring plasma ion saturation current data for bombarding the surface of the to-be-detected material in real time; based on the characteristic optical emission spectral line intensity data and the photon emission efficiency, the sputtering particle flow density of specific atoms is calculated in real time; calculating 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 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. According to the embodiment of the invention, the sputtering yield generated by the material can be monitored in real time, and the accuracy of the obtained sputtering yield is effectively improved.

Description

Technical Field

[0001] This application relates to the field of plasma-material interaction technology, and in particular to a method and system for real-time monitoring of material sputtering yield. Background Technology

[0002] In magnetic confinement fusion devices (such as ITER and CFETR), tungsten is a critical plasma-facing material. Radiation cooling using neon gas is a core solution to reduce the extreme thermal load on the divertor. However, while protecting the material from thermal damage, this approach introduces new challenges: the sputtering erosion of tungsten by neon plasma directly affects component lifespan and plasma purity. Therefore, accurately obtaining sputtering yield data for tungsten in neon plasma is crucial for evaluating the feasibility of this technology, but existing measurement methods have significant limitations.

[0003] Currently, the main experimental methods for obtaining sputtering yield include the weight loss method. However, the weight loss method requires removing the sample before and after irradiation and exposing it to air, which results in a large error and low accuracy of the sputtering yield obtained. Summary of the Invention

[0004] The purpose of this application is to 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.

[0005] To achieve the above objectives, a first aspect of this application provides a method for real-time monitoring of material sputtering yield, comprising: 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.

[0006] Compared with existing technologies, the method for real-time monitoring of material sputtering yield provided in this application has the following advantages: First, a stable plasma beam is formed and guided by a plasma generation device to continuously bombard the surface of the material under test, inducing sputtering. Next, the intensity of characteristic optical emission lines of specific sputtered atoms is captured in real time using a spectral acquisition device, while the ion saturation current of the bombarded material surface is measured in real time using a probe acquisition device. Then, the acquired optical and current signals are combined with the key physical parameter of photon emission efficiency and the effective collection area of ​​the probe to calculate the two key physical quantities, sputtered particle flux density and plasma ion flux density, in parallel and in real time. Finally, the sputtering yield is dynamically output by calculating the ratio of the two. This method not only completely overcomes the shortcomings of traditional weightlessness methods, which cannot be measured in real time and have large errors, and achieves real-time monitoring of the transient characteristics of sputtering, but also significantly improves the accuracy and reliability of the measured sputtering yield through synchronous correlation measurement of multi-dimensional signals and real-time calculation based on a physical model.

[0007] In some embodiments, the plasma is neon plasma and the material to be tested is tungsten.

[0008] In some embodiments, the characteristic optical emission spectral lines of the specific atom are the spectral lines of tungsten atoms at a wavelength of 400.8 nm.

[0009] In some embodiments, 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.

[0010] To achieve the above objectives, a second aspect of this application provides a system for real-time monitoring of material sputtering yield, which applies the method for real-time monitoring of material sputtering yield as described in the first aspect above. The system includes: In some embodiments, the spectral acquisition device is optically connected to the surface of the material to be measured via an optical fiber and a collimating lens assembly.

[0011] In some embodiments, 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.

[0012] In some embodiments, the plasma generating device is a cascaded arc plasma generator.

[0013] In some embodiments, the cascaded arc plasma generator includes a cathode, an anode, and multiple cascaded plates disposed between the cathode and the anode.

[0014] In some embodiments, a solenoid coil that generates an axial magnetic field is disposed around the periphery of the cascaded arc plasma generator. Attached Figure Description

[0015] Figure 1 This is a flowchart of a method for real-time monitoring of material sputtering yield provided in an embodiment of this application; Figure 2 This is a schematic diagram of a system for real-time monitoring of material sputtering yield in an embodiment of this application; Figure 3 This is another structural schematic diagram of a system for real-time monitoring of material sputtering yield in an embodiment of this application.

[0016] Reference numerals: Plasma generating device 100, cathode 101, cathode holder 102, anode 103, cascade plate 104, insulating ceramic 105, neon gas inlet 106, magnetic field direction 107, plasma beam 200, material to be tested 300, water-cooled sample stage 301, spectral 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 Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] In magnetically confined nuclear fusion devices, plasma-facing wall materials undergo a series of interactions with the boundary plasma, being bombarded by strong particle and heat fluxes, affecting the lifespan of divertors and the safe operation of the device. Tungsten, due to its high melting point (3422℃), excellent thermal conductivity, and low sputtering yield, has become a leading candidate material for plasma-facing components (PFCs). Future fusion reactors (ITER and CFETR) must withstand temperatures exceeding 40 MW / m³. -2 The extreme heat load far exceeds the current withstand limit of divertor materials (~15 MW / m²). -2 ).

