A plasma mass spectrometry monitoring system and a monitoring method thereof

Abstract

This application provides a plasma mass spectrometry monitoring system and method, including a movable sampling module comprising a driving unit, a sampling tube, and a temperature control unit sleeved on the sampling tube. The sampling tube is used to extend into a process chamber to acquire plasma, and the temperature control unit is used to adjust the temperature of the sampling tube in real time. A mass spectrometry analysis module, located in the driving unit, is used to analyze and detect ionized ions to obtain an initial mass spectrometry signal. An ionization module, connected to the mass spectrometry analysis module, has one sidewall connected to one end of the sampling tube for ionizing plasma. A data processing module, electrically connected to the mass spectrometry analysis module, is used to acquire the initial mass spectrometry signal and calculate the final mass spectrometry signal. The plasma mass spectrometry monitoring system provided by this application can adjust the sampling position of the sampling tube as needed, thereby achieving high-precision spatial resolution detection of plasma components.

Description

Technical Field

[0001] This application relates to the field of plasma diagnostics and mass spectrometry analysis technology, and in particular to a plasma mass spectrometry monitoring system and its monitoring method. Background Technology

[0002] In the semiconductor manufacturing field, especially with the continuous shrinking of integrated circuit process nodes, extremely stringent requirements are placed on the uniformity and repeatability of processes such as plasma etching and deposition. The spatial distribution characteristics of plasma components, including radial and axial concentration gradients, directly determine the process results on the wafer surface. For example, in fluorocarbon plasma etching of silicon dioxide (SiO2) films, reactive debris such as CF2... + CF2 + CF3 + The spatial distribution differences of plasma directly affect the uniformity of etching rates and the conformality of sidewall profiles. If the spatial distribution of these plasma components cannot be accurately monitored, over-etching or etching residues can easily occur at wafer edges or in the center, severely reducing product yield. Furthermore, in argon or other inert gas plasmas, changes in the neutral plasma component density distribution caused by gas heating effects can indirectly affect electron temperature and energy distribution, thereby altering the stability of process parameters. Therefore, accurate characterization of these changes is also a crucial prerequisite for optimizing the process window.

[0003] Currently, plasma component detection technologies mainly rely on two categories: optical diagnostics and mass spectrometry. Optical methods, such as laser-induced fluorescence, can achieve non-invasive measurements and have a certain spatial resolution, but their systems are complex and costly, and they are usually only applicable to specific excited-state plasma components. Rayleigh scattering can be used to measure total particle number density, but it cannot distinguish between different mass numbers and has poor selectivity. Another widely used technique is traditional mass spectrometry, which typically collects plasma samples through sampling ports fixed to the chamber wall, introduces them into the ionization chamber via a differential pumping system, and analyzes the mass-to-charge ratio of neutral particles and ions through electron bombardment ionization.

[0004] However, existing traditional fixed mass spectrometry analysis techniques have the following significant drawbacks when applied to semiconductor mass production process monitoring: First, insufficient spatial resolution. Traditional mass spectrometry systems typically employ a single-point fixed sampling port design, limiting the sampling location to the chamber wall or a specific location. This only provides local information near the sampling point and cannot obtain plasma component concentration gradient information at different radial positions (e.g., from the wafer center to the edge) or axial positions (e.g., from the plasma sheath boundary to the bulk region) within the plasma without damaging the chamber structure. Second, the lack of a compensation mechanism for sampling tube temperature drift results in poor long-term monitoring stability. In actual plasma process environments, sampling tubes are often exposed to complex environments involving temperature fluctuations, plasma radiation heat, and chemical reaction heat. In traditional designs, temperature changes in the sampling tube can alter the adsorption / desorption coefficients of active plasma components on the tube wall, as well as cause drift in viscosity and conductivity during gas transport. These factors directly affect the representativeness and transmission efficiency of the sample, leading to long-term drift in the mass spectrometry signal. Due to the lack of an effective temperature compensation mechanism, traditional systems are unable to meet the requirements of semiconductor mass production lines for continuous and stable equipment operation and precise control of process parameters, often requiring frequent calibration and reducing production efficiency. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a plasma mass spectrometry monitoring system and monitoring method, which has high-precision spatial resolution detection and high signal stability, thereby improving the reliability of plasma component detection.

[0006] To address the aforementioned technical problems, in a first aspect, this application provides a plasma mass spectrometry monitoring system, comprising:

[0007] A movable sampling module includes a driving unit, a sampling tube, and a temperature control unit sleeved on the sampling tube. The sampling tube is used to extend into a process chamber to acquire plasma. The temperature control unit includes a controller, a temperature control tube, heating elements, and a temperature sensor. The temperature control tube is sleeved on the sampling tube. Several heating elements are disposed on the temperature control tube for independently adjusting the temperature on the temperature control tube. The temperature sensor is used to detect the temperature inside the sampling tube. The controller is electrically connected to both the heating elements and the temperature sensor. The controller is used to control and adjust the heating temperature of each heating element in real time, so that the temperature signal detected by the temperature sensor has an error within ±1℃ compared to the set target temperature.

[0008] A mass spectrometry analysis module, located in the drive unit, is used to analyze and detect ionized ions to obtain an initial mass spectrometry signal;

[0009] An ionization module is connected to the mass spectrometry analysis module, and one side wall of the ionization module is connected to one end of the sampling tube for ionizing plasma;

[0010] The data processing module is electrically connected to the mass spectrometry analysis module and is used to acquire the initial mass spectrometry signal and calculate the final mass spectrometry signal.

[0011] In operation, the drive unit drives the mass spectrometry analysis module, the ionization module, and the sampling tube to move, so that the sampling tube extends into a specific position within the process chamber.

[0012] In some embodiments of this application, the sampling tube includes a ceramic tube and a protective tube;

[0013] The ceramic tube has a sampling hole on its side wall near one end, and the other end of the ceramic tube is connected to the ionization module.

[0014] The temperature control unit is fitted onto the ceramic tube and covers the outer wall of the ceramic tube;

[0015] The protective tube is fitted onto the temperature control unit.

[0016] In some embodiments of this application, a heat-insulating material is filled between the temperature control unit and the protective tube; and / or,

[0017] The sampling tube is sealed to the process chamber by a flexible sealing sleeve.

[0018] In some embodiments of this application, the temperature control tube is sleeved on the ceramic tube, and the temperature control tube is divided into several temperature control segments along its axial direction. Each temperature control segment is provided with an installation groove and a cooling channel.

[0019] The temperature sensor is located in the mounting groove and is used to detect the temperature inside the ceramic tube;

[0020] The heating element is attached to the inner wall of the temperature control tube, and the heating element in each temperature control segment is independently temperature controlled;

[0021] The controller is also used to control the delivery of coolant to the cooling channel in order to adjust the temperature of the ceramic tube in real time.

[0022] In some embodiments of this application, the controller includes a data acquisition unit and a gradient temperature control unit;

[0023] The acquisition unit is electrically connected to the temperature sensor and is used to acquire the temperature signal detected by the temperature sensor.

[0024] The gradient temperature control unit is electrically connected to the acquisition unit. The gradient temperature control unit is used to set the target temperature, which includes a target axial temperature gradient. The gradient temperature control unit controls the power of the heating element in each temperature control segment so that the error between the temperature signal detected by the temperature sensor and the set target axial temperature gradient is within ±1℃.

[0025] In some embodiments of this application, the controller further includes a compensation unit;

[0026] The compensation unit is electrically connected to the acquisition unit and the data processing module. The compensation unit calculates the transmission efficiency correction factor η by acquiring the temperature signal and the parameters of the process gas in the process chamber. i The data processing module adjusts the transmission efficiency based on the transmission efficiency correction factor η. i The initial mass spectrometry signal is trimmed and compensated to obtain the final mass spectrometry signal I. i，corrected ;

[0027] η i The following calculation formula must be satisfied:

[0028] η i =exp ;

[0029] Where L is the length of the sampling tube, v is the airflow velocity in the process chamber, and k ads,i Let θ be the adsorption rate constant of plasma component i, and θ be the effective adsorption site coverage.

[0030] I i，corrected The following calculation formula must be satisfied:

[0031] I i,corrected =I i,raw / η i ;

[0032] Among them, I i，raw This is the initial mass spectrum signal.

[0033] In some embodiments of this application, the ionization module includes an ionization cavity and a dual-mode adjustable ionization source;

[0034] The ionization cavity is connected to the sampling module;

[0035] The dual-mode adjustable ionization source is located inside the ionization cavity. The dual-mode adjustable ionization source includes an electron bombardment ionization unit and a dielectric barrier discharge ionization unit. The electron bombardment ionization unit and the dielectric barrier discharge ionization unit can be started individually or all of them to achieve three ionization working modes.

[0036] In some embodiments of this application, a vacuum pump is also included;

[0037] The ionization chamber is equipped with a partition, which divides the ionization chamber into a first chamber and a second chamber. A flow-limiting hole is formed on the partition, which connects the first chamber and the second chamber. An air inlet and a suction hole are formed on the side wall of the first chamber.

[0038] The dielectric barrier discharge ionization unit is disposed in the first chamber, and the first chamber is connected to the sampling tube;

[0039] The air inlet is used to connect to the air supply unit;

[0040] The vacuum pump is connected to the suction port;

[0041] The electron bombardment ionization unit is located in the second chamber.

[0042] In some embodiments of this application, the mass spectrometry analysis module includes a mass spectrometry analysis cavity, an ion optical system, a mass analyzer, a detection unit, and a vacuum system;

[0043] The mass spectrometry analysis chamber is connected to the ionization chamber;

[0044] The ion optical system is located on one side wall of the mass spectrometry analysis cavity and extends into the ionization cavity, and is used to focus the ion beam and inject it into the mass analyzer.

[0045] The mass analyzer is located inside the mass spectrometry analysis cavity and close to the ion optical system, and is used to analyze the ion beam;

[0046] The detection unit is located inside the mass spectrometry analysis cavity and close to the mass analyzer, and is used to detect ions;

[0047] The vacuum system is connected to the mass spectrometry analysis chamber and is used to adjust the vacuum environment inside the mass spectrometry analysis chamber.