[0022] To address this challenge, radiation divertor technology, by injecting impurity gases (such as neon) to enhance radiative heat dissipation in the boundary region and thus effectively reduce the thermal load on the target plate, has become a key solution. Among many candidate impurity gases, neon is favored due to its comprehensive advantages, including lower sputtering yield than argon, no tritium retention issues, and minimal disturbance to plasma core performance. For example, experiments on the JT-60U device have demonstrated that neon injection can effectively enhance radiative power and improve energy confinement.

[0023] However, while the introduction of neon impurities alleviates the heat load, it also complicates the physical environment of the divertor region. The interaction between neon plasma and tungsten materials, especially its sputtering erosion behavior on tungsten, directly affects the lifespan of the divertor and the operational safety of the fusion device. Therefore, accurately obtaining sputtering yield data of tungsten under neon plasma is crucial for assessing material lifespan, predicting plasma contamination levels, and optimizing divertor operation.

[0024] Currently, the main experimental methods for obtaining sputtering yield include the weight loss method and the spectroscopic method, but both have significant limitations: Weight loss method: This method requires the sample to be taken out before and after plasma irradiation and its mass difference to be measured accurately. Its main drawbacks are: (1) It cannot be monitored in real time: It can only obtain the average sputtering yield over the entire irradiation cycle and cannot reflect the transient changes in the sputtering process at all; (2) It introduces secondary errors: The sample will inevitably come into contact with the atmosphere during the removal, transport and weighing process, which may form an oxide film or be contaminated with impurities, introducing a large measurement error; (3) The time resolution is extremely low and it cannot be used to study dynamic processes.

[0025] Spectroscopic method: This method estimates the sputtered particle flow by measuring the intensity of the characteristic spectral lines of sputtered tungsten atoms. However, existing spectroscopic measurement methods are mostly isolated and discontinuous measurements with large systematic errors.

[0026] Based on this, embodiments of this 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.

[0027] Please see Figure 1 , Figure 1 This is an optional flowchart of a method for real-time monitoring of material sputtering yield provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S106.

[0028] Step S101: A plasma beam is generated and guided by a plasma generating device to continuously bombard the surface of the material under test, so as to cause sputtering of the material under test. Step S102: In real time, the intensity data of characteristic optical emission spectra of specific atoms generated by sputtering on the surface of the material under test are collected using a spectral acquisition device. Step S103: The plasma ion saturation current data bombarding the surface of the material under test is collected in real time using a probe acquisition device. Step S104: Based on the characteristic optical emission spectral intensity data and photon emission efficiency, calculate the sputtered particle flux density of a specific atom in real time; Step S105: 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. Step S106: Calculate and output the sputtering yield in real time based on the ratio of sputtered particle flux density to plasma ion flux density.

[0029] Steps S101 to S106 of this embodiment involve: first, using a plasma generation device to form and guide a stable plasma beam to continuously bombard the surface of the material under test, inducing sputtering; then, simultaneously capturing the intensity of characteristic optical emission lines of specific sputtered atoms in real time using a spectral acquisition device, and simultaneously measuring the ion saturation current of the bombarded material surface in real time using a probe acquisition device; then, combining the acquired optical and current signals with the key physical parameter of photon emission efficiency and the effective collection area of ​​the probe, respectively, to calculate the two key physical quantities, sputtered particle flux density and plasma ion flux density, in parallel and in real time; finally, by calculating the ratio of the two, the sputtering yield is dynamically output. This method not only completely overcomes the shortcomings of traditional weightlessness methods, such as the inability to measure in real time and large errors, and realizes real-time monitoring of sputtering transient characteristics, but also significantly improves the accuracy and reliability of the measured sputtering yield through synchronous correlation measurement of multi-dimensional signals and real-time calculation based on a physical model.

[0030] In step S101 of some embodiments, the plasma generating device refers to a device capable of generating and focusing a plasma beam, such as a cascaded arc plasma generator in this method. The cascaded arc plasma generator uses a high-voltage breakdown of the working gas (such as neon) between the cathode and anode, and utilizes multiple cascaded plates and an axial magnetic field to confine and form a stable, directional plasma beam. The material under test refers to the material whose sputtering resistance needs to be studied, such as tungsten in this method. Sputtering refers to the physical process in which high-energy ions in plasma bombard the surface of a material, causing surface atoms to be ejected.