[0048] In a second aspect, embodiments of this application provide a plasma mass spectrometry monitoring method, employing the aforementioned plasma mass spectrometry monitoring system, the method comprising:

[0049] S100: Control the movable sampling module to extend the sampling tube into a predetermined position within the process chamber to obtain plasma at a specific location within the process chamber;

[0050] S200: Set the target axial temperature gradient on the temperature control unit and control the temperature control unit to adjust the temperature inside the sampling tube in real time;

[0051] S300: Start the ionization module to ionize the plasma;

[0052] S400: Start the mass spectrometry analysis module to create a vacuum environment inside the mass spectrometry analysis module, and analyze and detect the ionized ions to obtain the initial mass spectrometry signal;

[0053] S500: The data processing module acquires the initial mass spectrum signal and calculates the final mass spectrum signal;

[0054] S600: Steps S100-S500 are used to sample and analyze plasma at different locations within the process cavity to obtain spatial distribution information of the plasma.

[0055] In some embodiments of this application, setting a target axial temperature gradient on the temperature control unit and controlling the temperature control unit to adjust the temperature inside the sampling tube in real time includes:

[0056] The temperature control tube within the temperature control unit is sequentially divided into several temperature control segments;

[0057] Based on the set target axial temperature gradient, the temperature of each temperature control segment is controlled to make the temperature in the sampling tube gradient distribution between 180℃ and 80℃.

[0058] The temperature control unit adjusts the temperature in the temperature control section in real time so that the error between the actual temperature in the sampling tube and the set target temperature is within ±1℃.

[0059] In some embodiments of this application, the ionization activation module is used to ionize the plasma, including:

[0060] The ionization module has three ionization operating modes:

[0061] Turn off the electron bombardment ionization unit in the ionization module and turn on the dielectric barrier discharge ionization unit in the ionization module;

[0062] Turn on the electron bombardment ionization unit and turn off the dielectric barrier discharge ionization unit;

[0063] First, activate the dielectric barrier discharge ionization unit, and then activate the electron bombardment ionization unit.

[0064] The beneficial effects of the plasma mass spectrometry monitoring system and method provided in this application are as follows:

[0065] 1. This application features highly flexible spatially resolved sampling and precise axial temperature gradient control. A drive unit enables millimeter-level precision axial displacement adjustment of the sampling tube within the process chamber, allowing for non-destructive acquisition of the spatial distribution information of plasma from the boundary layer to the center region. Based on this, a decreasing temperature gradient is established along the sampling tube axis from the process chamber side to the mass spectrometry analysis chamber side, achieving precise matching between the sample acquisition location and the temperature of the transport path. Temperature gradient parameters are optimized according to the sample characteristics at different sampling locations (boundary region / center region). Boundary region samples are susceptible to wall cooling; enhanced heating in the high-temperature section prevents condensation. Center region samples have high free radical concentrations; precisely maintaining the gradient protects active species. Therefore, while acquiring spatial distribution information, the system ensures that samples at each location are transported in optimal thermal condition, fundamentally eliminating sample distortion and signal drift caused by changes in sampling location, thus achieving high-precision spatially resolved detection.

[0066] 2. This application employs a dual-mode adjustable ionization source design, achieving three flexibly adjustable ionization modes: pure dielectric barrier discharge (DBD) soft ionization, pure electron impact ionization (EI) standard ionization, and a DBD / EI synergistic mode. In practical applications, engineers can switch the corresponding ionization mode according to the specific type and composition characteristics of the plasma to be detected, improving the adaptability to different plasmas and compositions and the applicability of the product.

[0067] 3. The plasma mass spectrometry monitoring system provided in this application adopts a modular design, which simplifies the maintenance process and enables rapid replacement and process adaptation of each module. Attached Figure Description

[0068] Figure 1 A schematic diagram of the structure of the plasma mass spectrometry monitoring system provided in this application;

[0069] Figure 2 This is a schematic diagram of the sampling tube provided in the embodiments of this application;

[0070] Figure 3 This is a schematic diagram of the ionization module provided in the embodiments of this application;

[0071] Figure 4 A flowchart of the plasma mass spectrometry monitoring method provided in this application.

[0072] Figure label:

[0073] The system includes: a movable sampling module 1, a drive unit 11, a sampling tube 12, a ceramic tube 121, a sampling hole 1211, a protective tube 122, a temperature control unit 13, a controller 131, a temperature control tube 132, a heating element 133, a temperature sensor 134, a flexible sealing sleeve 14, a mass spectrometry analysis module 2, a mass spectrometry analysis chamber 21, an ion optical system 22, a mass analyzer 23, a detection unit 24, a vacuum system 25, an ionization module 3, an ionization chamber 31, a first chamber 311, a second chamber 312, a dual-mode adjustable ionization source 32, an electron bombardment ionization unit 321, a dielectric barrier discharge ionization unit 322, a vacuum pump 33, a partition 34, a gas supply unit 35, a data processing module 4, and a process chamber 5. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this application pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects. Unless otherwise specified, the term "connection" as used herein can refer to a direct connection or an indirect connection, i.e., a connection through an intermediate object.

[0075] Furthermore, it should be understood that the orientations or positional relationships indicated by terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" in this document are based on the orientations or positional relationships shown in the accompanying drawings and 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, and therefore should not be construed as a limitation on this application. The terms "first" and "second" in this document are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0076] To address the problems existing in the prior art, embodiments of this application provide a plasma mass spectrometry monitoring system, with reference to... Figures 1 to 3As shown, the system includes a movable sampling module 1, a mass spectrometry analysis module 2, an ionization module 3, and a data processing module 4. The movable sampling module 1 includes a driving unit 11, a sampling tube 12, and a temperature control unit 13 mounted on the sampling tube 12. The sampling tube 12, controlled by the driving unit 11, is used to extend into the process chamber 5 to acquire plasma. The temperature control unit 13 is used to adjust the temperature of the sampling tube 12 in real time. The mass spectrometry analysis module 2 is mounted on the driving unit 11 and is used to analyze and detect the ionized ions to obtain an initial mass spectrometry signal. The ionization module 3 is connected to the mass spectrometry analysis module 2, and one side wall of the ionization module 3 is connected to one end of the sampling tube 12 for ionizing the plasma. The data processing module 4 is electrically connected to the mass spectrometry analysis module 2 and is used to acquire the initial mass spectrometry signal and calculate the final mass spectrometry signal.

[0077] In operation, the drive unit 11 drives the mass spectrometry analysis module 2, the ionization module 3, and the sampling tube 12 to move, so that the sampling tube 12 extends into a specific position within the process chamber 5.

[0078] In this embodiment, the driving unit 11 enables millimeter-level axial displacement adjustment of the sampling tube 12 within the process chamber 5, allowing for non-destructive acquisition of the spatial distribution information of plasma from the boundary layer to the central region. Based on this, the temperature control unit 13 controls the internal temperature of the sampling tube 12, establishing a decreasing temperature gradient along the axial direction of the sampling tube 12 from the process chamber 5 side to the mass spectrometry analysis module 2 side, achieving precise matching between the sample acquisition location and the temperature along the transmission path. The temperature gradient parameters are optimized according to the sample characteristics at different sampling locations (boundary region / central region). Because samples in the boundary region are susceptible to wall cooling, enhanced heating in the high-temperature section prevents condensation; samples in the central region have high free radical concentrations, and precisely maintaining the gradient protects active species. Therefore, through the combined action of the driving unit 11 and the temperature control unit 13, the system ensures that samples at each location are transmitted in optimal thermal condition while acquiring spatial distribution information, fundamentally eliminating sample distortion and signal drift caused by changes in sampling location, and achieving long-term stable, high-precision spatial resolution measurement of plasma components.

[0079] In some embodiments, the drive unit 11 includes a driver and a mobile platform, the driver being connected to the mobile platform, and the mass spectrometry analysis module 2 being disposed on the mobile platform.

[0080] In this embodiment, the driver is a non-magnetic piezoelectric ceramic linear motor to ensure the positional accuracy of the sampling tube 12 extending into the process cavity 5.

[0081] In some embodiments, the sampling tube 12 includes a ceramic tube 121 and a protective tube 122. The ceramic tube 121 has a sampling hole 1211 on its sidewall near one end, and the other end of the ceramic tube 121 is connected to the ionization module 3. The diameter of the sampling hole 1211 can be set in the range of 0.001-0.005 inches. The sampling hole 1211 is used to acquire plasma from the process chamber 5 and then transmit it to the ionization module 3 through the channel of the ceramic tube 121. The temperature control unit 13 is sleeved on the ceramic tube 121 and covers the outer wall of the ceramic tube 121. The protective tube 122 is sleeved on the temperature control unit 13.

[0082] In this embodiment, the ceramic tube 121 is a tubular structure made of ceramic material, and its inner diameter is 0.3-0.8 mm. The chemical inertness of the ceramic tube 121 ensures that no side reactions occur in highly reactive plasmas such as fluorocarbon plasmas, guaranteeing the authenticity of the sampled gas. Furthermore, the electrical insulation properties of the ceramic tube 121 prevent the sampling tube 12 from becoming a floating electrode inserted into the plasma, minimizing disturbance to the original field distribution.

[0083] More importantly, the ceramic tube 121, with its moderate thermal conductivity and precision-polished surface, provides a material basis for accurately constructing axial temperature gradients and reducing wall adsorption sites.

[0084] In some embodiments, the space between the temperature control unit 13 and the protective tube 122 is filled with heat insulation material.

[0085] In this embodiment, the protective tube 122 mainly protects the ceramic tube 121 and the temperature control unit 13. By filling the space between the protective tube 122 and the temperature control unit 13 with heat insulation material, the sampling tube 12 can simultaneously have the functions of corrosion prevention, thermal isolation and mechanical protection.

[0086] In some embodiments, the sampling tube 12 and the process chamber 5 are sealed together by a flexible sealing sleeve 14.