[0031] The plasma is neon plasma, which is generated by a cascaded arc plasma generator. High voltage between the cathode and anode breaks down neon gas to form the initial plasma, and multiple cascaded plates further stabilize the arc; an axial magnetic field confines charged particles with Lorentz force, suppresses radial diffusion, and guides the formation of a directional neon plasma beam, which is transported to the surface of the tungsten sample; when the kinetic energy of the neon ions exceeds the sputtering threshold of the tungsten material, tungsten target atom sputtering is triggered.

[0032] In step S102 of some embodiments, the spectral acquisition device refers to a device used to capture and analyze optical signals, such as a multichannel spectrometer. The characteristic optical emission spectral line of a specific atom is the spectral line of tungsten atoms at a wavelength of 400.8 nm. The spectral acquisition device receives and disperses the optical signal through optical elements such as optical fibers and lenses. The intensity of the characteristic optical emission spectral line refers to the intensity of light of a specific wavelength (such as the spectral line of tungsten atoms at 400.8 nm) emitted by sputtered atoms (such as tungsten atoms) after detaching from the material surface. This intensity is proportional to the number of sputtered atoms.

[0033] The detection optical path of the multichannel spectrometer is precisely aligned with the surface region of the tungsten sample bombarded by plasma, and the intensity change of the 400.8 nm characteristic spectral line of tungsten atoms over time is monitored and recorded in real time. Specifically, the acquisition time interval of the multichannel spectrometer can be set to 30 seconds, and the intensity change of the single characteristic peak spectral line (400.8 nm) of tungsten atoms can be extracted for neon plasma generated by the cascaded arc source.

[0034] In step S103 of some embodiments, the probe acquisition device refers to a sensor, such as a fast-motion probe, inserted into the plasma to measure its parameters. Ion saturation current data can be the current collected solely from ion motion when a sufficiently negative bias is applied to the probe. This current magnitude is proportional to the ion flux bombarding the sample surface. The fast-motion probe is inserted into the plasma beam, and ion saturation current data is measured in real time near the sample surface. The probe can perform radial scanning to obtain beam profile information, thereby determining the interaction area between the plasma and the sample.

[0035] Using a fast-motion probe with a step size of 2 mm, the radial profile ion flux distribution of the neon plasma was collected, and a time interval was set to collect the ion flux at the center of the plasma beam every 1 minute.

[0036] In step S104 of some embodiments, the photon emission efficiency ( This indicates the average number of 400.8 nm wavelength photons generated per sputtered tungsten atom. It is related to the plasma electron temperature. Related functions ( Sputtered particle flux density ( ) needs to be calibrated beforehand through experiments or theoretical models. ): The number of sputtered atoms passing through a unit area per unit time.

[0037] The processing and computing module (such as a computer system) receives real-time characteristic optical emission line intensity data from the spectrometer. ), and call the pre-stored Parameters (based on real-time measured electronic temperature) (Confirmed), through formula The sputtered particle flux density of tungsten atoms is calculated in real time.

[0038] In step S105 of some embodiments, the effective collection area (A) refers to the projected area of ​​the probe perpendicular to the plasma beam magnetic field direction, and is a constant determined by the probe's geometry. Ion flux density ( ): The number of ions that bombard a unit sample surface per unit time.

[0039] 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 ( ).

[0040] 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.

[0041] In step S106 of some embodiments, the sputtering yield ( ) is defined as the average number of material atoms sputtered per incident ion.

[0042] 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.

[0043] 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: Plasma generating device 100 is used to generate and guide plasma beam 200 to bombard the surface of material 300 under test; 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. 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. 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.

[0044] Specifically, see Figure 3This is another structural schematic diagram of a system for real-time monitoring of material sputtering yield provided in this application embodiment. In the plasma generating device 100, the cathode holder 102 fixes the cathode 101, forming a high-voltage electric field with the anode 103, breaking down the neon gas introduced from the neon gas inlet 106 to generate initial plasma. The cascaded plates 104 form a multi-stage arc structure to stabilize the initial plasma arc. The insulating ceramic 105 isolates the cathode 101 and the anode 103 to avoid short circuits. The (neon) plasma beam 200 is directionally transmitted in the magnetic field direction 107 under the constraint of the Lorentz force, acting on the test material 300. The test material 300 (tungsten sample) is placed on the water-cooled sample stage 301. The characteristic emission of sputtered tungsten atoms... The optical signal is transmitted along the optical propagation path 401, converged by the lens 402 to the photoelectric receiving probe 403, converted into a preliminary electrical signal, and then transmitted by the optical fiber 404 to the spectral acquisition device 400 to output the spectral signal, thus obtaining the characteristic optical emission spectral line intensity data; at the same time, the probe acquisition device 500 participates in signal acquisition to obtain the plasma ion saturation current data on the surface of the material under test; finally, all spectral / probe signals are transmitted to the processing and calculation module 600, which processes and calculates the sputtering particle flux density (tungsten atom flux density), plasma ion flux density, and sputtering yield, and displays them in real time.