[0087] In this embodiment, the sampling tube 12 is sealed to the process cavity 5 by using a flexible sealing sleeve 14, so that the sampling tube 12 can be moved to adjust the sampling position while ensuring the airtightness of the process cavity 5.

[0088] In some embodiments, the temperature control unit 13 includes a controller 131, a temperature control tube 132, a heating element 133, and a temperature sensor 134. The temperature control tube 132 is sleeved on the ceramic tube 121 and is divided into several independent temperature control sections along its axial direction. Each temperature control section has an installation groove and a cooling channel. The temperature sensor 134 is located in the installation groove and is used to detect the temperature changes within the ceramic tube 121 in real time and accurately, converting the detected temperature signal into an electrical signal for transmission. The heating element 133 is attached to the inner wall of the temperature control tube 132, and the heating element 133 in each temperature control section is independently temperature-controlled. The controller 131 is electrically connected to both the heating element 133 and the temperature sensor 134, and is used to control the heating temperature of the heating element 133 and control the delivery of coolant to the cooling channel for real-time temperature adjustment of the ceramic tube 121.

[0089] In this embodiment, the temperature control tube 132 is tightly wrapped around the outside of the ceramic tube 121 in a sleeve manner, providing a stable basic structure for temperature regulation throughout the ceramic tube 121. The heating element 133 is tightly attached to the inner wall of the temperature control tube 132, and each heating element 133 in each temperature control segment has an independent temperature control function. This means that each temperature control segment can individually adjust the heating power of the heating element 133 according to the actual temperature requirements of different locations within the ceramic tube 121, thereby achieving more precise temperature control. The controller 131 has powerful data processing and control capabilities, and can receive the temperature signal from the temperature sensor 134 in real time, and analyze and judge it according to preset temperature parameters. Then, the controller 131 will accurately control the heating temperature of the heating element 133 and control the delivery of coolant to the cooling channel based on the analysis results. Through the temperature regulation method combining heating and cooling, it ensures that the temperature inside the ceramic tube 121 is always maintained within the set range.

[0090] In some embodiments, the temperature sensor 134 can be directly attached to the inner wall of the ceramic tube 121 to achieve in-situ, transient, and high-precision measurement of the gas-solid interface temperature.

[0091] In some embodiments, the controller 131 includes a data acquisition unit and a gradient temperature control unit. The data acquisition unit is electrically connected to the temperature sensor 134 and is used to acquire the temperature signal detected by the temperature sensor 134. The gradient temperature control unit is electrically connected to the data acquisition unit and is used to set a target axial temperature gradient and control the power of the heating element 133 in each temperature control segment, so that the error between the temperature signal detected by the temperature sensor 134 and the set target axial temperature gradient is within ±1℃.

[0092] In this embodiment, the acquisition unit can synchronously acquire the temperature signal of the temperature sensor 134 array on the sampling tube 12 at high speed, and reconstruct the axial temperature distribution profile T by interpolation. profile(x) The acquisition delay is ≤50ms to ensure the timeliness and accuracy of temperature signal acquisition. The gradient temperature control unit allows the operator to preset the target axial temperature gradient and then independently and dynamically adjust the power of the heating element 133 on each temperature control segment to stabilize the temperature gradient of the inner wall of the ceramic tube 121 within an error range of ±1℃.

[0093] For example, when the plasma type in the process chamber 5 is Ar, the target axial temperature gradient is set to a linear gradient of 100-80℃. When the plasma type in the process chamber 5 is C2F6, the target axial temperature gradient is set to a linear gradient of 180-80℃.

[0094] In some embodiments, the controller 131 further includes a compensation unit. The compensation unit is electrically connected to the acquisition unit and the data processing module 4. The compensation unit calculates the transmission efficiency correction factor η by acquiring the temperature signal and the parameters of the process gas in the process chamber 5. i The data processing module 4 adjusts the transmission efficiency based on the transmission efficiency correction factor η. i The initial mass spectrometry signal is trimmed and compensated to obtain the final mass spectrometry signal I. i，corrected .

[0095] η i The following calculation formula must be satisfied:

[0096] η i =exp ;

[0097] Where L is the length of sampling tube 12, v is the airflow velocity in process chamber 5, and k ads,i Let θ be the adsorption rate constant of plasma component i, and θ be the effective adsorption site coverage.

[0098] Final mass spectrum signal I i，corrected The following calculation formula must be satisfied:

[0099] I i,corrected =I i,raw / η i ;

[0100] Among them, I i，raw This is the initial mass spectrum signal.

[0101] It should be noted that temperature changes can significantly affect the transmission of mass spectrometry signals during actual measurements. For example, increased temperature may intensify the thermal motion of gas molecules, increasing the collision frequency of ions during transmission and thus affecting ion transmission efficiency. Consequently, the initial mass spectrometry signal may not accurately reflect the actual gas conditions within process chamber 5. In this embodiment, the compensation unit acquires the temperature signal within process chamber 5 and, in conjunction with the parameters of the process gas within process chamber 5, calculates a transmission efficiency correction factor ηi. This factor is then used to adjust and compensate the initial mass spectrometry signal, effectively eliminating the interference of temperature factors on the measurement results and obtaining a more accurate final mass spectrometry signal I. i,corrected This improves measurement accuracy. Specifically, the temperature signal within process chamber 5 is directly measured using kJ / kL. ads,i .

[0102] In some embodiments, the ionization module 3 includes an ionization cavity 31 and a dual-mode adjustable ionization source 32. The ionization cavity 31 is connected to the sampling module. The dual-mode adjustable ionization source 32 is disposed within the ionization cavity 31. The dual-mode adjustable ionization source 32 includes an electron bombardment ionization unit 321 and a dielectric barrier discharge ionization unit 322. The electron bombardment ionization unit 321 and the dielectric barrier discharge ionization unit 322 can be activated individually or both, realizing three flexibly adjustable ionization modes: pure dielectric barrier discharge (DBD) soft ionization, pure electron impact ionization (EI) standard ionization, and a DBD / EI synergistic mode. In practical applications, engineers can switch the corresponding ionization mode according to the specific type and composition characteristics of the plasma to be detected, improving the adaptability to different plasmas and compositions and the applicability of the product.

[0103] Different plasma components possess different physical and chemical properties, thus requiring different ionization methods. For instance, the electron energy of the electron bombardment ionization unit 321 can be continuously adjusted within the range of 10-105 eV. By bombarding plasma component molecules with high-energy electrons, it ionizes them, making it suitable for the ionization of most organic compounds and some inorganic compounds. In particular, it can generate abundant fragment ion information for molecules with stable structures, which is helpful for detailed analysis of the plasma component structure. The dielectric barrier discharge ionization unit 322, as an auxiliary ionization source, applies a 3000-5000V pulse voltage (frequency 10-50kHz) and uses the plasma generated by dielectric barrier discharge to ionize the plasma components. This is more suitable for ionizing some non-volatile and thermally unstable samples.

[0104] The dual-mode adjustable ionization source 32 provided in this embodiment allows the electron bombardment ionization unit 321 or the dielectric barrier discharge ionization unit 322 to be activated individually, or all of them to be activated. It can flexibly select the appropriate ionization mode according to the characteristics of the sample, which greatly improves the flexibility of analysis.

[0105] In some embodiments, the plasma mass spectrometry monitoring system further includes a vacuum pump 33. A partition 34 is provided within the ionization chamber 31, dividing the ionization chamber 31 into a first chamber 311 and a second chamber 312. A flow-limiting orifice is formed on the partition 34, connecting the first chamber 311 and the second chamber 312. An air inlet and a suction port are formed on the side wall of the first chamber 311. A dielectric barrier discharge ionization unit 322 is located in the first chamber 311, and the first chamber 311 is connected to the sampling tube 12. The air inlet is used to connect to a gas supply unit 35. The vacuum pump 33 is connected to the suction port. The electron bombardment ionization unit 321 is located in the second chamber 312.

[0106] In this embodiment, the ionization cavity 31 is divided into a first chamber 311 and a second chamber 312 by the partition 34, and the dielectric barrier discharge ionization unit 322 is disposed in the first chamber 311 and the electron bombardment ionization unit 321 is disposed in the second chamber 312, so as to realize the switching of the three ionization working modes of the ionization module 3.

[0107] Further, the mass spectrometry analysis module 2 includes a mass spectrometry analysis cavity 21, an ion optical system 22, a mass analyzer 23, a detection unit 24, and a vacuum system 25. The mass spectrometry analysis cavity 21 is connected to the ionization cavity 31; the ion optical system 22 is disposed on one side wall of the mass spectrometry analysis cavity 21 and extends into the ionization cavity 31, used to focus the ion beam and inject it into the mass analyzer 23; the mass analyzer 23 is disposed within the mass spectrometry analysis cavity 21 and close to the ion optical system 22, used to analyze the ion beam; the detection unit 24 is disposed within the mass spectrometry analysis cavity 21 and close to the mass analyzer 23, used to detect ions; the vacuum system 25 is connected to the mass spectrometry analysis cavity 21 and used to adjust the vacuum environment within the mass spectrometry analysis cavity 21.

[0108] In this embodiment, the ion optical system 22 is an electrostatic lens group with an adjustable voltage range of -100V to -200V, achieving optimized ion focusing and transmission efficiency. The mass analyzer 23 is a quadrupole mass analyzer with a mass range of 1-200 amu, a resolution of 1 amu, a scan speed of 50 amu / s, and supports dynamic switching between full scan and selected ion monitoring modes. The detection unit 24 adopts a dual detector structure of Faraday cup (FC) and electron multiplier (CDEM), with a minimum detectable partial voltage of 1.0E-13 Torr. The vacuum system 25 uses a combination of molecular pump and diaphragm pump to ensure that the vacuum degree in the mass spectrometry analysis chamber 21 is ≤5×10⁻⁶. -7 Torr.