[0045] Optionally, the spectral acquisition device 400 is optically connected to the surface of the material to be measured 300 via an optical fiber 404 and a lens 402 assembly. The lens 402 can be a collimating lens.

[0046] Optionally, the spectral acquisition device 400 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 a specific atom, and the optical receiving band of the second channel corresponds to the emission wavelength of the plasma component.

[0047] Optionally, the plasma generating device 100 is a cascaded arc plasma generator. The cascaded arc plasma generator includes a cathode 101, an anode 103, and multiple cascaded plates 104 disposed between the cathode 101 and the anode 103. The cathode 101 is a tungsten cathode. A solenoid coil for generating an axial magnetic field is disposed around the periphery of the cascaded arc plasma generator.

[0048] In one specific embodiment, neon plasma is generated by a cascaded arc plasma generator: the high voltage between the cathode and anode breaks down the neon gas to form an initial plasma, which is further stabilized by multiple cascaded plates; the axial magnetic field confines the charged particles by the Lorentz force, suppressing their radial diffusion, and thus guiding the formation of a directional neon plasma beam, which is transported 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 tungsten target atoms is triggered.

[0049] After the tungsten sample is fixed on the target, an 8-channel spectrometer is used. The optical path is collimated through a lens and aligned to the exact center of the sample surface. The spectrometer is then connected to a computer system to eliminate noise. Because the optical path is directly aligned with the sample surface, more accurate and real-time measurements of sputtered tungsten atoms can be achieved, reducing the error by at least 5% compared to the weightlessness method. The spectrometer used has eight channels, which, in addition to acquiring the tungsten atomic stream, can simultaneously acquire neon atomic and ion spectra to monitor plasma fluctuations during irradiation and the impact of tungsten sample sputtering on the plasma.

[0050] Furthermore, the acquisition time interval of the spectrometer was set to 30 seconds, and the intensity change of the single characteristic peak spectral line (400.8 nm) of tungsten atoms was extracted for the neon plasma generated by the cascaded arc source plasma generator.

[0051] Meanwhile, using a fast-motion probe with a step size of 2 mm, the ion flux distribution of the radial profile of the neon plasma was collected, and the time interval was set to collect the ion flux at the center of the plasma beam once every 1 minute.

[0052] By utilizing multiple acquisition systems, including spectrometers and probes, changes in plasma and sample surfaces can be monitored simultaneously in real time. The acquisition time intervals of both the spectrometer and the fast-motion probe are adjustable, reaching up to once per second, while simultaneously extracting the required data, thus improving the measurement level of temporal resolution.

[0053] The computer system uses MATLAB to calculate the tungsten atomic flux, plasma half-width, average ion flux, and relative error fluctuation in real time. The tungsten atomic flux and ion flux are given by equations (1) and (2), respectively: (1); In the formula, The flow of tungsten atoms on the sample surface; Photon emission efficiency is the electron temperature. The function, ; The intensity of the characteristic spectral line (400.8 nm) of tungsten atoms; (2); In the formula, This represents the neon ion flux at the sample surface. The saturated ion flow at the sample surface. Where is the charge constant. This is the projected area of ​​the probe perpendicular to the magnetic field direction.

[0054] Based on the results of equations (1) and (2), the sputtering yield is finally calculated and displayed in real time on the computer system (PC) display interface, so as to monitor the status of the tungsten sample in real time during neon plasma irradiation. The sputtering yield ( The answer is given by equation (3).

[0055] (3); This application proposes a system for calculating the dynamic evolution of tungsten atom flow sputtered on a sample surface by real-time capture of the intensity changes of the characteristic spectral line (400.8 nm) of tungsten atoms using a spectrometer. Simultaneously, by combining neon ion flux data measured by a fast-motion probe and the diameter of the plasma interaction region determined based on the full width at half maximum (FWHM) of the radial profile, multi-dimensional parameters are integrated into a computer system. This enables dynamic visualization and precise quantification of tungsten atom flow and sputtering yield, significantly reducing measurement errors. This system solves the problem that traditional methods cannot reflect the transient characteristics of sputtering in real time, significantly improving measurement accuracy and providing an efficient monitoring method for the study and engineering applications of plasma-tungsten material interactions.

[0056] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0057] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this 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.

Images