[0109] In yet another embodiment of the present invention, a plasma mass spectrometry monitoring method is provided, which uses the plasma mass spectrometry monitoring system provided in the above embodiments for monitoring, with reference to... Figures 1 to 4 As shown, the monitoring method includes:

[0110] S100: Control the movable sampling module 1 so that the sampling tube 12 extends into a predetermined position in the process cavity 5 to obtain plasma at a specific position in the process cavity 5.

[0111] In this step, engineers can precisely and flexibly adjust the sampling position of the sampling tube 12 into the process chamber 5 according to actual monitoring needs, so as to obtain representative plasma samples.

[0112] S200: Set a target axial temperature gradient on the temperature control unit 13 and control the temperature control unit 13 to adjust the temperature inside the sampling tube 12 in real time.

[0113] In this step, the temperature control unit 13 is divided into several independent temperature control segments by the temperature control tube 132. Based on the set target axial temperature gradient, the temperature in each temperature control segment is controlled to ensure that the temperature inside the sampling tube 12 exhibits a gradient distribution between 180℃ and 80℃, specifically with higher temperatures closer to the process chamber 5. Furthermore, during this process, the temperature control unit 13 adjusts the temperature in the temperature control segments in real time through the heating element 133 and the cooling channel, ensuring that the error between the actual temperature inside the sampling tube 12 and the set target temperature is within ±1℃.

[0114] For example, when the plasma type is Ar or C2F6, the target axial temperature gradient is set to 100℃-80℃. When the plasma type is fluorocarbon plasma, the target axial temperature gradient is 180℃-80℃.

[0115] S300: Start ionization module 3, used to ionize the plasma.

[0116] In this step, since the ionization module 3 has three ionization working modes, the ionization working mode can be switched according to the actual situation during actual testing.

[0117] For example, when detecting fragile free radicals, the electron bombardment ionization unit 321 in the ionization module 3 can be turned off, and the dielectric barrier discharge ionization unit 322 in the ionization module 3 can be turned on.

[0118] When targeting non-ionic neutral molecules, the electron bombardment ionization unit 321 is activated, and the dielectric barrier discharge ionization unit 322 is deactivated.

[0119] When it is necessary to reveal the transformation relationship between precursor free radicals and final products, the dielectric barrier discharge ionization unit 322 is turned on in advance to pre-ionize the precursor free radicals, and then the electron bombardment ionization unit 321 is turned on for secondary ionization.

[0120] S400: Start the mass spectrometry analysis module 2 to create a vacuum environment inside the mass spectrometry analysis module 2, and analyze and detect the ionized ions to obtain the initial mass spectrometry signal.

[0121] S500: The data processing module 4 acquires the initial mass spectrum signal and calculates the final mass spectrum signal.

[0122] S600: The above steps are used to sample and analyze plasma at different locations within the process cavity 5 to obtain spatial distribution information of the plasma.

[0123] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of this application should be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A plasma mass spectrometry monitoring system, characterized in that, include: A movable sampling module includes a driving unit, a sampling tube, and a temperature control unit sleeved on the sampling tube. The sampling tube is used to extend into the process chamber to obtain plasma, and the temperature control unit is used to adjust the temperature of the sampling tube in real time. A mass spectrometry analysis module, located in the drive unit, is used to analyze and detect ionized ions to obtain an initial mass spectrometry signal; An ionization module is connected to the mass spectrometry analysis module, and one side wall of the ionization module is connected to one end of the sampling tube for ionizing plasma; The data processing module, electrically connected to the mass spectrometry analysis module, is used to acquire the initial mass spectrometry signal and calculate the final mass spectrometry signal. In operation, the driving unit drives the mass spectrometry analysis module, the ionization module and the sampling tube to move, so that the sampling tube extends into a specific position in the process chamber, the specific position including the position between the boundary layer and the central region in the process chamber. The temperature control unit includes a controller, and the controller includes a data acquisition unit and a compensation unit; The acquisition unit is electrically connected to the temperature sensor and is used to acquire the temperature signal detected by the temperature sensor. The compensation unit is electrically connected with the acquisition unit and the data processing module, and the compensation unit calculates a transmission efficiency correction factor η by acquiring the temperature signal and parameters of the process gas in the process cavity i The data processing module corrects and compensates the initial mass spectrum signal according to the transmission efficiency correction factor η i , so as to obtain the final mass spectrum signal I i，corrected . η i The following calculation formula must be satisfied: the i =exp ; Where L is the length of the sampling tube, v is the airflow velocity in the process chamber, and k ads,i Let θ be the adsorption rate constant of plasma component i, and θ be the effective adsorption site coverage. I i，corrected The following calculation formula must be satisfied: I i,corrected =I i,raw / η i ; Among them, I i，raw This is the initial mass spectrum signal; The temperature control unit includes a temperature control tube, a heating element, and a temperature sensor; The temperature control tube is sleeved on the ceramic tube, and the temperature control tube is divided into several temperature control sections along its axial direction. Each temperature control section is provided with an installation groove and a cooling channel. The temperature sensor is located in the mounting groove and is used to detect the temperature inside the ceramic tube; The heating element is attached to the inner wall of the temperature control tube, and the heating element in each temperature control segment is independently temperature controlled; The controller is electrically connected to both the heating element and the temperature sensor, and is used to control the heating temperature of the heating element and to control the delivery of coolant to the cooling channel, so as to adjust the temperature of the ceramic tube in real time. The controller includes a gradient temperature control unit; The gradient temperature control unit is electrically connected to the acquisition unit. The gradient temperature control unit is used to set the target axial temperature gradient and control the power of the heating element in each temperature control segment so that the error between the temperature signal detected by the temperature sensor and the set target axial temperature gradient is within ±1℃.

2. The plasma mass spectrometry monitoring system according to claim 1, characterized in that, The sampling tube includes a ceramic tube and a protective tube; The ceramic tube has a sampling hole on its side wall near one end, and the other end of the ceramic tube is connected to the ionization module. The temperature control unit is fitted onto the ceramic tube and covers the outer wall of the ceramic tube; The protective tube is fitted onto the temperature control unit.

3. The plasma mass spectrometry monitoring system according to claim 2, characterized in that, The temperature control unit and the protective tube are filled with heat-insulating material; and / or, The sampling tube is sealed to the process chamber by a flexible sealing sleeve.

4. The plasma mass spectrometry monitoring system according to claim 1, characterized in that, The ionization module includes an ionization cavity and a dual-mode adjustable ionization source; The ionization cavity is connected to the sampling module; The dual-mode adjustable ionization source is located inside the ionization cavity. The dual-mode adjustable ionization source includes an electron bombardment ionization unit and a dielectric barrier discharge ionization unit. The electron bombardment ionization unit and the dielectric barrier discharge ionization unit can be started individually or all of them to achieve three ionization working modes.

5. The plasma mass spectrometry monitoring system according to claim 4, characterized in that, It also includes vacuum pumps; The ionization chamber is equipped with a partition, which divides the ionization chamber into a first chamber and a second chamber. A flow-limiting hole is formed on the partition, which connects the first chamber and the second chamber. An air inlet and a suction hole are formed on the side wall of the first chamber. The dielectric barrier discharge ionization unit is disposed in the first chamber, and the first chamber is connected to the sampling tube; The air inlet is used to connect to the air supply unit; The vacuum pump is connected to the suction port; The electron bombardment ionization unit is located in the second chamber.

6. The plasma mass spectrometry monitoring system according to claim 4, characterized in that, The mass spectrometry analysis module includes a mass spectrometry analysis cavity, an ion optical system, a mass analyzer, a detection unit, and a vacuum system; The mass spectrometry analysis chamber is connected to the ionization chamber; The ion optical system is located on one side wall of the mass spectrometry analysis cavity and extends into the ionization cavity, and is used to focus the ion beam and inject it into the mass analyzer. The mass analyzer is located inside the mass spectrometry analysis cavity and close to the ion optical system, and is used to analyze the ion beam; The detection unit is located inside the mass spectrometry analysis cavity and close to the mass analyzer, and is used to detect ions; The vacuum system is connected to the mass spectrometry analysis chamber and is used to adjust the vacuum environment inside the mass spectrometry analysis chamber.

7. A plasma mass spectrometry monitoring method, characterized in that, The method using the plasma mass spectrometry monitoring system according to any one of claims 1 to 6 includes the following steps: A movable sampling module is controlled to extend a sampling tube into a predetermined position within a process chamber to acquire plasma at a specific location within the process chamber; wherein, the specific location includes the position between the boundary layer and the central region within the process chamber. A target axial temperature gradient is set on the temperature control unit, and the temperature control unit is controlled to adjust the temperature inside the sampling tube in real time. Activate the ionization module to ionize the plasma; The mass spectrometry analysis module is activated to create a vacuum environment inside the module, and the ionized ions are analyzed and detected to obtain an initial mass spectrometry signal. The data processing module acquires the initial mass spectrum signal and calculates the final mass spectrum signal; The above steps are used to sample and analyze plasma at different locations within the process cavity to obtain spatial distribution information of the plasma.

8. The plasma mass spectrometry monitoring method according to claim 7, characterized in that, The step of setting a target axial temperature gradient on the temperature control unit and controlling the temperature control unit to adjust the temperature inside the sampling tube in real time includes: The temperature control tube within the temperature control unit is sequentially divided into several temperature control segments; Based on the set target axial temperature gradient, the temperature of each temperature control segment is controlled to make the temperature in the sampling tube gradient between 180℃ and 80℃. The temperature control unit adjusts the temperature in the temperature control section in real time so that the error between the actual temperature in the sampling tube and the set target temperature is within ±1℃.

9. The plasma mass spectrometry monitoring method according to claim 7, characterized in that, The ionization initiation module is used to ionize the plasma, including: The ionization module has three ionization operating modes: Turn off the electron bombardment ionization unit in the ionization module and turn on the dielectric barrier discharge ionization unit in the ionization module; Turn on the electron bombardment ionization unit and turn off the dielectric barrier discharge ionization unit; First, activate the dielectric barrier discharge ionization unit, and then activate the electron bombardment ionization unit.

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